diff --git a/modules/lstream/index.d.ts b/modules/lstream/index.d.ts
index e3af16eb..47aa20e1 100644
--- a/modules/lstream/index.d.ts
+++ b/modules/lstream/index.d.ts
@@ -52,7 +52,7 @@ export function distinctState<T>(initialValue: T): StateStream<T>;
 
 export function externalState<T>(get: any, set: any): StateStream<T>;
 
-export function never<T>(): Stream<T>
+export function never<T>(): Emitter<T>
 
 export function constant<T>(value: T): Stream<T>
 
diff --git a/modules/lstream/never.js b/modules/lstream/never.js
index 0b3a6880..6865dbae 100644
--- a/modules/lstream/never.js
+++ b/modules/lstream/never.js
@@ -6,6 +6,9 @@ export class NeverStream extends StreamBase {
   attach(observer) {
     return NOOP;
   }
+
+  next(value) {
+  }
 }
 
 NeverStream.INSTANCE = new NeverStream();
diff --git a/web/app/math/csys.ts b/modules/math/csys.ts
similarity index 64%
rename from web/app/math/csys.ts
rename to modules/math/csys.ts
index 33ffc5e6..f6f16291 100644
--- a/web/app/math/csys.ts
+++ b/modules/math/csys.ts
@@ -30,25 +30,27 @@ export default class CSys {
   w() {
     return this.z.dot(this.origin);
   }
-  
+
+  get outTransformation3x3() {
+    return new Matrix3().setBasisAxises(this.x, this.y, this.z);
+  }
+
   get outTransformation() {
-    if (!this._outTr) {
-      const mx = new Matrix3().setBasisAxises(this.x, this.y, this.z);
-      mx.tx = this.origin.x;
-      mx.ty = this.origin.y;
-      mx.tz = this.origin.z;
-      this._outTr = mx;
-    }
-    return this._outTr;
+    const mx = new Matrix3().setBasisAxises(this.x, this.y, this.z);
+    mx.tx = this.origin.x;
+    mx.ty = this.origin.y;
+    mx.tz = this.origin.z;
+    return mx;
+  }
+
+  get inTransformation3x3() {
+    return this.outTransformation3x3.invert();
   }
 
   get inTransformation() {
-    if (!this._inTr) {
-      this._inTr = this.outTransformation.invert();
-    }
-    return this._inTr;
+    return this.outTransformation.invert();
   }
-  
+
   copy(csys) {
     this.origin.setV(csys.origin);
     this.x.setV(csys.x);
@@ -65,7 +67,16 @@ export default class CSys {
     this.origin.set(x, y, z);
     return this;
   }
-  
+
+  invert() {
+    const tr = this.inTransformation;
+    return new CSys(
+      new Vector(tr.tx,  tr.ty,  tr.tz),
+      new Vector(tr.mxx, tr.myx, tr.mzx),
+      new Vector(tr.mxy, tr.myy, tr.mzy),
+      new Vector(tr.mxz, tr.myz, tr.mzz)
+    );
+  }
 }
 
 CSys.ORIGIN = CSys.origin();
diff --git a/modules/math/l3space.ts b/modules/math/l3space.ts
new file mode 100644
index 00000000..207f851f
--- /dev/null
+++ b/modules/math/l3space.ts
@@ -0,0 +1,371 @@
+import Vector from 'math/vector';
+
+export type Basis = [Vector, Vector, Vector];
+
+export type Vec3 = [number, number, number];
+
+const freeze = Object.freeze;
+
+const ORIGIN = freeze(new Vector(0, 0, 0));
+
+const AXIS = freeze({
+  X: freeze(new Vector(1, 0, 0)),
+  Y: freeze(new Vector(0, 1, 0)),
+  Z: freeze(new Vector(0, 0, 1))
+});
+
+// @ts-ignore
+const IDENTITY_BASIS: Basis = Object.freeze([AXIS.X, AXIS.Y, AXIS.Z]);
+
+export const STANDARD_BASES = freeze({
+  'XY': IDENTITY_BASIS,
+  'XZ': [AXIS.X, AXIS.Z, AXIS.Y],
+  'ZY': [AXIS.Z, AXIS.Y, AXIS.X]
+});
+
+export class Matrix3 {
+
+  mxx: number = 1;
+  mxy: number = 0;
+  mxz: number = 0;
+  tx:  number = 0;
+  myx: number = 0;
+  myy: number = 1;
+  myz: number = 0;
+  ty:  number = 0;
+  mzx: number = 0;
+  mzy: number = 0;
+  mzz: number = 1;
+  tz:  number = 0;
+
+  reset(): Matrix3 {
+    this.mxx = 1;
+    this.mxy = 0;
+    this.mxz = 0;
+    this.tx  = 0;
+    this.myx = 0;
+    this.myy = 1;
+    this.myz = 0;
+    this.ty  = 0;
+    this.mzx = 0;
+    this.mzy = 0;
+    this.mzz = 1;
+    this.tz  = 0;
+    return this;
+  };
+
+  setBasis(basis: [Vector, Vector, Vector]): Matrix3 {
+    var b = basis;
+    this.mxx = b[0].x;
+    this.mxy = b[1].x;
+    this.mxz = b[2].x;
+    this.tx = 0;
+    this.myx = b[0].y;
+    this.myy = b[1].y;
+    this.myz = b[2].y;
+    this.ty = 0;
+    this.mzx = b[0].z;
+    this.mzy = b[1].z;
+    this.mzz = b[2].z;
+    this.tz = 0;
+    return this;
+  };
+
+  setBasisAxises(x: Vector, y: Vector, z: Vector): Matrix3 {
+    this.mxx = x.x;
+    this.mxy = y.x;
+    this.mxz = z.x;
+    this.tx = 0;
+    this.myx = x.y;
+    this.myy = y.y;
+    this.myz = z.y;
+    this.ty = 0;
+    this.mzx = x.z;
+    this.mzy = y.z;
+    this.mzz = z.z;
+    this.tz = 0;
+    return this;
+  };
+
+  setBasisAndTranslation(basis: [Vector, Vector, Vector], translation: Vector): Matrix3 {
+    this.setBasis(basis);
+    this.tx = translation.x;
+    this.ty = translation.y;
+    this.tz = translation.z;
+    return this;
+  };
+
+  scale(dx: number, dy: number, dz: number): Matrix3{
+    this.mxx *= dx;
+    this.myy *= dy;
+    this.mzz *= dz;
+    return this;
+  };
+
+  translate(dx: number, dy: number, dz: number): Matrix3 {
+    this.tx += dx;
+    this.ty += dy;
+    this.tz += dz;
+    return this;
+  };
+
+  set3(
+    mxx: number, mxy: number, mxz: number,
+    myx: number, myy: number, myz: number,
+    mzx: number, mzy: number, mzz: number
+  ): Matrix3 {
+    this.mxx = mxx;
+    this.mxy = mxy;
+    this.mxz = mxz;
+    this.myx = myx;
+    this.myy = myy;
+    this.myz = myz;
+    this.mzx = mzx;
+    this.mzy = mzy;
+    this.mzz = mzz;
+    return this;
+  };
+
+  set34(
+    mxx: number, mxy: number, mxz: number, tx: number,
+    myx: number, myy: number, myz: number, ty: number,
+    mzx: number, mzy: number, mzz: number, tz: number
+  ): Matrix3 {
+    this.mxx = mxx;
+    this.mxy = mxy;
+    this.mxz = mxz;
+    this.tx = tx;
+    this.myx = myx;
+    this.myy = myy;
+    this.myz = myz;
+    this.ty = ty;
+    this.mzx = mzx;
+    this.mzy = mzy;
+    this.mzz = mzz;
+    this.tz = tz;
+    return this;
+  };
+
+  setMatrix(m: Matrix3): Matrix3 {
+    this.mxx = m.mxx;
+    this.mxy = m.mxy;
+    this.mxz = m.mxz;
+    this.tx = m.tx;
+    this.myx = m.myx;
+    this.myy = m.myy;
+    this.myz = m.myz;
+    this.ty = m.ty;
+    this.mzx = m.mzx;
+    this.mzy = m.mzy;
+    this.mzz = m.mzz;
+    this.tz = m.tz;
+    return this;
+  };
+
+  setToMatrix(m: any): void {
+    m.set(
+      this.mxx, this.mxy, this.mxz, this.tx,
+      this.myx, this.myy, this.myz, this.ty,
+      this.mzx, this.mzy, this.mzz, this.tz,
+      0, 0, 0, 1
+    );
+  };
+
+  toArray(): [[number, number, number, number],[number, number, number, number],[number, number, number, number]] {
+    return [
+      [this.mxx, this.mxy, this.mxz, this.tx],
+      [this.myx, this.myy, this.myz, this.ty],
+      [this.mzx, this.mzy, this.mzz, this.tz]
+    ];
+  };
+
+  invert(): Matrix3 {
+    return this.__invert(new Matrix3());
+  };
+
+  _invert(): Matrix3 {
+    return this.__invert(this);
+  };
+
+  __invert(out: Matrix3): Matrix3 {
+
+    var det =
+      this.mxx * (this.myy * this.mzz - this.mzy * this.myz) +
+      this.mxy * (this.myz * this.mzx - this.mzz * this.myx) +
+      this.mxz * (this.myx * this.mzy - this.mzx * this.myy);
+
+    if (det == 0.0) {
+      return null;
+    }
+
+    var cxx = this.myy * this.mzz - this.myz * this.mzy;
+    var cyx = -this.myx * this.mzz + this.myz * this.mzx;
+    var czx = this.myx * this.mzy - this.myy * this.mzx;
+    var cxt = -this.mxy * (this.myz * this.tz - this.mzz * this.ty)
+      - this.mxz * (this.ty * this.mzy - this.tz * this.myy)
+      - this.tx * (this.myy * this.mzz - this.mzy * this.myz);
+    var cxy = -this.mxy * this.mzz + this.mxz * this.mzy;
+    var cyy = this.mxx * this.mzz - this.mxz * this.mzx;
+    var czy = -this.mxx * this.mzy + this.mxy * this.mzx;
+    var cyt = this.mxx * (this.myz * this.tz - this.mzz * this.ty)
+      + this.mxz * (this.ty * this.mzx - this.tz * this.myx)
+      + this.tx * (this.myx * this.mzz - this.mzx * this.myz);
+    var cxz = this.mxy * this.myz - this.mxz * this.myy;
+    var cyz = -this.mxx * this.myz + this.mxz * this.myx;
+    var czz = this.mxx * this.myy - this.mxy * this.myx;
+    var czt = -this.mxx * (this.myy * this.tz - this.mzy * this.ty)
+      - this.mxy * (this.ty * this.mzx - this.tz * this.myx)
+      - this.tx * (this.myx * this.mzy - this.mzx * this.myy);
+
+    out.mxx = cxx / det;
+    out.mxy = cxy / det;
+    out.mxz = cxz / det;
+    out.tx = cxt / det;
+    out.myx = cyx / det;
+    out.myy = cyy / det;
+    out.myz = cyz / det;
+    out.ty = cyt / det;
+    out.mzx = czx / det;
+    out.mzy = czy / det;
+    out.mzz = czz / det;
+    out.tz = czt / det;
+    return out;
+  };
+
+  combine(transform: Matrix3, out?: Matrix3): Matrix3 {
+    var txx = transform.mxx;
+    var txy = transform.mxy;
+    var txz = transform.mxz;
+    var ttx = transform.tx;
+    var tyx = transform.myx;
+    var tyy = transform.myy;
+    var tyz = transform.myz;
+    var tty = transform.ty;
+    var tzx = transform.mzx;
+    var tzy = transform.mzy;
+    var tzz = transform.mzz;
+    var ttz = transform.tz;
+
+    var m = out || new Matrix3();
+    m.mxx = (this.mxx * txx + this.mxy * tyx + this.mxz * tzx);
+    m.mxy = (this.mxx * txy + this.mxy * tyy + this.mxz * tzy);
+    m.mxz = (this.mxx * txz + this.mxy * tyz + this.mxz * tzz);
+    m.tx = (this.mxx * ttx + this.mxy * tty + this.mxz * ttz + this.tx);
+    m.myx = (this.myx * txx + this.myy * tyx + this.myz * tzx);
+    m.myy = (this.myx * txy + this.myy * tyy + this.myz * tzy);
+    m.myz = (this.myx * txz + this.myy * tyz + this.myz * tzz);
+    m.ty = (this.myx * ttx + this.myy * tty + this.myz * ttz + this.ty);
+    m.mzx = (this.mzx * txx + this.mzy * tyx + this.mzz * tzx);
+    m.mzy = (this.mzx * txy + this.mzy * tyy + this.mzz * tzy);
+    m.mzz = (this.mzx * txz + this.mzy * tyz + this.mzz * tzz);
+    m.tz = (this.mzx * ttx + this.mzy * tty + this.mzz * ttz + this.tz);
+
+    return m;
+  };
+
+  _apply(vector: Vector): Vector {
+    return this.__apply(vector, vector);
+  };
+
+  __apply(vector: Vector, out: Vector): Vector {
+    let x = vector.x;
+    let y = vector.y;
+    let z = vector.z;
+    out.x = this.mxx * x + this.mxy * y + this.mxz * z + this.tx;
+    out.y = this.myx * x + this.myy * y + this.myz * z + this.ty;
+    out.z = this.mzx * x + this.mzy * y + this.mzz * z + this.tz;
+    return out;
+  };
+
+  apply3(data: Vec3): Vec3 {
+    return this.__apply3(data, [0,0,0])
+  };
+
+  _apply3(data: Vec3): Vec3 {
+    return this.__apply3(data, data);
+  };
+
+  __apply3([x, y, z]: Vec3, out: Vec3): Vec3 {
+    out[0] = this.mxx * x + this.mxy * y + this.mxz * z + this.tx;
+    out[1] = this.myx * x + this.myy * y + this.myz * z + this.ty;
+    out[2] = this.mzx * x + this.mzy * y + this.mzz * z + this.tz;
+    return out;
+  };
+
+  rotateWithSphericalAxis(axisAzimuth: number, axisInclination: number, angle: number, pivot: Vector) {
+
+    const axis = new Vector(
+      Math.sin(axisAzimuth) * Math.cos(axisInclination),
+      Math.sin(axisAzimuth) * Math.sin(axisInclination),
+      Math.cos(axisAzimuth)
+    );
+
+    return Matrix3.rotateMatrix(angle, axis, pivot, this);
+  };
+
+  rotate(angle: number, axis: Vector, pivot: Vector) {
+    return Matrix3.rotateMatrix(angle, axis, pivot, this);
+  };
+
+  static rotateMatrix(angle: number, axis: Vector, pivot: Vector, matrix: Matrix3): Matrix3 {
+    var sin = Math.sin(angle);
+    var cos = Math.cos(angle);
+    var axisX, axisY, axisZ;
+    var m = matrix || new Matrix3();
+
+    if (axis === AXIS.X || axis === AXIS.Y || axis === AXIS.Z) {
+      axisX = axis.x;
+      axisY = axis.y;
+      axisZ = axis.z;
+    } else {
+      // normalize
+      var mag = axis.length();
+
+      if (mag == 0.0) {
+        return m;
+      } else {
+        axisX = axis.x / mag;
+        axisY = axis.y / mag;
+        axisZ = axis.z / mag;
+      }
+    }
+
+    var px = pivot.x;
+    var py = pivot.y;
+    var pz = pivot.z;
+
+    m.mxx = cos + axisX * axisX * (1 - cos);
+    m.mxy = axisX * axisY * (1 - cos) - axisZ * sin;
+    m.mxz = axisX * axisZ * (1 - cos) + axisY * sin;
+
+    m.tx = px * (1 - m.mxx) - py * m.mxy - pz * m.mxz;
+
+    m.myx = axisY * axisX * (1 - cos) + axisZ * sin;
+    m.myy = cos + axisY * axisY * (1 - cos);
+    m.myz = axisY * axisZ * (1 - cos) - axisX * sin;
+    m.ty = py * (1 - m.myy) - px * m.myx - pz * m.myz;
+
+    m.mzx = axisZ * axisX * (1 - cos) - axisY * sin;
+    m.mzy = axisZ * axisY * (1 - cos) + axisX * sin;
+    m.mzz = cos + axisZ * axisZ * (1 - cos);
+    m.tz = pz * (1 - m.mzz) - px * m.mzx - py * m.mzy;
+    return m;
+  };
+
+  apply = vector => this.__apply(vector, new Vector());
+}
+
+
+function BasisForPlane(normal: Vector, alignY: Vector = AXIS.Y, alignZ: Vector = AXIS.Z): [number, number, Vector] {
+  let alignPlane, x, y;
+  if (Math.abs(normal.dot(alignY)) < 0.5) {
+    alignPlane = normal.cross(alignY);
+  } else {
+    alignPlane = normal.cross(alignZ);
+  }
+  y = alignPlane.cross(normal);
+  x = y.cross(normal);
+  return [x, y, normal];
+}
+
+export {ORIGIN, IDENTITY_BASIS, AXIS, BasisForPlane};
\ No newline at end of file
diff --git a/modules/math/quaternion.ts b/modules/math/quaternion.ts
new file mode 100644
index 00000000..3849c3b2
--- /dev/null
+++ b/modules/math/quaternion.ts
@@ -0,0 +1,34 @@
+
+
+export class Quaternion {
+
+  x: number = 0;
+  y: number = 0;
+  z: number = 0;
+  w: number = 1;
+
+
+  setAxisAndAngle(axisX, axisY, axisZ, angle) {
+    const halfAngle = angle/2;
+    const sin = Math.sin(halfAngle);
+    this.x = axisX*sin;
+    this.y = axisY*sin;
+    this.z = axisZ*sin;
+    this.w = Math.cos(halfAngle);
+
+    return this;
+  }
+
+  setSphericalAxisAndAngle(azimuth, inclination, angle) {
+
+    this.setAxisAndAngle(
+      Math.sin(azimuth) * Math.cos(inclination),
+      Math.sin(azimuth) * Math.sin(inclination),
+      Math.cos(azimuth),
+      angle
+    );
+
+    return this;
+  }
+
+}
\ No newline at end of file
diff --git a/modules/scene/cameraControlRenderer.js b/modules/scene/cameraControlRenderer.js
index df67e668..8d787938 100644
--- a/modules/scene/cameraControlRenderer.js
+++ b/modules/scene/cameraControlRenderer.js
@@ -2,7 +2,7 @@ import {AmbientLight, PerspectiveCamera, Scene, SpotLight, WebGLRenderer} from '
 import DPR from '../dpr';
 import {MeshArrow} from './objects/auxiliary';
 import * as SceneGraph from './sceneGraph';
-import {AXIS} from '../../web/app/math/l3space';
+import {AXIS} from '../math/l3space';
 
 export default function(container) {
 
diff --git a/modules/scene/objects/scalableLine.js b/modules/scene/objects/scalableLine.js
index 285f1592..5a5368f2 100644
--- a/modules/scene/objects/scalableLine.js
+++ b/modules/scene/objects/scalableLine.js
@@ -3,7 +3,7 @@ import {advancePseudoFrenetFrame, frenetFrame, pseudoFrenetFrame} from '../../..
 import * as vec from 'math/vec';
 import {viewScaleFactor} from '../scaleHelper';
 import {arrToThree} from 'math/vectorAdapters';
-import {ORIGIN} from '../../../web/app/math/l3space';
+import {ORIGIN} from '../../math/l3space';
 import {getSceneSetup} from '../sceneSetup';
 import calcFaceNormal from '../utils/calcFaceNormal';
 
diff --git a/modules/ui/components/Folder.less b/modules/ui/components/Folder.less
index f22b07ae..a83f2352 100644
--- a/modules/ui/components/Folder.less
+++ b/modules/ui/components/Folder.less
@@ -1,7 +1,6 @@
 @import "~ui/styles/theme.less";
 
 .root {
-  background-color: @bg-color-2;
 }
 
 .title {
diff --git a/modules/ui/components/GenericWizard.tsx b/modules/ui/components/GenericWizard.tsx
new file mode 100644
index 00000000..58f1a800
--- /dev/null
+++ b/modules/ui/components/GenericWizard.tsx
@@ -0,0 +1,44 @@
+import React from 'react';
+import Window, {WindowControlButton, WindowProps} from 'ui/components/Window';
+import {DocumentationTopic$} from "doc/DocumentationWindow";
+import {IoMdHelp} from "react-icons/io";
+import cx from 'classnames';
+import Stack from "ui/components/Stack";
+import ButtonGroup from "ui/components/controls/ButtonGroup";
+import Button from "ui/components/controls/Button";
+
+export function GenericWizard({topicId, title, left, className, children, onCancel, onOK, infoText, ...props}: {
+  topicId: string,
+  title: string,
+  left?: number,
+  onCancel: () => any,
+  onOK: () => any,
+  infoText: string
+} & WindowProps ) {
+
+  return <Window initWidth={250}
+                   initLeft={left || 15}
+                   title={(title||'').toUpperCase()}
+                   className={cx('mid-typography', className)}
+                   controlButtons={<>
+                     <WindowControlButton title='help' onClick={(e) => DocumentationTopic$.next({
+                       topic: topicId,
+                       x: e.pageX + 40,
+                       y: e.pageY
+                     })}>
+                       <IoMdHelp />
+                     </WindowControlButton>
+                   </>} {...props} >
+    {children}
+    <Stack>
+      <ButtonGroup>
+        <Button className='dialog-cancel' onClick={onCancel}>Cancel</Button>
+        <Button className='dialog-ok' type='accent' onClick={onOK}>OK</Button>
+      </ButtonGroup>
+      {infoText}
+    </Stack>
+
+  </Window>
+}
+
+
diff --git a/modules/ui/components/Window.tsx b/modules/ui/components/Window.tsx
index ed53f000..556c5de0 100644
--- a/modules/ui/components/Window.tsx
+++ b/modules/ui/components/Window.tsx
@@ -323,7 +323,7 @@ function _maskTest(mask, value) {
 export function WindowControlButton({danger, ...props}: {
   danger?: boolean;
   children: any;
-  onClick: () => void;
-  } & JSX.IntrinsicAttributes) {
+  onClick: (e: any) => any;
+  } & React.HTMLAttributes<HTMLSpanElement>) {
   return <span className={cx(ls.button, danger&&ls.danger)} {...props} />;
 }
\ No newline at end of file
diff --git a/modules/ui/components/controls/ButtonGroup.jsx b/modules/ui/components/controls/ButtonGroup.tsx
similarity index 61%
rename from modules/ui/components/controls/ButtonGroup.jsx
rename to modules/ui/components/controls/ButtonGroup.tsx
index 85f888de..ad5a10fe 100644
--- a/modules/ui/components/controls/ButtonGroup.jsx
+++ b/modules/ui/components/controls/ButtonGroup.tsx
@@ -3,7 +3,7 @@ import React from 'react';
 import ls from './ButtonGroup.less'
 import cx from 'classnames';
 
-export default function ButtonGroup({className, ...props}) {
+export default function ButtonGroup({className, ...props}: React.HTMLAttributes<HTMLSpanElement>) {
 
   return <div className={cx(ls.root, className)} {...props}/>;
 
diff --git a/modules/ui/components/controls/NumberControl.jsx b/modules/ui/components/controls/NumberControl.jsx
index d56f9db9..91226655 100644
--- a/modules/ui/components/controls/NumberControl.jsx
+++ b/modules/ui/components/controls/NumberControl.jsx
@@ -1,52 +1,59 @@
-import React from 'react';
+import React, {useCallback, useRef} from 'react';
 import PropTypes from 'prop-types';
 import InputControl from './InputControl';
 
-export default class NumberControl extends React.Component {
-  
-  render() {
-    let {onChange, onFocus, value} = this.props;
-    return <InputControl type='number' 
-              onWheel={this.onWheel} 
-              value={ value } 
-              onChange={this.onChange} 
-              onFocus={onFocus}
-              inputRef={input => this.input = input} /> 
-  }
-  
-  onChange = e => {
-    this.props.onChange(e.target.value);
+export default function NumberControl(props) {
+
+  let {onChange, onFocus, value} = props;
+
+  const onChangeFromTarget = e => {
+    onChange(e.target.value);
   };
-  
-  onWheel = (e) => {
-    let {baseStep, round, min, max, onChange, accelerator} = this.props;
-    let delta = e.deltaY;
-    let step = baseStep * (e.shiftKey ? accelerator : 1);
-    let val = parseFloat(e.target.value);
-    if (isNaN(val)) val = 0;
-    val = val + (delta < 0 ? -step : step);
-    if (min !== undefined && val < min) {
-      val = min;
+
+  const attachWheelListener = useCallback((input) => {
+    if (!input) {
+      return;
     }
-    if (max !== undefined && val > max) {
-      val = max;
-    }
-    if (round !== 0) {
-      val = val.toFixed(round);
-    }
-    this.input.value = val;
-    onChange(val);
-    // e.preventDefault();
-    e.stopPropagation();
-  }
+    const onWheel = (e) => {
+      let {baseStep, round, min, max, onChange, accelerator} = props;
+      let delta = e.shiftKey ? e.deltaX : e.deltaY;
+      let step = baseStep * (e.shiftKey ? accelerator : 1);
+      let val = parseFloat(e.target.value);
+      if (isNaN(val)) val = 0;
+      val = val + (delta < 0 ? -step : step);
+      if (min !== undefined && val < min) {
+        val = min;
+      }
+      if (max !== undefined && val > max) {
+        val = max;
+      }
+      if (round !== 0) {
+        val = val.toFixed(round);
+      }
+      input.value = val;
+      onChange(val);
+      e.preventDefault();
+      e.stopPropagation();
+    };
+    input.addEventListener('wheel', onWheel, {passive: false});
+  }, []);
+
+  return <InputControl type='number'
+                       value={value}
+                       onChange={onChangeFromTarget}
+                       onFocus={onFocus}
+                       inputRef={attachWheelListener}/>
+
 }
 
+
+
 NumberControl.propTypes = {
-  baseStep: PropTypes.number, 
-  round: PropTypes.number, 
-  min: PropTypes.number, 
-  max: PropTypes.number, 
-  accelerator: PropTypes.number, 
+  baseStep: PropTypes.number,
+  round: PropTypes.number,
+  min: PropTypes.number,
+  max: PropTypes.number,
+  accelerator: PropTypes.number,
   onChange: PropTypes.func.isRequired
 };
 
diff --git a/modules/ui/effects.ts b/modules/ui/effects.ts
index e5bb9ddb..d358636a 100644
--- a/modules/ui/effects.ts
+++ b/modules/ui/effects.ts
@@ -8,14 +8,14 @@ export function useStream<T>(getStream: (ctx: ApplicationContext) => Stream<T>)
   const basicStreams = useContext(StreamsContext);
   const [state, setState] = useState<{data: T}>();
 
-  const stream = typeof getStream === 'function' ? getStream(basicStreams) : getStream;
+  const stream = resolveStream(getStream, basicStreams);
 
   if (!stream) {
     console.log(getStream);
     throw "no stream ^";
   }
 
-  useEffect(() => stream.attach(data => setState({data})), EMPTY_ARR);
+  useEffect(() => stream.attach(data => setState({data})), [stream]);
 
   // @ts-ignore
   return state ? state.data : (stream.value !== undefined  ? stream.value : null);
@@ -26,7 +26,7 @@ export function useStreamWithUpdater<T>(getStream: (ctx: ApplicationContext) =>
   const data = useStream(getStream);
   const basicStreams = useContext(StreamsContext);
 
-  const stream = typeof getStream === 'function' ? getStream(basicStreams) : getStream;
+  const stream = resolveStream(getStream, basicStreams);
 
   const updater = useCallback((val) => {
 
@@ -41,5 +41,6 @@ export function useStreamWithUpdater<T>(getStream: (ctx: ApplicationContext) =>
 
 }
 
-
-const EMPTY_ARR = [];
\ No newline at end of file
+function resolveStream(getStream, basicStreams) {
+  return typeof getStream === 'function' ? getStream(basicStreams) : getStream
+}
diff --git a/test/coreTests/testCases/legacy/brep-bool.js b/test/coreTests/testCases/legacy/brep-bool.js
index c1d47683..594d8f9f 100644
--- a/test/coreTests/testCases/legacy/brep-bool.js
+++ b/test/coreTests/testCases/legacy/brep-bool.js
@@ -1,6 +1,6 @@
 import * as test from '../../test'
 import {deepMerge} from '../coreTests/utils/deep-merge'
-import {Matrix3} from '../../../../web/app/math/l3space'
+import {Matrix3} from '../../../../modules/math/l3space'
 
 const OPERANDS_MODE = false;
 
diff --git a/web/app/brep/brep-enclose.js b/web/app/brep/brep-enclose.js
index 43c4c993..63cbc2b3 100644
--- a/web/app/brep/brep-enclose.js
+++ b/web/app/brep/brep-enclose.js
@@ -3,7 +3,7 @@ import {Face} from './topo/face';
 import {Edge} from './topo/edge';
 import BrepCurve from './geom/curves/brepCurve';
 import {Plane} from './geom/impl/plane';
-import {BasisForPlane, Matrix3} from '../math/l3space';
+import {BasisForPlane, Matrix3} from 'math/l3space';
 import * as cad_utils from '../cad/cad-utils';
 import * as math from '../math/math';
 import {createBoundingSurface} from './brep-builder';
diff --git a/web/app/brep/brep-primitives.js b/web/app/brep/brep-primitives.js
index 37aabcb6..29996701 100644
--- a/web/app/brep/brep-primitives.js
+++ b/web/app/brep/brep-primitives.js
@@ -1,9 +1,9 @@
 import {Point} from './geom/point'
 import {Plane} from './geom/impl/plane'
 import {createPrism, enclose} from './brep-enclose'
-import {AXIS, Matrix3} from '../math/l3space'
+import {AXIS, Matrix3} from 'math/l3space'
 import {Circle} from '../cad/sketch/sketchModel'
-import CSys from '../math/csys';
+import CSys from 'math/csys';
 
 export function box(w, h, d, tr) {
   const wh = w * 0.5;
diff --git a/web/app/brep/geom/curves/brepCurve.js b/web/app/brep/geom/curves/brepCurve.js
index 8b5284a8..0f17933b 100644
--- a/web/app/brep/geom/curves/brepCurve.js
+++ b/web/app/brep/geom/curves/brepCurve.js
@@ -1,5 +1,5 @@
 import NurbsCurve from "./nurbsCurve";
-import {Matrix3} from '../../../math/l3space'
+import {Matrix3} from '../../../../../modules/math/l3space'
 import {areEqual} from '../../../math/math'
 
 import {eqSqTol, ueq, veq, veq3, veqNeg} from "../tolerance";
diff --git a/web/app/brep/geom/impl/plane.js b/web/app/brep/geom/impl/plane.js
index a4867fd4..826b9039 100644
--- a/web/app/brep/geom/impl/plane.js
+++ b/web/app/brep/geom/impl/plane.js
@@ -1,6 +1,6 @@
 import {Point} from '../point';
 import {Line} from './line';
-import {AXIS, BasisForPlane, Matrix3} from '../../../math/l3space';
+import {AXIS, BasisForPlane, Matrix3} from '../../../../../modules/math/l3space';
 import {eqTol, veq} from '../tolerance';
 
 export class Plane {
diff --git a/web/app/cad/actions/usabilityActions.js b/web/app/cad/actions/usabilityActions.js
index e559a27a..af2a52f8 100644
--- a/web/app/cad/actions/usabilityActions.js
+++ b/web/app/cad/actions/usabilityActions.js
@@ -1,4 +1,4 @@
-import {AXIS, ORIGIN} from '../../math/l3space';
+import {AXIS, ORIGIN} from '../../../../modules/math/l3space';
 import Vector from 'math/vector';
 import {RiCamera2Line} from "react-icons/ri";
 
diff --git a/web/app/cad/assembly/assembly.ts b/web/app/cad/assembly/assembly.ts
new file mode 100644
index 00000000..8140e211
--- /dev/null
+++ b/web/app/cad/assembly/assembly.ts
@@ -0,0 +1,145 @@
+import {MObject} from "../model/mobject";
+import {Param} from "../../sketcher/shapes/param";
+import Vector from "math/vector";
+import {Matrix3} from "math/l3space";
+import {ISolveStage, SolvableObject} from "../../sketcher/constr/solvableObject";
+import {AlgNumConstraint} from "../../sketcher/constr/ANConstraints";
+import {Constraints3D} from "./constraints3d";
+
+export abstract class AssemblyNode implements SolvableObject {
+
+  constraints: Set<AlgNumConstraint> = new Set();
+
+  model: MObject;
+
+  stage: ISolveStage;
+
+  id: string;
+
+  protected constructor(model: MObject) {
+    this.model = model;
+    this.id = 'assembly-node:' + model.id;
+  }
+
+  abstract visitParams(cb);
+
+  abstract reset();
+
+  createConsistencyConstraints(): AlgNumConstraint[] {
+    return [];
+  }
+
+  createRigidBodyLink(body: AssemblyCSysNode): AlgNumConstraint[] {
+    return [];
+  }
+
+  get params(): Param[] {
+    const paramArray = [];
+    this.visitParams(p => paramArray.push(p));
+    return paramArray;
+  }
+
+}
+
+export class AssemblyUnitVectorNode extends AssemblyNode {
+
+  x = new Param(0, 'X');
+  y = new Param(0, 'Y');
+  z = new Param(0, 'Z');
+  getVector: () => Vector;
+
+  constructor(model: MObject, getVector: () => Vector) {
+    super(model);
+    this.getVector = getVector;
+  }
+
+  visitParams(cb) {
+    cb(this.x);
+    cb(this.y);
+    cb(this.z);
+  }
+
+  reset() {
+    const {x, y, z} = this.getVector();
+    this.x.set(x);
+    this.y.set(y);
+    this.z.set(z);
+  }
+
+  createConsistencyConstraints() {
+    return [
+      new AlgNumConstraint(Constraints3D.UnitVectorConsistency, [this])
+    ];
+  }
+
+  createRigidBodyLink(body: AssemblyCSysNode) {
+    return [
+      new AlgNumConstraint(Constraints3D.RigidBodyLink3x3, [body, this])
+    ];
+  }
+
+}
+
+export class AssemblyCSysNode extends AssemblyNode {
+
+  ox = new Param(0, 'X');
+  oy = new Param(0, 'Y');
+  oz = new Param(0, 'Z');
+  ix = new Param(1, 'X');
+  iy = new Param(0, 'Y');
+  iz = new Param(0, 'Z');
+  jx = new Param(0, 'X');
+  jy = new Param(1, 'Y');
+  jz = new Param(0, 'Z');
+  kx = new Param(0, 'X');
+  ky = new Param(0, 'Y');
+  kz = new Param(1, 'Z');
+  getTransformation: () => Matrix3;
+
+  constructor(model: MObject, getTransformation: () => Matrix3) {
+    super(model);
+    this.getTransformation = getTransformation;
+  }
+
+  visitParams(cb) {
+    cb(this.ox);
+    cb(this.oy);
+    cb(this.oz);
+    cb(this.ix);
+    cb(this.iy);
+    cb(this.iz);
+    cb(this.jx);
+    cb(this.jy);
+    cb(this.jz);
+    cb(this.kx);
+    cb(this.ky);
+    cb(this.kz);
+  }
+
+  reset() {
+    const mx = this.getTransformation();
+    this.ox.set(mx.tx);
+    this.oy.set(mx.ty);
+    this.oz.set(mx.tz);
+
+    this.ix.set(mx.mxx);
+    this.iy.set(mx.myx);
+    this.iz.set(mx.mzx);
+
+    this.jx.set(mx.mxy);
+    this.jy.set(mx.myy);
+    this.jz.set(mx.mzy);
+
+    this.kx.set(mx.mxz);
+    this.ky.set(mx.myz);
+    this.kz.set(mx.mzz);
+
+  }
+
+  createConsistencyConstraints() {
+    return [
+      new AlgNumConstraint(Constraints3D.CSysConsistency, [this])
+    ];
+  }
+
+}
\ No newline at end of file
diff --git a/web/app/cad/assembly/assemblySolver.ts b/web/app/cad/assembly/assemblySolver.ts
new file mode 100644
index 00000000..aa0b40e5
--- /dev/null
+++ b/web/app/cad/assembly/assemblySolver.ts
@@ -0,0 +1,111 @@
+import {AlgNumConstraint} from "../../sketcher/constr/ANConstraints";
+import {AlgNumSubSystem} from "../../sketcher/constr/AlgNumSystem";
+import Vector from "math/vector";
+import CSys from "math/csys";
+import {AssemblyCSysNode, AssemblyNode} from "./assembly";
+import {ISolveStage} from "../../sketcher/constr/solvableObject";
+import {MObject} from "../model/mobject";
+import {MShell} from "../model/mshell";
+import {Constraints3D} from "./constraints3d";
+
+export function solveAssembly(constraints: AlgNumConstraint[]) {
+
+  const objects = new Set<AssemblyNode>();
+
+  constraints.forEach(c => c.objects.forEach(o => objects.add(o)));
+
+  const stage: ISolveStage = {
+    objects: objects,
+    index: 0
+  };
+
+  const roots = new Set<MShell>();
+  objects.forEach(o => {
+    const root = o.model.root;
+    if (root instanceof MShell) {
+      roots.add(root);
+      objects.add(root.assemblyNodes.location)
+    }
+  });
+
+  objects.forEach(o => {
+    o.stage = stage;
+    o.reset();
+  });
+
+  // const algNumConstraint = new AlgNumConstraint(Constraints3D.FaceParallel, objects);
+
+  const system = new AlgNumSubSystem(() => 0.001, val => val, stage);
+  // __DEBUG__.AddNormal(face1.csys.origin, new Vector().set3(objects[0].normal.map(p => p.get())))
+  // __DEBUG__.AddNormal(face2.csys.origin, new Vector().set3(objects[1].normal.map(p => p.get())))
+
+  system.startTransaction();
+  constraints.forEach(c => system.addConstraint(c));
+  objects.forEach(assemblyNode => {
+    const internalConstraints = assemblyNode.createConsistencyConstraints();
+    internalConstraints.forEach(c => {
+      c.internal = true;
+      system.addConstraint(c);
+    });
+
+    const root = assemblyNode.model.root;
+    if (root instanceof MShell) {
+      const rigidBodyLinks = assemblyNode.createRigidBodyLink(root.assemblyNodes.location);
+      rigidBodyLinks.forEach(c => {
+        c.internal = true;
+        system.addConstraint(c);
+      });
+    } else {
+      throw 'unsupported: needs location implementation';
+    }
+  });
+
+  system.prepare();
+  system.solveFine();
+  system.finishTransaction();
+
+  // __DEBUG__.AddNormal(face1.csys.origin, new Vector().set3(objects[0].normal.map(p => p.get())))
+  // __DEBUG__.AddNormal(face2.csys.origin, new Vector().set3(objects[1].normal.map(p => p.get())))
+
+  roots.forEach(root => {
+    applyResults(root, root.assemblyNodes.location);
+  });
+
+}
+
+
+function applyResults(shell: MShell, targetCsysParams: AssemblyCSysNode): void {
+  const [
+    ox, oy, oz, ix, iy, iz, jx, jy, jz, kx, ky, kz
+  ] = targetCsysParams.params.map(p => p.get());
+
+  const targetCsys = new CSys(
+    new Vector(ox, oy, oz),
+    new Vector(ix, iy, iz),
+    new Vector(jx, jy, jz),
+    new Vector(kx, ky, kz),
+  );
+
+  const basis = [
+    new Vector(ix, iy, iz),
+    new Vector(jx, jy, jz),
+    new Vector(kx, ky, kz),
+  ];
+
+  // __DEBUG__.AddCSys(shell.csys);
+  // __DEBUG__.AddCSys(targetCsys);
+
+  const tr = shell.csys.inTransformation3x3;
+  basis.forEach(r => tr._apply(r));
+
+  shell.location$.update(csys => {
+    return targetCsys;
+  });
+  // shell.location$.mutate(csys => {
+  //   csys.x = basis[0];
+  //   csys.y = basis[1];
+  //   csys.z = basis[2];
+  //   csys.origin = new Vector(ox, oy, oz)._minus(shell.csys.origin);
+  // });
+
+}
\ No newline at end of file
diff --git a/web/app/cad/assembly/constraints3d.ts b/web/app/cad/assembly/constraints3d.ts
new file mode 100644
index 00000000..08ac3f94
--- /dev/null
+++ b/web/app/cad/assembly/constraints3d.ts
@@ -0,0 +1,248 @@
+import {Polynomial, POW_1_FN, POW_2_FN} from "../../sketcher/constr/polynomial";
+import {NoIcon} from "../../sketcher/icons/NoIcon";
+import {AlgNumConstraint, ConstantsDefinitions, ConstraintSchema} from "../../sketcher/constr/ANConstraints";
+import {MObject} from "../model/mobject";
+import {SolvableObject} from "../../sketcher/constr/solvableObject";
+
+export const Constraints3D = {
+
+  FaceParallel: {
+    id: 'FaceParallel',
+    name: 'Face Parallel',
+    icon: NoIcon,
+
+    defineAssemblyScope: ([face1, face2]) => {
+      return [
+        face1.assemblyNodes.normal,
+        face2.assemblyNodes.normal
+      ];
+    },
+
+    defineParamsScope: ([n1, n2], cb) => {
+      n1.visitParams(cb);
+      n2.visitParams(cb);
+    },
+
+    collectPolynomials: (polynomials, params) => {
+
+      const [
+        nx1, ny1, nz1, nx2, ny2, nz2,
+      ] = params;
+
+      polynomials.push(
+        new Polynomial(1)
+          .monomial()
+            .term(nx1, POW_1_FN)
+            .term(nx2, POW_1_FN)
+          .monomial()
+            .term(ny1, POW_1_FN)
+            .term(ny2, POW_1_FN)
+          .monomial()
+            .term(nz1, POW_1_FN)
+            .term(nz2, POW_1_FN)
+
+      );
+
+    }
+
+  },
+
+  UnitVectorConsistency: {
+    id: 'UnitVectorConsistency',
+    name: 'UnitVectorConsistency',
+    icon: NoIcon,
+
+    defineParamsScope: ([vec], cb) => {
+      vec.visitParams(cb);
+    },
+
+    collectPolynomials: (polynomials, params) => {
+
+      const [x, y, z] = params;
+
+      polynomials.push(
+        new Polynomial(-1)
+          .monomial()
+            .term(x, POW_2_FN)
+          .monomial()
+            .term(y, POW_2_FN)
+          .monomial()
+            .term(z, POW_2_FN)
+      );
+    }
+  },
+
+  CSysConsistency: {
+    id: 'CSysConsistency',
+    name: 'CSysConsistency',
+    icon: NoIcon,
+
+    defineParamsScope: ([csys], cb) => {
+      cb(csys.ix);
+      cb(csys.iy);
+      cb(csys.iz);
+      cb(csys.jx);
+      cb(csys.jy);
+      cb(csys.jz);
+      cb(csys.kx);
+      cb(csys.ky);
+      cb(csys.kz);
+    },
+
+    collectPolynomials: (polynomials, params) => {
+
+      const [
+        ix,
+        iy,
+        iz,
+        jx,
+        jy,
+        jz,
+        kx,
+        ky,
+        kz] = params;
+
+      //let's keep matrix orthogonal and unit basis
+      polynomials.push(new Polynomial(0)
+        .monomial()
+        .term(ix, POW_1_FN)
+        .term(jx, POW_1_FN)
+        .monomial()
+        .term(iy, POW_1_FN)
+        .term(jy, POW_1_FN)
+        .monomial()
+        .term(iz, POW_1_FN)
+        .term(jz, POW_1_FN));
+
+      polynomials.push(new Polynomial(0)
+        .monomial()
+        .term(ix, POW_1_FN)
+        .term(kx, POW_1_FN)
+        .monomial()
+        .term(iy, POW_1_FN)
+        .term(ky, POW_1_FN)
+        .monomial()
+        .term(iz, POW_1_FN)
+        .term(kz, POW_1_FN));
+
+      polynomials.push(new Polynomial(0)
+        .monomial()
+        .term(jx, POW_1_FN)
+        .term(kx, POW_1_FN)
+        .monomial()
+        .term(jy, POW_1_FN)
+        .term(ky, POW_1_FN)
+        .monomial()
+        .term(jz, POW_1_FN)
+        .term(kz, POW_1_FN));
+
+      polynomials.push(new Polynomial(-1)
+        .monomial()
+        .term(ix, POW_2_FN)
+        .monomial()
+        .term(iy, POW_2_FN)
+        .monomial()
+        .term(iz, POW_2_FN));
+
+      polynomials.push(new Polynomial(-1)
+        .monomial()
+        .term(jx, POW_2_FN)
+        .monomial()
+        .term(jy, POW_2_FN)
+        .monomial()
+        .term(jz, POW_2_FN));
+
+      polynomials.push(new Polynomial(-1)
+        .monomial()
+        .term(kx, POW_2_FN)
+        .monomial()
+        .term(ky, POW_2_FN)
+        .monomial()
+        .term(kz, POW_2_FN));
+    },
+  },
+
+  RigidBodyLink3x3: {
+    id: 'RigidBodyLink3x3',
+    name: 'RigidBodyLink3x3',
+    icon: NoIcon,
+
+    defineParamsScope: ([csys, vec], cb) => {
+      cb(csys.ix);
+      cb(csys.iy);
+      cb(csys.iz);
+      cb(csys.jx);
+      cb(csys.jy);
+      cb(csys.jz);
+      cb(csys.kx);
+      cb(csys.ky);
+      cb(csys.kz);
+      vec.visitParams(cb);
+    },
+
+    collectPolynomials: (polynomials, params, _, objects) => {
+      const [csys, vec] = objects;
+
+      const {x: nStarX, y: nStarY, z: nStarZ} = vec.getVector();
+
+      const [ix, iy, iz, jx, jy, jz, kx, ky, kz, x, y, z] = params;
+
+      // out.x = this.mxx * x + this.mxy * y + this.mxz * z + this.tx;
+      // out.y = this.myx * x + this.myy * y + this.myz * z + this.ty;
+      // out.z = this.mzx * x + this.mzy * y + this.mzz * z + this.tz;
+
+      polynomials.push(
+        new Polynomial(0)
+          .monomial(-1)
+            .term(x, POW_1_FN)
+          .monomial(nStarX)
+            .term(ix, POW_1_FN)
+          .monomial(nStarY)
+            .term(jx, POW_1_FN)
+          .monomial(nStarZ)
+            .term(kx, POW_1_FN)
+      );
+
+      polynomials.push(
+        new Polynomial(0)
+          .monomial(-1)
+            .term(y, POW_1_FN)
+          .monomial(nStarX)
+            .term(iy, POW_1_FN)
+          .monomial(nStarY)
+            .term(jy, POW_1_FN)
+          .monomial(nStarZ)
+            .term(ky, POW_1_FN),
+
+      );
+
+      polynomials.push(
+        new Polynomial(0)
+          .monomial(-1)
+            .term(z, POW_1_FN)
+          .monomial(nStarX)
+            .term(iz, POW_1_FN)
+          .monomial(nStarY)
+            .term(jz, POW_1_FN)
+          .monomial(nStarZ)
+            .term(kz, POW_1_FN)
+      );
+
+    }
+  },
+
+};
+
+
+export interface AssemblyConstraintSchema extends ConstraintSchema {
+  defineAssemblyScope: (objects: MObject[]) => SolvableObject[],
+}
+
+
+export function createAssemblyConstraint(schema: AssemblyConstraintSchema,
+                                         objects: MObject[],
+                                         constants?: ConstantsDefinitions,
+                                         internal?: boolean = false) {
+
+  return new AlgNumConstraint(schema, schema.defineAssemblyScope(objects), constants, internal);
+}
\ No newline at end of file
diff --git a/web/app/cad/cad-utils.js b/web/app/cad/cad-utils.js
index 2ae6dc00..bee31e11 100644
--- a/web/app/cad/cad-utils.js
+++ b/web/app/cad/cad-utils.js
@@ -3,7 +3,7 @@ import BBox from '../math/bbox'
 import {HashTable} from '../utils/hashmap'
 import {Graph} from '../math/graph'
 import * as math from '../math/math'
-import {Matrix3, AXIS, ORIGIN} from '../math/l3space'
+import {Matrix3, AXIS, ORIGIN} from '../../../modules/math/l3space'
 import {MeshSceneSolid} from './scene/wrappers/meshSceneObject'
 
 export const FACE_COLOR =  0xB0C4DE;
diff --git a/web/app/cad/craft/cadRegistryPlugin.ts b/web/app/cad/craft/cadRegistryPlugin.ts
index 76e250ef..6fcb5276 100644
--- a/web/app/cad/craft/cadRegistryPlugin.ts
+++ b/web/app/cad/craft/cadRegistryPlugin.ts
@@ -56,9 +56,13 @@ export function activate(ctx: ApplicationContext) {
   function findEntity(entity, id) {
     return index().get(id);
   }
-  
+
+  function find(id) {
+    return index().get(id);
+  }
+
   services.cadRegistry = {
-    getAllShells, findShell, findFace, findEdge, findSketchObject, findEntity, findDatum, findDatumAxis, findLoop,
+    getAllShells, findShell, findFace, findEdge, findSketchObject, findEntity, findDatum, findDatumAxis, findLoop, find,
     get modelIndex() {
       return streams.cadRegistry.modelIndex.value;
     },
@@ -85,6 +89,7 @@ export interface CadRegistry {
   findDatum(id: string): MObject;
   findDatumAxis(id: string): MObject;
   findLoop(id: string): MObject;
+  find(id: string): MObject;
   modelIndex: Map<String, MObject>;
   models: MObject[];
   shells: MObject[];
diff --git a/web/app/cad/craft/cutExtrude/cutExtrude.js b/web/app/cad/craft/cutExtrude/cutExtrude.js
index 095cf473..0acbd44e 100644
--- a/web/app/cad/craft/cutExtrude/cutExtrude.js
+++ b/web/app/cad/craft/cutExtrude/cutExtrude.js
@@ -1,4 +1,4 @@
-import {Matrix3} from '../../../math/l3space'
+import {Matrix3} from '../../../../../modules/math/l3space'
 import * as math from '../../../math/math'
 import {enclose} from '../../../brep/brep-enclose'
 import {BooleanOperation, combineShells} from '../booleanOperation'
diff --git a/web/app/cad/craft/datum/create/createDatumOperation.js b/web/app/cad/craft/datum/create/createDatumOperation.js
index 62f937ad..f5b0bdef 100644
--- a/web/app/cad/craft/datum/create/createDatumOperation.js
+++ b/web/app/cad/craft/datum/create/createDatumOperation.js
@@ -2,7 +2,7 @@ import DatumWizard from './CreateDatumWizard';
 import schema from './createDatumOpSchema';
 import DatumObject3D from '../datumObject';
 import * as SceneGraph from 'scene/sceneGraph';
-import CSys from '../../../../math/csys';
+import CSys from '../../../../../../modules/math/csys';
 import {MDatum} from '../../../model/mdatum';
 import {roundInteractiveInput} from '../../wizard/roundUtils';
 import {DatumParamsRenderer} from '../DatumParamsRenderer';
diff --git a/web/app/cad/craft/datum/csysObject.js b/web/app/cad/craft/datum/csysObject.js
index eff38ba6..90b969a6 100644
--- a/web/app/cad/craft/datum/csysObject.js
+++ b/web/app/cad/craft/datum/csysObject.js
@@ -1,5 +1,5 @@
 import {MeshLambertMaterial, Object3D} from 'three';
-import {AXIS} from '../../../math/l3space';
+import {AXIS} from '../../../../../modules/math/l3space';
 import {MeshArrow} from 'scene/objects/auxiliary';
 import {viewScaleFactor} from '../../../../../modules/scene/scaleHelper';
 
diff --git a/web/app/cad/craft/datum/rotate/rotateDatumOperation.js b/web/app/cad/craft/datum/rotate/rotateDatumOperation.js
index 7187c0c4..7cbff395 100644
--- a/web/app/cad/craft/datum/rotate/rotateDatumOperation.js
+++ b/web/app/cad/craft/datum/rotate/rotateDatumOperation.js
@@ -1,7 +1,7 @@
 import schema from './rotateDatumOpSchema';
 import {MDatum} from '../../../model/mdatum';
 import RotateDatumWizard from './RotateDatumWizard';
-import {Matrix3, ORIGIN} from '../../../../math/l3space';
+import {Matrix3, ORIGIN} from '../../../../../../modules/math/l3space';
 import {DEG_RAD} from '../../../../math/math';
 
 
diff --git a/web/app/cad/craft/primitives/cone/coneOperation.js b/web/app/cad/craft/primitives/cone/coneOperation.js
index 8c5931c4..bc1ee8b0 100644
--- a/web/app/cad/craft/primitives/cone/coneOperation.js
+++ b/web/app/cad/craft/primitives/cone/coneOperation.js
@@ -2,7 +2,7 @@ import {Mesh, ConeGeometry, Matrix4, CylinderGeometry} from 'three';
 import schema from './coneOpSchema';
 import ConeWizard from './ConeWizard';
 import {IMAGINARY_SURFACE_MATERIAL} from '../../../preview/scenePreviewer';
-import CSys from '../../../../math/csys';
+import CSys from '../../../../../../modules/math/csys';
 import * as SceneGraph from '../../../../../../modules/scene/sceneGraph';
 import datumConsumingOperation from '../datumConsumingOperation';
 import {assignBooleanParams} from '../booleanOptionHelper';
diff --git a/web/app/cad/craft/primitives/datumConsumingOperation.js b/web/app/cad/craft/primitives/datumConsumingOperation.js
index a9e67e6d..1e6adc99 100644
--- a/web/app/cad/craft/primitives/datumConsumingOperation.js
+++ b/web/app/cad/craft/primitives/datumConsumingOperation.js
@@ -1,4 +1,4 @@
-import CSys from '../../../math/csys';
+import CSys from '../../../../../modules/math/csys';
 
 export default function datumConsumingOperation(params, services, run) {
   let mDatum = params.datum && services.cadRegistry.findDatum(params.datum);
diff --git a/web/app/cad/craft/primitives/primitivePreviewer.js b/web/app/cad/craft/primitives/primitivePreviewer.js
index 34dffad6..d39b7e08 100644
--- a/web/app/cad/craft/primitives/primitivePreviewer.js
+++ b/web/app/cad/craft/primitives/primitivePreviewer.js
@@ -1,6 +1,6 @@
 import {BoxGeometry, Matrix4, Mesh} from 'three';
 import {IMAGINARY_SURFACE_MATERIAL} from '../../preview/scenePreviewer';
-import CSys from '../../../math/csys';
+import CSys from '../../../../../modules/math/csys';
 import * as SceneGraph from '../../../../../modules/scene/sceneGraph';
 
 export default function primitivePreviewer(createThreePrimitiveGeometry, paramsToScales, shift) {
diff --git a/web/app/cad/craft/primitives/simplePlane/simplePlaneOperation.js b/web/app/cad/craft/primitives/simplePlane/simplePlaneOperation.js
index ecc0beaa..dc132e3a 100644
--- a/web/app/cad/craft/primitives/simplePlane/simplePlaneOperation.js
+++ b/web/app/cad/craft/primitives/simplePlane/simplePlaneOperation.js
@@ -1,5 +1,5 @@
 import {createMeshGeometry} from 'scene/geoms';
-import {STANDARD_BASES} from '../../../../math/l3space';
+import {STANDARD_BASES} from '../../../../../../modules/math/l3space';
 import {Plane} from '../../../../brep/geom/impl/plane';
 import Vector from 'math/vector';
 import PlaneWizard from './SimplePlaneWizard';
diff --git a/web/app/cad/craft/primitives/torus/torusOperation.js b/web/app/cad/craft/primitives/torus/torusOperation.js
index 7b7232e4..502068e3 100644
--- a/web/app/cad/craft/primitives/torus/torusOperation.js
+++ b/web/app/cad/craft/primitives/torus/torusOperation.js
@@ -2,7 +2,7 @@ import {Mesh, TorusGeometry} from 'three';
 import schema from './torusOpSchema';
 import TorusWizard from './TorusWizard';
 import {IMAGINARY_SURFACE_MATERIAL} from '../../../preview/scenePreviewer';
-import CSys from '../../../../math/csys';
+import CSys from '../../../../../../modules/math/csys';
 import * as SceneGraph from '../../../../../../modules/scene/sceneGraph';
 import datumConsumingOperation from '../datumConsumingOperation';
 import {assignBooleanParams} from '../booleanOptionHelper';
diff --git a/web/app/cad/craft/spatialCurve/spatialCurveOperation.js b/web/app/cad/craft/spatialCurve/spatialCurveOperation.js
index aff7d087..f0a06d94 100644
--- a/web/app/cad/craft/spatialCurve/spatialCurveOperation.js
+++ b/web/app/cad/craft/spatialCurve/spatialCurveOperation.js
@@ -1,4 +1,4 @@
-import CSys from '../../../math/csys';
+import CSys from '../../../../../modules/math/csys';
 import {MDatum} from '../../model/mdatum';
 
 import spatialCurveOpSchema from './spatialCurveOpSchema';
diff --git a/web/app/cad/craft/wizard/components/Wizard.jsx b/web/app/cad/craft/wizard/components/Wizard.jsx
index 40896ffa..78516e04 100644
--- a/web/app/cad/craft/wizard/components/Wizard.jsx
+++ b/web/app/cad/craft/wizard/components/Wizard.jsx
@@ -1,5 +1,4 @@
 import React from 'react';
-import Window, {WindowControlButton} from 'ui/components/Window';
 import Stack from 'ui/components/Stack';
 import Button from 'ui/components/controls/Button';
 import ButtonGroup from 'ui/components/controls/ButtonGroup';
@@ -9,8 +8,7 @@ import CadError from '../../../../utils/errors';
 import {FormContext} from './form/Form';
 import connect from 'ui/connect';
 import {combine} from 'lstream';
-import {DocumentationTopic$} from "../../../../../../modules/doc/DocumentationWindow";
-import {IoMdHelp} from "react-icons/io";
+import {GenericWizard} from "ui/components/GenericWizard";
 
 @connect((streams, props) => combine(props.context.workingRequest$, props.context.state$)
   .map(([workingRequest, state]) => ({
@@ -56,42 +54,31 @@ export default class Wizard extends React.Component {
     let Form = operation.form;
 
     const error = this.props.error;
-    return <Window initWidth={250}
-                   initLeft={left || 15}
+    return <GenericWizard
+                   left={left}
                    title={title}
                    onClose={this.cancel}
                    onKeyDown={this.onKeyDown}
                    setFocus={this.focusFirstInput}
-                   className='Wizard mid-typography'
+                   className='Wizard'
                    data-operation-id={operation.id}
-                   controlButtons={<>
-                     <WindowControlButton title='help' onClick={(e) => DocumentationTopic$.next({
-                       topic: operation.id,
-                       x: e.pageX + 40,
-                       y: e.pageY
-                     })}>
-                       <IoMdHelp />
-                     </WindowControlButton>
-                   </>}>
+                   topicId={operation.id}
+                   onCancel={this.cancel}
+                   onOK={this.onOK}
+                   infoText={error && <div className={ls.errorMessage}>
+                     {CadError.ALGORITHM_ERROR_KINDS.includes(error.kind) && <span>
+                        performing operation with current parameters leads to an invalid object
+                        (self-intersecting / zero-thickness / complete degeneration or unsupported cases)
+                      </span>}
+                     {error.code && <div className={ls.errorCode}>{error.code}</div>}
+                     {error.userMessage && <div className={ls.userErrorMessage}>{error.userMessage}</div>}
+                     {!error.userMessage && <div>internal error processing operation, check the log</div>}
+                   </div>}
+    >
       <FormContext.Provider value={formContext}>
         <Form/>
       </FormContext.Provider>
-      <Stack>
-        <ButtonGroup>
-          <Button className='dialog-cancel' onClick={this.cancel}>Cancel</Button>
-          <Button className='dialog-ok' type='accent' onClick={this.onOK}>OK</Button>
-        </ButtonGroup>
-        {error && <div className={ls.errorMessage}>
-          {CadError.ALGORITMTHM_ERROR_KINDS.includes(error.kind) && <span>
-            performing operation with current parameters leads to an invalid object
-            (self-intersecting / zero-thickness / complete degeneration or unsupported cases)
-          </span>}
-          {error.code && <div className={ls.errorCode}>{error.code}</div>}
-          {error.userMessage && <div className={ls.userErrorMessage}>{error.userMessage}</div>}
-          {!error.userMessage && <div>internal error processing operation, check the log</div>}
-        </div>}
-      </Stack>
-    </Window>;
+    </GenericWizard>;
   }
 
   onKeyDown = e => {
diff --git a/web/app/cad/debugPlugin.js b/web/app/cad/debugPlugin.js
index 9dfe27ff..818e829e 100644
--- a/web/app/cad/debugPlugin.js
+++ b/web/app/cad/debugPlugin.js
@@ -181,6 +181,12 @@ function addGlobalDebugActions({viewer, cadScene, cadRegistry}) {
     AddSurfaceNormal: (surface) => {     
       __DEBUG__.AddNormal(surface.pointInMiddle(), surface.normalInMiddle());
     },
+    AddCSys: (csys, scale) => {
+      scale = scale || 100;
+      __DEBUG__.AddNormal(csys.origin, csys.x, 0xff0000, scale)
+      __DEBUG__.AddNormal(csys.origin, csys.y, 0x00ff00, scale)
+      __DEBUG__.AddNormal(csys.origin, csys.z, 0x0000ff, scale)
+    },
     AddTessDump: (triangles, color) => {
       const vec = arr => new THREE.Vector3().fromArray(arr);
       color = color || 0xffffff;
diff --git a/web/app/cad/dom/components/ModellerContextualActions.tsx b/web/app/cad/dom/components/ModellerContextualActions.tsx
new file mode 100644
index 00000000..f1a66172
--- /dev/null
+++ b/web/app/cad/dom/components/ModellerContextualActions.tsx
@@ -0,0 +1,377 @@
+import React, {useContext} from 'react';
+import {AppContext} from "./AppContext";
+import {useStream} from "ui/effects";
+import {ApplicationContext} from "context";
+import {AlgNumSubSystem} from "../../../sketcher/constr/AlgNumSystem";
+import {ParallelConstraintIcon} from "../../../sketcher/icons/constraints/ConstraintIcons";
+import {DEG_RAD, makeAngle0_360} from "../../../math/math";
+import {AlgNumConstraint} from "../../../sketcher/constr/ANConstraints";
+import {Param} from "../../../sketcher/shapes/param";
+import {COS_FN, Polynomial, POW_1_FN, POW_2_FN, SIN_FN} from "../../../sketcher/constr/polynomial";
+import {Matrix3} from "math/l3space";
+import CSys from "math/csys";
+import Vector from "math/vector";
+import {Dialog} from "ui/components/Dialog";
+import {MObject} from "../../model/mobject";
+import {MBrepFace} from "../../model/mface";
+import {solveAssembly} from "../../assembly/assemblySolver";
+import {Constraints3D, createAssemblyConstraint} from "../../assembly/constraints3d";
+
+export function ModellerContextualActions({}) {
+
+  const ctx = useContext(AppContext);
+
+  const faceSelection: string[] = useStream(ctx => ctx.streams.selection.face);
+
+  if (faceSelection.length === 0) {
+    return null;
+  }
+
+  const actions = [];
+
+  if (faceSelection.length === 2) {
+
+    actions.push(<button key='faceParallel' onClick={() => faceParallel(ctx, faceSelection)}>Face Parallel</button>);
+
+  }
+
+  return <Dialog initRight={50} title='AVAILABLE ACTIONS' onClose={() => {}}>
+    {actions}
+  </Dialog>;
+}
+
+const XConstraints3D = {
+  FaceParallel: {
+    id: 'FaceParallel',
+    name: 'FaceParallel',
+    icon: ParallelConstraintIcon,
+
+    defineAssemblyScope: ([face1, face2], cb) => {
+      cb(face1.assemblyNodes.normal);
+      cb(face2.assemblyNodes.normal);
+    },
+
+    defineParamsScope: (objects, cb) => {
+
+      const [face1W, face2W, csys1W, csys2W] = objects;
+
+      const n1 = face1W.normal;
+      const n2 = face2W.normal;
+
+
+      const [nx1, ny1, nz1] = n1;
+      const [nx2, ny2, nz2] = n2;
+
+      const csysParams1 = csys1W.params;
+      const [
+        ox1, oy1, oz1, ix1, iy1, iz1, jx1, jy1, jz1, kx1, ky1, kz1
+      ] = csysParams1;
+
+      const csysParams2 = csys2W.params;
+      const [
+        ox2, oy2, oz2, ix2, iy2, iz2, jx2, jy2, jz2, kx2, ky2, kz2
+      ] = csysParams2;
+
+      [
+        nx1, ny1, nz1, nx2, ny2, nz2,
+        ox1, oy1, oz1, ix1, iy1, iz1, jx1, jy1, jz1, kx1, ky1, kz1,
+        ox2, oy2, oz2, ix2, iy2, iz2, jx2, jy2, jz2, kx2, ky2, kz2
+      ].forEach(cb);
+
+    },
+
+    collectPolynomials: (polynomials, params, constants, [face1, face2, csys1, csys2]) => {
+
+      const [
+        nx1, ny1, nz1, nx2, ny2, nz2,
+        ox1, oy1, oz1, ix1, iy1, iz1, jx1, jy1, jz1, kx1, ky1, kz1,
+        ox2, oy2, oz2, ix2, iy2, iz2, jx2, jy2, jz2, kx2, ky2, kz2
+      ] = params;
+
+      polynomials.push(
+        new Polynomial(1)
+          .monomial()
+            .term(nx1, POW_1_FN)
+            .term(nx2, POW_1_FN)
+          .monomial()
+            .term(ny1, POW_1_FN)
+            .term(ny2, POW_1_FN)
+          .monomial()
+            .term(nz1, POW_1_FN)
+            .term(nz2, POW_1_FN)
+      );
+
+      rigidBodyLink3x3(
+        [ix1, iy1, iz1, jx1, jy1, jz1, kx1, ky1, kz1],
+        csys1.csys,
+        face1.normal
+      ).forEach(p => polynomials.push(p));
+
+      rigidBodyLink3x3(
+        [ix2, iy2, iz2, jx2, jy2, jz2, kx2, ky2, kz2],
+        csys2.csys,
+        face2.normal
+      ).forEach(p => polynomials.push(p));
+
+      polynomials.push(
+        new Polynomial(-1)
+          .monomial()
+           .term(nx1, POW_2_FN)
+          .monomial()
+            .term(ny1, POW_2_FN)
+          .monomial()
+           .term(nz1, POW_2_FN)
+      );
+
+      polynomials.push(
+        new Polynomial(-1)
+          .monomial()
+            .term(nx2, POW_2_FN)
+          .monomial()
+            .term(ny2, POW_2_FN)
+          .monomial()
+            .term(nz2, POW_2_FN)
+      );
+
+    }
+
+  },
+
+};
+
+function vectorParams(vec) {
+  const {x, y, z} = vec;
+  return [new Param(x, 'X'), new Param(y, 'Y'), new Param(z, 'Z')];
+}
+
+function csysParams(csys) {
+  const {x, y, z} = csys.origin;
+  return [
+    new Param(x, 'X'),
+    new Param(y, 'Y'),
+    new Param(z, 'Z'),
+    new Param(csys.x.x, 'X'),
+    new Param(csys.x.y, 'Y'),
+    new Param(csys.x.z, 'Z'),
+    new Param(csys.y.x, 'X'),
+    new Param(csys.y.y, 'Y'),
+    new Param(csys.y.z, 'Z'),
+    new Param(csys.z.x, 'X'),
+    new Param(csys.z.y, 'Y'),
+    new Param(csys.z.z, 'Z')
+  ];
+}
+
+function faceWrapper(face: MBrepFace) {
+
+  return {
+    constraints: new Set(),
+    normal: vectorParams(face.normal()),
+    face,
+    visitParams(cb) {
+      this.normal.forEach(cb);
+    }
+
+  }
+
+}
+
+
+function csysWrapper(csys: CSys) {
+
+  return {
+    constraints: new Set(),
+    params: csysParams(csys),
+    csys,
+    visitParams(cb) {
+      this.params.forEach(cb);
+    }
+  }
+
+}
+function faceParallel(ctx: ApplicationContext, faceSelection: string[]) {
+
+  const [face1, face2] = faceSelection.map(id => ctx.cadRegistry.find(id));
+
+  const constraints = [
+    createAssemblyConstraint(Constraints3D.FaceParallel, [face1, face2])
+  ];
+
+  solveAssembly(constraints);
+}
+
+function faceParallelLegacy(ctx: ApplicationContext, faceSelection: string[]) {
+
+  const [face1, face2] = faceSelection.map(id => ctx.cadRegistry.find(id));
+
+  const stage = {};
+  const objects = [
+    faceWrapper(face1),
+    faceWrapper(face2),
+    csysWrapper(face1.shell.csys),
+    csysWrapper(face2.shell.csys),
+  ];
+  objects.forEach(o => o.stage = stage);
+  stage.objects = objects;
+  const algNumConstraint = new AlgNumConstraint(XConstraints3D.FaceParallel, objects);
+
+  const system = new AlgNumSubSystem(() => 0.001, val => val, stage);
+  // __DEBUG__.AddNormal(face1.csys.origin, new Vector().set3(objects[0].normal.map(p => p.get())))
+  // __DEBUG__.AddNormal(face2.csys.origin, new Vector().set3(objects[1].normal.map(p => p.get())))
+
+  system.startTransaction();
+  system.addConstraint(algNumConstraint);
+  system.prepare();
+  system.solveFine();
+  system.finishTransaction();
+
+  __DEBUG__.AddNormal(face1.csys.origin, new Vector().set3(objects[0].normal.map(p => p.get())))
+  __DEBUG__.AddNormal(face2.csys.origin, new Vector().set3(objects[1].normal.map(p => p.get())))
+
+
+
+  function applyResults(shell, targetCsysParams, normal) {
+    const [
+      ox, oy, oz, ix, iy, iz, jx, jy, jz, kx, ky, kz
+    ] = targetCsysParams.map(p => p.get());
+
+    const targetCsys = new CSys(
+      new Vector(ox, oy, oz),
+      new Vector(ix, iy, iz),
+      new Vector(jx, jy, jz),
+      new Vector(kx, ky, kz),
+    );
+
+    const basis = [
+      new Vector(ix, iy, iz),
+      new Vector(jx, jy, jz),
+      new Vector(kx, ky, kz),
+    ];
+
+    // __DEBUG__.AddCSys(shell.csys);
+    __DEBUG__.AddCSys(targetCsys);
+
+    const tr = shell.csys.inTransformation3x3;
+    basis.forEach(r => tr._apply(r));
+
+    shell.location$.update(csys => {
+      return targetCsys;
+    });
+    // shell.location$.mutate(csys => {
+    //   csys.x = basis[0];
+    //   csys.y = basis[1];
+    //   csys.z = basis[2];
+    //   csys.origin = new Vector(ox, oy, oz)._minus(shell.csys.origin);
+    // });
+
+  }
+
+  applyResults(face1.shell, objects[2].params, new Vector().set3(objects[0].normal.map(p => p.get())));
+  applyResults(face2.shell, objects[3].params, new Vector().set3(objects[1].normal.map(p => p.get())));
+
+
+}
+
+
+function rigidBodyLink3x3(csysParams, csys, vector) {
+  const [ix, iy, iz, jx, jy, jz, kx, ky, kz] = csysParams;
+  const [x, y, z] = vector;
+
+  // const [nStarX, nStarY, nStarZ] = csys.inTransformation3x3.apply3(vector.map(p => p.get()));
+  const [nStarX, nStarY, nStarZ] = vector.map(p => p.get());
+  // out.x = this.mxx * x + this.mxy * y + this.mxz * z + this.tx;
+  // out.y = this.myx * x + this.myy * y + this.myz * z + this.ty;
+  // out.z = this.mzx * x + this.mzy * y + this.mzz * z + this.tz;
+
+  return [
+    new Polynomial(0)
+      .monomial(-1)
+      .term(x, POW_1_FN)
+      .monomial(nStarX)
+      .term(ix, POW_1_FN)
+      .monomial(nStarY)
+      .term(jx, POW_1_FN)
+      .monomial(nStarZ)
+      .term(kx, POW_1_FN),
+
+    new Polynomial(0)
+      .monomial(-1)
+      .term(y, POW_1_FN)
+      .monomial(nStarX)
+      .term(iy, POW_1_FN)
+      .monomial(nStarY)
+      .term(jy, POW_1_FN)
+      .monomial(nStarZ)
+      .term(ky, POW_1_FN),
+
+    new Polynomial(0)
+      .monomial(-1)
+      .term(z, POW_1_FN)
+      .monomial(nStarX)
+      .term(iz, POW_1_FN)
+      .monomial(nStarY)
+      .term(jz, POW_1_FN)
+      .monomial(nStarZ)
+      .term(kz, POW_1_FN),
+
+
+    new Polynomial(0)
+      .monomial()
+        .term(ix, POW_1_FN)
+        .term(jx, POW_1_FN)
+      .monomial()
+        .term(iy, POW_1_FN)
+        .term(jy, POW_1_FN)
+      .monomial()
+        .term(iz, POW_1_FN)
+        .term(jz, POW_1_FN),
+
+    new Polynomial(0)
+      .monomial()
+      .term(ix, POW_1_FN)
+      .term(kx, POW_1_FN)
+      .monomial()
+      .term(iy, POW_1_FN)
+      .term(ky, POW_1_FN)
+      .monomial()
+      .term(iz, POW_1_FN)
+      .term(kz, POW_1_FN),
+
+    new Polynomial(0)
+      .monomial()
+      .term(jx, POW_1_FN)
+      .term(kx, POW_1_FN)
+      .monomial()
+      .term(jy, POW_1_FN)
+      .term(ky, POW_1_FN)
+      .monomial()
+      .term(jz, POW_1_FN)
+      .term(kz, POW_1_FN),
+
+    new Polynomial(-1)
+      .monomial()
+      .term(ix, POW_2_FN)
+      .monomial()
+      .term(iy, POW_2_FN)
+      .monomial()
+      .term(iz, POW_2_FN),
+
+    new Polynomial(-1)
+      .monomial()
+      .term(jx, POW_2_FN)
+      .monomial()
+      .term(jy, POW_2_FN)
+      .monomial()
+      .term(jz, POW_2_FN),
+
+    new Polynomial(-1)
+      .monomial()
+      .term(kx, POW_2_FN)
+      .monomial()
+      .term(ky, POW_2_FN)
+      .monomial()
+      .term(kz, POW_2_FN),
+
+
+  ]
+}
diff --git a/web/app/cad/dom/components/PlugableControlBar.jsx b/web/app/cad/dom/components/PlugableControlBar.jsx
index 5f28f491..34dc58cd 100644
--- a/web/app/cad/dom/components/PlugableControlBar.jsx
+++ b/web/app/cad/dom/components/PlugableControlBar.jsx
@@ -4,7 +4,6 @@ import connect from 'ui/connect';
 import Fa from 'ui/components/Fa';
 import {toIdAndOverrides} from '../../actions/actionRef';
 import {isMenuAction} from '../menu/menuPlugin';
-import {combine} from 'lstream';
 import {menuAboveElementHint} from '../menu/menuUtils';
 import {useStream} from "../../../../../modules/ui/effects";
 import {ActionButtonBehavior} from "../../actions/ActionButtonBehavior";
@@ -44,11 +43,13 @@ const RightGroup = connect(streams => streams.ui.controlBars.right.map(actions =
 function ConnectedActionButton(props) {
 
   const actionId = props.actionId;
-  const stream = useStream(ctx => combine(ctx.streams.action.appearance[actionId], ctx.streams.action.state[actionId]));
-  if (!stream) {
+
+  const actionAppearance = useStream(ctx => ctx.streams.action.appearance[actionId]);
+  const actionState = useStream(ctx => ctx.streams.action.state[actionId]);
+
+  if (!actionAppearance || !actionState) {
     return null;
   }
-  const [actionAppearance, actionState] = stream;
 
   return <ActionButtonBehavior actionId={actionId}>
     {behaviourProps => <ActionButton {...behaviourProps} {...actionAppearance} {...actionState} {...props} />}
diff --git a/web/app/cad/dom/components/PlugableToolbar.jsx b/web/app/cad/dom/components/PlugableToolbar.jsx
index 3c455af9..8cea9664 100644
--- a/web/app/cad/dom/components/PlugableToolbar.jsx
+++ b/web/app/cad/dom/components/PlugableToolbar.jsx
@@ -67,11 +67,11 @@ function ActionButton({label, icon, icon96, icon32, cssIcons, symbol, size, noLa
 export function ConnectedActionButton(props) {
 
   const actionId = props.actionId;
-  const stream = useStream(ctx => combine(ctx.streams.action.appearance[actionId], ctx.streams.action.state[actionId]));
-  if (!stream) {
+  const actionAppearance = useStream(ctx => ctx.streams.action.appearance[actionId]);
+  const actionState = useStream(ctx => ctx.streams.action.state[actionId]);
+  if (!actionAppearance || !actionState) {
     return null;
   }
-  const [actionAppearance, actionState] = stream;
 
   return<ActionButtonBehavior actionId={actionId}>
     {behaviourProps => <ActionButton {...behaviourProps} {...actionAppearance} {...actionState} {...props} />}
diff --git a/web/app/cad/dom/components/UISystem.tsx b/web/app/cad/dom/components/UISystem.tsx
index fc07ab21..59a11ecd 100644
--- a/web/app/cad/dom/components/UISystem.tsx
+++ b/web/app/cad/dom/components/UISystem.tsx
@@ -31,7 +31,6 @@ export default function UISystem({children, ...props}) {
       <MenuHolder/>
       <ActionInfo/>
         {children}
-      <ContributedComponents/>
       <Scope><DocumentationWindow/></Scope>
     </div>
   </UISystemContext.Provider>;
diff --git a/web/app/cad/dom/components/View3d.jsx b/web/app/cad/dom/components/View3d.jsx
index bd2c8e69..d8e80c96 100644
--- a/web/app/cad/dom/components/View3d.jsx
+++ b/web/app/cad/dom/components/View3d.jsx
@@ -19,6 +19,8 @@ import {ConstraintEditor} from "../../../sketcher/components/ConstraintEditor";
 import SketcherOperationWizard from "../../../sketcher/components/SketcherOperationWizard";
 import {ToastContainer} from "react-toastify";
 import 'react-toastify/dist/ReactToastify.css';
+import {ContributedComponents} from "./ContributedComponents";
+import {ModellerContextualActions} from "./ModellerContextualActions";
 
 export default class View3d extends React.Component {
 
@@ -56,6 +58,8 @@ export default class View3d extends React.Component {
             <div className={ls.wizardArea} >
               <WizardManager/>
             </div>
+            <ContributedComponents/>
+            <Scope><ModellerContextualActions /></Scope>
           </div>
 
           <div className={ls.bottomStack}>
diff --git a/web/app/cad/dom/menu/MenuHolder.jsx b/web/app/cad/dom/menu/MenuHolder.jsx
index b4f50c42..1d517cdc 100644
--- a/web/app/cad/dom/menu/MenuHolder.jsx
+++ b/web/app/cad/dom/menu/MenuHolder.jsx
@@ -57,11 +57,14 @@ const ConnectedActionMenu = connect((streams, props) =>
 export function ConnectedMenuItem(props) {
 
   const actionId = props.actionId;
-  const stream = useStream(ctx => combine(ctx.streams.action.appearance[actionId], ctx.streams.action.state[actionId]));
-  if (!stream) {
+
+  const actionAppearance = useStream(ctx => ctx.streams.action.appearance[actionId]);
+  const actionState = useStream(ctx => ctx.streams.action.state[actionId]);
+
+
+  if (!actionAppearance || !actionState) {
     return null;
   }
-  const [actionAppearance, actionState] = stream;
 
   return <ActionButtonBehavior actionId={actionId}>
     {behaviourProps => <ActionMenuItem {...behaviourProps} {...actionAppearance} {...actionState} {...props} />}
diff --git a/web/app/cad/init/startApplication.js b/web/app/cad/init/startApplication.js
index efc2031d..f8524154 100644
--- a/web/app/cad/init/startApplication.js
+++ b/web/app/cad/init/startApplication.js
@@ -36,7 +36,7 @@ import * as UIConfigPlugin from "../part/uiConfigPlugin";
 import * as DebugPlugin from "../debugPlugin";
 import * as ExpressionsPlugin from "../expressions/expressionsPlugin";
 import * as PartOperationsPlugin from "../part/partOperationsPlugin";
-
+import * as LocationPlugin from "../location/locationPlugin";
 
 export default function startApplication(callback) {
 
@@ -75,6 +75,7 @@ export default function startApplication(callback) {
     UIConfigPlugin,
     DebugPlugin,
     PartOperationsPlugin,
+    LocationPlugin,
     RemotePartsPlugin,
     ViewSyncPlugin,
     WizardSelectionPlugin
diff --git a/web/app/cad/legacy/mesh/revolve.js b/web/app/cad/legacy/mesh/revolve.js
index 3feb4560..a0eb7bec 100644
--- a/web/app/cad/legacy/mesh/revolve.js
+++ b/web/app/cad/legacy/mesh/revolve.js
@@ -1,4 +1,4 @@
-import {Matrix3} from '../../../math/l3space'
+import {Matrix3} from '../../../../../modules/math/l3space'
 import Vector from 'math/vector';
 import * as math from '../../../math/math'
 import {createShared} from '../../cad-utils'
diff --git a/web/app/cad/legacy/mesh/wizards/box.js b/web/app/cad/legacy/mesh/wizards/box.js
index e70adc8b..1dec1a03 100644
--- a/web/app/cad/legacy/mesh/wizards/box.js
+++ b/web/app/cad/legacy/mesh/wizards/box.js
@@ -1,4 +1,4 @@
-import {AXIS, IDENTITY_BASIS} from '../../../../math/l3space'
+import {AXIS, IDENTITY_BASIS} from '../../../../../../modules/math/l3space'
 import * as tk from '../../../../ui/toolkit.js'
 import {FACE_COLOR} from '../../../cad-utils'
 import {Wizard} from './wizard-commons'
diff --git a/web/app/cad/legacy/mesh/wizards/extrude.js b/web/app/cad/legacy/mesh/wizards/extrude.js
index 4f41a9d2..79566f34 100644
--- a/web/app/cad/legacy/mesh/wizards/extrude.js
+++ b/web/app/cad/legacy/mesh/wizards/extrude.js
@@ -2,7 +2,7 @@ import * as tk from '../../../../ui/toolkit.js'
 import * as workbench from '../workbench'
 import * as cad_utils from '../../../cad-utils'
 import Vector from 'math/vector';
-import {Matrix3, ORIGIN} from '../../../../math/l3space'
+import {Matrix3, ORIGIN} from '../../../../../../modules/math/l3space'
 import {OpWizard, IMAGINE_MATERIAL, BASE_MATERIAL} from './wizard-commons'
 
 export function ExtrudeWizard(app, face, invert, initParams) {
diff --git a/web/app/cad/legacy/mesh/wizards/plane.js b/web/app/cad/legacy/mesh/wizards/plane.js
index 31416e93..3fad1d3a 100644
--- a/web/app/cad/legacy/mesh/wizards/plane.js
+++ b/web/app/cad/legacy/mesh/wizards/plane.js
@@ -1,8 +1,8 @@
-import {AXIS, IDENTITY_BASIS} from '../../../../math/l3space'
+import {AXIS, IDENTITY_BASIS} from '../../../../../../modules/math/l3space'
 import * as tk from '../../../../ui/toolkit.js'
 import {FACE_COLOR} from '../../../cad-utils'
 import {Wizard} from './wizard-commons'
-import {Matrix3} from '../../../../math/l3space'
+import {Matrix3} from '../../../../../../modules/math/l3space'
 
 export function PlaneWizard(app, initParams) {
   Wizard.call(this, app.viewer, initParams);
diff --git a/web/app/cad/legacy/mesh/wizards/revolve.js b/web/app/cad/legacy/mesh/wizards/revolve.js
index 8ac52aff..dc1097e8 100644
--- a/web/app/cad/legacy/mesh/wizards/revolve.js
+++ b/web/app/cad/legacy/mesh/wizards/revolve.js
@@ -2,7 +2,7 @@ import * as tk from '../../../../ui/toolkit.js'
 import * as workbench from '../workbench'
 import * as cad_utils from '../../../cad-utils'
 import Vector from 'math/vector';
-import {Matrix3, ORIGIN} from '../../../../math/l3space'
+import {Matrix3, ORIGIN} from '../../../../../../modules/math/l3space'
 import {revolveToTriangles} from '../revolve'
 import {OpWizard, IMAGINARY_SURFACE_MATERIAL, } from './wizard-commons'
 
diff --git a/web/app/cad/legacy/mesh/wizards/sphere.js b/web/app/cad/legacy/mesh/wizards/sphere.js
index f1a7e998..2e263a67 100644
--- a/web/app/cad/legacy/mesh/wizards/sphere.js
+++ b/web/app/cad/legacy/mesh/wizards/sphere.js
@@ -1,4 +1,4 @@
-import {AXIS, IDENTITY_BASIS} from '../../../../math/l3space'
+import {AXIS, IDENTITY_BASIS} from '../../../../../../modules/math/l3space'
 import * as tk from '../../../../ui/toolkit.js'
 import {FACE_COLOR} from '../../../cad-utils'
 import {Wizard} from './wizard-commons'
diff --git a/web/app/cad/legacy/mesh/wizards/transform.js b/web/app/cad/legacy/mesh/wizards/transform.js
index 4d89caf9..c7404197 100644
--- a/web/app/cad/legacy/mesh/wizards/transform.js
+++ b/web/app/cad/legacy/mesh/wizards/transform.js
@@ -1,4 +1,4 @@
-import {AXIS, IDENTITY_BASIS} from '../../../../math/l3space'
+import {AXIS, IDENTITY_BASIS} from '../../../../../../modules/math/l3space'
 import * as tk from '../../../../ui/toolkit.js'
 import {FACE_COLOR} from '../../../cad-utils'
 import {Wizard} from './wizard-commons'
diff --git a/web/app/cad/location/LocationDialog.tsx b/web/app/cad/location/LocationDialog.tsx
new file mode 100644
index 00000000..5cdcd023
--- /dev/null
+++ b/web/app/cad/location/LocationDialog.tsx
@@ -0,0 +1,116 @@
+import React, {useCallback, useContext} from 'react';
+import {useStreamWithUpdater} from "ui/effects";
+import {AppContext} from "../dom/components/AppContext";
+import {GenericWizard} from "ui/components/GenericWizard";
+import Field from "ui/components/controls/Field";
+import {Group} from "../craft/wizard/components/form/Form";
+import Label from "ui/components/controls/Label";
+import Folder from "ui/components/Folder";
+import {never} from "lstream";
+import NumberControl from "ui/components/controls/NumberControl";
+import {Location} from "../model/location";
+import {DEG_RAD} from "../../math/math";
+import CSys from "math/csys";
+
+export function LocationDialog() {
+
+  const [req, setReq] = useStreamWithUpdater(ctx => ctx.locationService.editLocationRequest$);
+
+
+  const [location, setLocation] = useStreamWithUpdater(() => req ? req.shell.location$ : never<CSys>());
+
+  const setX = useCallback(x => {
+    location.origin.x = parseFloat(x);
+    setLocation(location);
+  }, [setLocation]);
+
+  const setY = useCallback(y => {
+    location.origin.y = parseFloat(y);
+    setLocation(location);
+  }, [setLocation]);
+
+  const setZ = useCallback(z => {
+    location.origin.z = parseFloat(z);
+    setLocation(location);
+  }, [setLocation]);
+  //
+  // const setAzimuth = useCallback(angle => {
+  //   location.rotationAxisAzimuth = parseFloat(angle) * DEG_RAD;
+  //   setLocation(location);
+  // }, [setLocation]);
+  //
+  // const setInclination = useCallback(angle => {
+  //   location.rotationAxisInclination = parseFloat(angle) * DEG_RAD;
+  //   setLocation(location);
+  // }, [setLocation]);
+  //
+  // const setAngle = useCallback(angle => {
+  //   location.rotationAxisAngle = parseFloat(angle) * DEG_RAD;
+  //   setLocation(location);
+  // }, [setLocation]);
+
+  const ctx = useContext(AppContext);
+
+  if (!req) {
+    return null;
+  }
+
+  const revert = () => {
+    // close();
+  };
+
+  const close = () => {
+    setReq(null);
+  };
+
+  const revertAndClose = () => {
+    close();
+  };
+
+  return <GenericWizard
+    left={15}
+    title='PART LOCATION'
+    onClose={close}
+    className='location-dialog'
+    topicId='entity-location'
+    infoText={null}
+    onCancel={revertAndClose}
+    onOK={close} >
+
+    <Folder title='Position'>
+      <Group>
+        <Field active={false} name='X'>
+          <Label>X:</Label>
+          <NumberControl onChange={setX} value={location.origin.x} />
+        </Field>
+        <Field active={false} name='Y'>
+          <Label>Y:</Label>
+          <NumberControl onChange={setY} value={location.origin.y} />
+        </Field>
+        <Field active={false} name='Z'>
+          <Label>Z:</Label>
+          <NumberControl onChange={setZ} value={location.origin.z} />
+        </Field>
+      </Group>
+    </Folder>
+    <Folder title='Rotation'>
+      <Group>
+        {/*<Field active={false} name='Azimuth'>*/}
+        {/*  <Label>Axis Azimuth:</Label>*/}
+        {/*  <NumberControl onChange={setAzimuth} value={location.rotationAxisAzimuth / DEG_RAD} />*/}
+        {/*</Field>*/}
+        {/*<Field active={false} name='Inclination'>*/}
+        {/*  <Label>Axis Inclination:</Label>*/}
+        {/*  <NumberControl onChange={setInclination} value={location.rotationAxisInclination / DEG_RAD} />*/}
+        {/*</Field>*/}
+        {/*<Field active={false} name='Angle'>*/}
+        {/*  <Label>Angle:</Label>*/}
+        {/*  <NumberControl onChange={setAngle} value={location.rotationAxisAngle / DEG_RAD} />*/}
+        {/*</Field>*/}
+      </Group>
+    </Folder>
+
+
+  </GenericWizard>
+
+}
\ No newline at end of file
diff --git a/web/app/cad/location/LocationPlugin.ts b/web/app/cad/location/LocationPlugin.ts
new file mode 100644
index 00000000..14b6f285
--- /dev/null
+++ b/web/app/cad/location/LocationPlugin.ts
@@ -0,0 +1,44 @@
+import {state, StateStream} from "lstream";
+import {ApplicationContext} from "context";
+import {MShell} from "../model/mshell";
+import {LocationDialog} from "./LocationDialog";
+
+export function activate(ctx: ApplicationContext) {
+
+  ctx.domService.contributeComponent(LocationDialog);
+
+  const editLocationRequest$ = state(null);
+
+  ctx.locationService = {
+    editLocationRequest$,
+
+    edit: shell => {
+      editLocationRequest$.next({
+        shell
+      })
+    }
+  };
+}
+
+
+export interface EditLocationRequest {
+
+  shell: MShell;
+
+}
+
+export interface LocationService {
+
+  editLocationRequest$: StateStream<EditLocationRequest>;
+
+  edit(shell);
+
+}
+
+declare module 'context' {
+  interface ApplicationContext {
+
+    locationService: LocationService;
+  }
+}
+
diff --git a/web/app/cad/model/location.ts b/web/app/cad/model/location.ts
new file mode 100644
index 00000000..7565d7ca
--- /dev/null
+++ b/web/app/cad/model/location.ts
@@ -0,0 +1,24 @@
+import Vector from "math/vector";
+import {Matrix3} from "math/l3space";
+
+export class Location {
+
+  rotationAxisAzimuth: number = 0;
+  rotationAxisInclination: number = 0;
+  rotationAxisAngle: number = 0;
+
+  translation: Vector = new Vector();
+
+  __mx = new Matrix3();
+
+  toTransformationMatrix() {
+    this.__mx.rotateWithSphericalAxis(
+      this.rotationAxisAzimuth,
+      this.rotationAxisInclination,
+      this.rotationAxisAngle,
+      this.translation
+    );
+    return this.__mx;
+  }
+
+}
\ No newline at end of file
diff --git a/web/app/cad/model/mdatum.ts b/web/app/cad/model/mdatum.ts
index 43be347f..72245511 100644
--- a/web/app/cad/model/mdatum.ts
+++ b/web/app/cad/model/mdatum.ts
@@ -1,5 +1,5 @@
 import {MObject, MObjectIdGenerator} from './mobject';
-import CSys from "../../math/csys";
+import CSys from "math/csys";
 import Vector from "math/vector";
 
 export class MDatum extends MObject {
@@ -13,9 +13,9 @@ export class MDatum extends MObject {
   constructor(csys) {
     super(MDatum.TYPE, MObjectIdGenerator.next(MDatum.TYPE, 'D'));
     this.csys = csys;
-    this.xAxis = new MDatumAxis(this.id + '/X', this.csys.origin, this.csys.x);
-    this.yAxis = new MDatumAxis(this.id + '/Y', this.csys.origin, this.csys.y);
-    this.zAxis = new MDatumAxis(this.id + '/Z', this.csys.origin, this.csys.z);
+    this.xAxis = new MDatumAxis(this.id + '/X', this.csys.origin, this.csys.x, this);
+    this.yAxis = new MDatumAxis(this.id + '/Y', this.csys.origin, this.csys.y, this);
+    this.zAxis = new MDatumAxis(this.id + '/Z', this.csys.origin, this.csys.z, this);
   }
 
   getAxisByLiteral(literal) {
@@ -33,6 +33,10 @@ export class MDatum extends MObject {
     this.yAxis.traverse(callback);
     this.zAxis.traverse(callback);
   }
+
+  get parent() {
+    return null;
+  }
 }
 
 export class MDatumAxis extends MObject {
@@ -40,10 +44,16 @@ export class MDatumAxis extends MObject {
   static TYPE = 'datumAxis';
   origin: Vector;
   dir: Vector;
+  holder: MObject;
 
-  constructor(id, origin, dir) {
+  constructor(id, origin, dir, holder) {
     super(MDatumAxis.TYPE, id);
     this.origin = origin;
     this.dir = dir;
+    this.holder = holder;
+  }
+
+  get parent() {
+    return this.holder;
   }
 }
\ No newline at end of file
diff --git a/web/app/cad/model/medge.ts b/web/app/cad/model/medge.ts
index d995a6fe..b2fa0dcf 100644
--- a/web/app/cad/model/medge.ts
+++ b/web/app/cad/model/medge.ts
@@ -1,5 +1,5 @@
 import {MObject} from './mobject';
-import {MBrepShell, MShell} from "./mshell";
+import {MBrepShell} from "./mshell";
 
 export class MEdge extends MObject {
 
@@ -25,4 +25,8 @@ export class MEdge extends MObject {
     }
     return out;
   }
+
+  get parent() {
+    return this.shell;
+  }
 }
\ No newline at end of file
diff --git a/web/app/cad/model/mface.ts b/web/app/cad/model/mface.ts
index 319b9bde..fc9bb0c4 100644
--- a/web/app/cad/model/mface.ts
+++ b/web/app/cad/model/mface.ts
@@ -1,12 +1,13 @@
 import {MObject} from './mobject';
 import Vector from 'math/vector';
-import {BasisForPlane} from '../../math/l3space';
+import {BasisForPlane} from 'math/l3space';
 import {MSketchObject} from './msketchObject';
 import {EMPTY_ARRAY} from 'gems/iterables';
-import CSys from '../../math/csys';
+import CSys from 'math/csys';
 import {MSketchLoop} from './mloop';
 import {ProductionInfo} from './productionInfo';
 import {MBrepShell, MShell} from "./mshell";
+import {AssemblyUnitVectorNode} from "../assembly/assembly";
 
 export class MFace extends MObject {
 
@@ -18,6 +19,10 @@ export class MFace extends MObject {
   sketch: any;
   brepFace: any;
 
+  assemblyNodes: {
+    normal: AssemblyUnitVectorNode
+  };
+
   private _csys: any;
   private w: number;
   private _basis: [Vector, Vector, Vector];
@@ -31,7 +36,10 @@ export class MFace extends MObject {
     this.surface = surface;
     this.sketchObjects = [];
     this.sketchLoops = [];
-    this._csys = csys
+    this._csys = csys;
+    this.assemblyNodes = {
+      normal: new AssemblyUnitVectorNode(this, () => this.normal())
+    };
   }
 
   normal() {
@@ -166,6 +174,10 @@ export class MFace extends MObject {
     this.sketchLoops.forEach(i => i.traverse(callback));
   }
 
+  get parent() {
+    return this.shell;
+  }
+
 }
 
 export class MBrepFace extends MFace {
diff --git a/web/app/cad/model/mloop.ts b/web/app/cad/model/mloop.ts
index 5ab92b18..3f6ce612 100644
--- a/web/app/cad/model/mloop.ts
+++ b/web/app/cad/model/mloop.ts
@@ -10,6 +10,9 @@ export class MLoop extends MObject {
     super(MLoop.TYPE, id);
   }
 
+  get parent() {
+    return null;
+  }
 }
 
 export class MSketchLoop extends MLoop {
@@ -24,5 +27,9 @@ export class MSketchLoop extends MLoop {
     this.contour = contour;
   }
 
+  get parent() {
+    return this.face;
+  }
+
 }
 
diff --git a/web/app/cad/model/mobject.ts b/web/app/cad/model/mobject.ts
index f60655fd..f2ba9493 100644
--- a/web/app/cad/model/mobject.ts
+++ b/web/app/cad/model/mobject.ts
@@ -1,11 +1,10 @@
-
 export abstract class MObject {
 
   TYPE: string;
   
   id: string;
   ext: any = {};
- 
+
   constructor(TYPE, id) {
     this.TYPE = TYPE;
     this.id = id;
@@ -14,6 +13,16 @@ export abstract class MObject {
   traverse(callback: (obj: MObject) => void): void {
     callback(this);
   }
+
+  abstract get parent();
+
+  get root(): MObject {
+    let obj = this;
+    while (obj.parent) {
+      obj = obj.parent;
+    }
+    return obj;
+  }
 }
 
 export const MObjectIdGenerator = {
@@ -50,3 +59,4 @@ export const MObjectIdGenerator = {
   }
 
 };
+
diff --git a/web/app/cad/model/mopenFace.ts b/web/app/cad/model/mopenFace.ts
index f5da3404..3961630e 100644
--- a/web/app/cad/model/mopenFace.ts
+++ b/web/app/cad/model/mopenFace.ts
@@ -16,5 +16,8 @@ export class MOpenFaceShell extends MShell {
   get face() {
     return this.faces[0];
   }
-  
+
+  get parent() {
+    return null;
+  }
 }
diff --git a/web/app/cad/model/mshell.ts b/web/app/cad/model/mshell.ts
index c9e9c5fe..76362c9c 100644
--- a/web/app/cad/model/mshell.ts
+++ b/web/app/cad/model/mshell.ts
@@ -1,8 +1,11 @@
 import {MObject, MObjectIdGenerator} from './mobject';
-import {MBrepFace, MFace} from './mface';
+import {MBrepFace} from './mface';
 import {MEdge} from './medge';
 import {MVertex} from './mvertex';
-import CSys from '../../math/csys';
+import CSys from 'math/csys';
+import {Matrix3} from "math/l3space";
+import {state, StateStream} from "lstream";
+import {AssemblyCSysNode} from "../assembly/assembly";
 
 export class MShell extends MObject {
 
@@ -15,8 +18,20 @@ export class MShell extends MObject {
   edges = [];
   vertices = [];
 
+  location$: StateStream<CSys> = state(CSys.origin());
+  locationMatrix$ = this.location$.map((csys: CSys) => csys.outTransformation).remember();
+
+  assemblyNodes: {
+    location: AssemblyCSysNode
+  };
+
   constructor() {
-    super(MShell.TYPE, MObjectIdGenerator.next(MShell.TYPE, 'S'))
+    super(MShell.TYPE, MObjectIdGenerator.next(MShell.TYPE, 'S'));
+    // @ts-ignore
+    this.assemblyNodes = {
+      location: new AssemblyCSysNode( this, () => new Matrix3() )
+    };
+
   }
 
   traverse(callback: (obj: MObject) => void): void {
@@ -25,6 +40,10 @@ export class MShell extends MObject {
     this.edges.forEach(i => i.traverse(callback));
     this.vertices.forEach(i => i.traverse(callback));
   }
+
+  get parent() {
+    return null;
+  }
 }
 
 export class MBrepShell extends MShell {
diff --git a/web/app/cad/model/msketchObject.ts b/web/app/cad/model/msketchObject.ts
index c5ba0444..8578f708 100644
--- a/web/app/cad/model/msketchObject.ts
+++ b/web/app/cad/model/msketchObject.ts
@@ -15,4 +15,8 @@ export class MSketchObject extends MObject {
     this.construction = false;
   }
 
+  get parent() {
+    return this.face;
+  }
+
 }
\ No newline at end of file
diff --git a/web/app/cad/model/mvertex.ts b/web/app/cad/model/mvertex.ts
index fafce99a..25a56317 100644
--- a/web/app/cad/model/mvertex.ts
+++ b/web/app/cad/model/mvertex.ts
@@ -13,4 +13,8 @@ export class MVertex extends MObject {
     this.brepVertex = brepVertex;
   }
 
+  get parent() {
+    return this.shell;
+  }
+
 }
\ No newline at end of file
diff --git a/web/app/cad/part/uiConfigPlugin.js b/web/app/cad/part/uiConfigPlugin.js
index db7518ce..6371d5a5 100644
--- a/web/app/cad/part/uiConfigPlugin.js
+++ b/web/app/cad/part/uiConfigPlugin.js
@@ -11,7 +11,7 @@ import {SelectionView} from "../dom/components/SelectionView";
 import {GrSelect} from "react-icons/gr";
 
 export const STANDARD_MODE_HEADS_UP_TOOLBAR = ['DATUM_CREATE', 'PLANE', 'EditFace', 'EXTRUDE', 'CUT', 'REVOLVE', 'LOFT',
-  '-', 'FILLET', '-', 'INTERSECTION', 'SUBTRACT', 'UNION', '-', 'IMPORT_PART'];
+  '-', 'FILLET', '-', 'INTERSECTION', 'SUBTRACT', 'UNION', '-', 'IMPORT_PART', "IMPORT_STEP_FILE"];
 
 export function activate({services, streams}) {
   streams.ui.controlBars.left.value = ['menu.file', 'menu.craft', 'menu.boolean', 'menu.primitives', 'menu.views', 'Donate', 'GitHub'];
diff --git a/web/app/cad/sandbox.js b/web/app/cad/sandbox.js
index 4af12548..82d96bfd 100644
--- a/web/app/cad/sandbox.js
+++ b/web/app/cad/sandbox.js
@@ -1,4 +1,4 @@
-import {AXIS, Matrix3, ORIGIN} from '../math/l3space'
+import {AXIS, Matrix3, ORIGIN} from '../../../modules/math/l3space'
 import * as vec from 'math/vec'
 import Vector from 'math/vector';
 import BrepBuilder from '../brep/brep-builder'
@@ -9,7 +9,7 @@ import {surfaceIntersect} from '../brep/geom/intersection/surfaceSurface';
 import {closestToCurveParam} from '../brep/geom/curves/closestPoint';
 import NurbsSurface from '../brep/geom/surfaces/nurbsSurface';
 import DatumObject3D from './craft/datum/datumObject';
-import CSys from '../math/csys';
+import CSys from '../../../modules/math/csys';
 import {createOctreeFromSurface, sphereOctree, traverseOctree} from "../../../modules/voxels/octree";
 
 export function runSandbox({bus, services, services: { viewer, cadScene, cadRegistry, exposure, exposure: {addShellOnScene} }}) {
diff --git a/web/app/cad/scene/cadScene.js b/web/app/cad/scene/cadScene.js
index 3e612f86..41308eb0 100644
--- a/web/app/cad/scene/cadScene.js
+++ b/web/app/cad/scene/cadScene.js
@@ -1,4 +1,4 @@
-import {AXIS} from '../../math/l3space'
+import {AXIS} from '../../../../modules/math/l3space'
 import {createArrow} from 'scene/objects/auxiliary';
 import Vector from 'math/vector';
 import {OnTopOfAll} from 'scene/materialMixins';
diff --git a/web/app/cad/scene/controls/pickControlPlugin.js b/web/app/cad/scene/controls/pickControlPlugin.js
index ff906568..6dce7d86 100644
--- a/web/app/cad/scene/controls/pickControlPlugin.js
+++ b/web/app/cad/scene/controls/pickControlPlugin.js
@@ -69,6 +69,7 @@ export function activate(context) {
   
   domElement.addEventListener('mousedown', mousedown, false);
   domElement.addEventListener('mouseup', mouseup, false);
+  domElement.addEventListener('dblclick', mousedblclick, false);
 
   let mouseState = {
     startX: 0,
@@ -93,6 +94,10 @@ export function activate(context) {
     }
   }
 
+  function mousedblclick(e) {
+    handleSolidPick(e);
+  }
+
   function setPickHandler(handler) {
     pickHandler = handler || defaultHandler;
     services.marker.clear();
@@ -136,8 +141,7 @@ export function activate(context) {
   function handleSolidPick(e) {
     let pickResults = services.viewer.raycast(e, services.cadScene.workGroup.children);
     traversePickResults(e, pickResults, PICK_KIND.FACE, (sketchFace) => {
-      streams.selection.solid.next([sketchFace.solid]);
-      services.viewer.render();
+      context.locationService.edit(sketchFace.shell);
       return false;
     });
   }
diff --git a/web/app/cad/scene/viewSyncPlugin.js b/web/app/cad/scene/viewSyncPlugin.js
index 1f03896c..ec9699c6 100644
--- a/web/app/cad/scene/viewSyncPlugin.js
+++ b/web/app/cad/scene/viewSyncPlugin.js
@@ -38,7 +38,7 @@ function sceneSynchronizer({services: {cadScene, cadRegistry, viewer, wizard, ac
         if (model instanceof MOpenFaceShell) {
           modelView = new OpenFaceShellView(model);
         } else if (model instanceof MShell) {
-          modelView = new ShellView(model);
+          modelView = new ShellView(model, undefined, viewer);
         } else if (model instanceof MDatum) {
           modelView = new DatumView(model, viewer, 
             wizard.open,
diff --git a/web/app/cad/scene/views/shellView.js b/web/app/cad/scene/views/shellView.js
index f6ddf181..356f8d49 100644
--- a/web/app/cad/scene/views/shellView.js
+++ b/web/app/cad/scene/views/shellView.js
@@ -9,7 +9,7 @@ import {Mesh} from 'three';
 
 export class ShellView extends View {
 
-  constructor(shell, skin) {
+  constructor(shell, skin, viewer) {
     super(shell);
 
     this.material = createSolidMaterial(skin);
@@ -45,6 +45,15 @@ export class ShellView extends View {
       SceneGraph.addToGroup(this.edgeGroup, edgeView.rootGroup);
       this.edgeViews.push(edgeView);
     }
+
+    this.rootGroup.matrixAutoUpdate = false;
+
+    this.model.locationMatrix$.attach(loc => {
+      loc.setToMatrix(this.rootGroup.matrix);
+      this.rootGroup.matrixWorldNeedsUpdate = true;
+      viewer.requestRender();
+    });
+
   }
 
   mark(color) {
diff --git a/web/app/cad/scene/wrappers/entityIO.js b/web/app/cad/scene/wrappers/entityIO.js
index 314e1d9d..8ac37f4c 100644
--- a/web/app/cad/scene/wrappers/entityIO.js
+++ b/web/app/cad/scene/wrappers/entityIO.js
@@ -1,6 +1,6 @@
 import {readBrep} from '../../../brep/io/brepIO';
 import {MBrepShell} from '../../model/mshell';
-import CSys from '../../../math/csys';
+import CSys from '../../../../../modules/math/csys';
 
 export function readShellEntityFromJson(data, consumed, csys) {
   
diff --git a/web/app/cad/scene/wrappers/sceneObject.js b/web/app/cad/scene/wrappers/sceneObject.js
index cb43c8e2..d74d8303 100644
--- a/web/app/cad/scene/wrappers/sceneObject.js
+++ b/web/app/cad/scene/wrappers/sceneObject.js
@@ -1,5 +1,5 @@
 import Vector from 'math/vector';
-import {BasisForPlane} from '../../../math/l3space'
+import {BasisForPlane} from '../../../../../modules/math/l3space'
 import DPR from 'dpr'
 import {setAttribute} from "scene/objectData";
 import {genSolidId} from "../../craft/cadRegistryPlugin";
diff --git a/web/app/cad/sketch/inPlaceSketcher.js b/web/app/cad/sketch/inPlaceSketcher.js
index 1cf9a87e..c62fd4e5 100644
--- a/web/app/cad/sketch/inPlaceSketcher.js
+++ b/web/app/cad/sketch/inPlaceSketcher.js
@@ -1,6 +1,6 @@
 import {DelegatingPanTool} from '../../sketcher/tools/pan';
 import {Matrix4} from 'three/src/math/Matrix4';
-import {ORIGIN} from '../../math/l3space';
+import {ORIGIN} from '../../../../modules/math/l3space';
 import {CAMERA_MODE} from '../scene/viewer';
 import DPR from 'dpr';
 import {SKETCHER_MODE_HEADS_UP_ACTIONS} from "./sketcherUIContrib";
diff --git a/web/app/cad/sketch/sketchModel.js b/web/app/cad/sketch/sketchModel.js
index fc59b8cc..051ddb56 100644
--- a/web/app/cad/sketch/sketchModel.js
+++ b/web/app/cad/sketch/sketchModel.js
@@ -6,7 +6,7 @@ import {LUT} from '../../math/bezier-cubic'
 import {distanceAB, isCCW, makeAngle0_360} from '../../math/math'
 import {normalizeCurveEnds} from '../../brep/geom/impl/nurbs-ext';
 import Vector from '../../../../modules/math/vector';
-import {AXIS, ORIGIN} from '../../math/l3space';
+import {AXIS, ORIGIN} from '../../../../modules/math/l3space';
 
 const RESOLUTION = 20;
 
diff --git a/web/app/cad/sketch/sketchReader.js b/web/app/cad/sketch/sketchReader.js
index 4682f8da..45db93da 100644
--- a/web/app/cad/sketch/sketchReader.js
+++ b/web/app/cad/sketch/sketchReader.js
@@ -1,5 +1,5 @@
 import * as sm from './sketchModel'
-import {Matrix3, AXIS, ORIGIN} from '../../math/l3space'
+import {Matrix3, AXIS, ORIGIN} from '../../../../modules/math/l3space'
 import Vector from 'math/vector';
 import {Graph} from '../../math/graph'
 import * as math from '../../math/math'
diff --git a/web/app/math/l3space.js b/web/app/math/l3space.js
deleted file mode 100644
index 78e20e1e..00000000
--- a/web/app/math/l3space.js
+++ /dev/null
@@ -1,277 +0,0 @@
-import Vector from 'math/vector';
-
-const freeze = Object.freeze;
-
-const ORIGIN = freeze(new Vector(0, 0, 0));
-
-const AXIS = freeze({
-  X : freeze(new Vector(1, 0, 0)),
-  Y : freeze(new Vector(0, 1, 0)),
-  Z : freeze(new Vector(0, 0, 1))
-});
-
-const IDENTITY_BASIS = Object.freeze([AXIS.X, AXIS.Y, AXIS.Z]);
-
-export const STANDARD_BASES = freeze({
-  'XY': IDENTITY_BASIS,
-  'XZ': [AXIS.X, AXIS.Z, AXIS.Y],
-  'ZY': [AXIS.Z, AXIS.Y, AXIS.X]
-});
-
-
-class Matrix3 {
-  constructor() {
-    this.reset();
-  }
-
-  apply = vector => this.__apply(vector, new Vector());
-}
-
-Matrix3.prototype.reset = function() {
-  this.mxx = 1; this.mxy = 0; this.mxz = 0; this.tx = 0;
-  this.myx = 0; this.myy = 1; this.myz = 0; this.ty = 0;
-  this.mzx = 0; this.mzy = 0; this.mzz = 1; this.tz = 0;
-  return this;
-};
-
-Matrix3.prototype.setBasis = function(basis) {
-  var b = basis;
-  this.mxx = b[0].x; this.mxy = b[1].x; this.mxz = b[2].x; this.tx = 0;
-  this.myx = b[0].y; this.myy = b[1].y; this.myz = b[2].y; this.ty = 0;
-  this.mzx = b[0].z; this.mzy = b[1].z; this.mzz = b[2].z; this.tz = 0;
-  return this;
-};
-
-Matrix3.prototype.setBasisAxises = function(x, y, z) {
-  this.mxx = x.x; this.mxy = y.x; this.mxz = z.x; this.tx = 0;
-  this.myx = x.y; this.myy = y.y; this.myz = z.y; this.ty = 0;
-  this.mzx = x.z; this.mzy = y.z; this.mzz = z.z; this.tz = 0;
-  return this;
-};
-
-Matrix3.prototype.scale = function(dx, dy, dz) {
-  this.mxx *= dx;
-  this.myy *= dy;
-  this.mzz *= dz;
-  return this;
-};
-
-Matrix3.prototype.translate = function(dx, dy, dz) {
-  this.tx += dx;
-  this.ty += dy;
-  this.tz += dz;
-  return this;
-};
-
-Matrix3.prototype.set3 = function(
-  mxx, mxy, mxz,
-  myx, myy, myz,
-  mzx, mzy, mzz
-) {
-  this.mxx = mxx; this.mxy = mxy; this.mxz = mxz;
-  this.myx = myx; this.myy = myy; this.myz = myz;
-  this.mzx = mzx; this.mzy = mzy; this.mzz = mzz;
-  return this;
-};
-
-Matrix3.prototype.set34 = function(
-  mxx, mxy, mxz, tx,
-  myx, myy, myz, ty,
-  mzx, mzy, mzz, tz
-) {
-  this.mxx = mxx; this.mxy = mxy; this.mxz = mxz; this.tx = tx;
-  this.myx = myx; this.myy = myy; this.myz = myz; this.ty = ty;
-  this.mzx = mzx; this.mzy = mzy; this.mzz = mzz; this.tz = tz;
-  return this;
-};
-
-Matrix3.prototype.setMatrix = function(m) {
-  this.mxx = m.mxx; this.mxy = m.mxy; this.mxz = m.mxz; this.tx = m.tx;
-  this.myx = m.myx; this.myy = m.myy; this.myz = m.myz; this.ty = m.ty;
-  this.mzx = m.mzx; this.mzy = m.mzy; this.mzz = m.mzz; this.tz = m.tz;
-  return this;
-};
-
-Matrix3.prototype.toArray = function() {
-  return [
-    [this.mxx, this.mxy, this.mxz, this.tx],
-    [this.myx, this.myy, this.myz, this.ty],
-    [this.mzx, this.mzy, this.mzz, this.tz]
-  ];
-};
-
-Matrix3.prototype.invert = function() {
-  return this.__invert(new Matrix3());
-};
-
-Matrix3.prototype._invert = function() {
-  return this.__invert(this);
-};
-
-Matrix3.prototype.__invert = function(out) {
-
-  var det =
-    this.mxx * (this.myy * this.mzz - this.mzy * this.myz) +
-    this.mxy * (this.myz * this.mzx - this.mzz * this.myx) +
-    this.mxz * (this.myx * this.mzy - this.mzx * this.myy);
-
-  if (det == 0.0) {
-    return null;
-  }
-
-  var cxx =   this.myy * this.mzz - this.myz * this.mzy;
-  var cyx = - this.myx * this.mzz + this.myz * this.mzx;
-  var czx =   this.myx * this.mzy - this.myy * this.mzx;
-  var cxt = - this.mxy * (this.myz * this.tz - this.mzz  * this.ty)
-    - this.mxz * (this.ty  * this.mzy - this.tz  * this.myy)
-    - this.tx  * (this.myy * this.mzz - this.mzy * this.myz);
-  var cxy = - this.mxy * this.mzz + this.mxz * this.mzy;
-  var cyy =   this.mxx * this.mzz - this.mxz * this.mzx;
-  var czy = - this.mxx * this.mzy + this.mxy * this.mzx;
-  var cyt =   this.mxx * (this.myz * this.tz  - this.mzz * this.ty)
-    + this.mxz * (this.ty  * this.mzx - this.tz  * this.myx)
-    + this.tx  * (this.myx * this.mzz - this.mzx * this.myz);
-  var cxz =   this.mxy * this.myz - this.mxz * this.myy;
-  var cyz = - this.mxx * this.myz + this.mxz * this.myx;
-  var czz =   this.mxx * this.myy - this.mxy * this.myx;
-  var czt = - this.mxx * (this.myy * this.tz - this.mzy  * this.ty)
-    - this.mxy * (this.ty  * this.mzx - this.tz  * this.myx)
-    - this.tx  * (this.myx * this.mzy - this.mzx * this.myy);
-
-  out.mxx = cxx / det;
-  out.mxy = cxy / det;
-  out.mxz = cxz / det;
-  out.tx = cxt / det;
-  out.myx = cyx / det;
-  out.myy = cyy / det;
-  out.myz = cyz / det;
-  out.ty = cyt / det;
-  out.mzx = czx / det;
-  out.mzy = czy / det;
-  out.mzz = czz / det;
-  out.tz = czt / det;
-  return out;
-};
-
-Matrix3.prototype.combine = function(transform, out) {
-  var txx = transform.mxx;
-  var txy = transform.mxy;
-  var txz = transform.mxz;
-  var ttx = transform.tx;
-  var tyx = transform.myx;
-  var tyy = transform.myy;
-  var tyz = transform.myz;
-  var tty = transform.ty;
-  var tzx = transform.mzx;
-  var tzy = transform.mzy;
-  var tzz = transform.mzz;
-  var ttz = transform.tz;
-
-  var m = out || new Matrix3();
-  m.mxx = (this.mxx * txx + this.mxy * tyx + this.mxz * tzx);
-  m.mxy = (this.mxx * txy + this.mxy * tyy + this.mxz * tzy);
-  m.mxz = (this.mxx * txz + this.mxy * tyz + this.mxz * tzz);
-  m.tx  = (this.mxx * ttx + this.mxy * tty + this.mxz * ttz + this.tx);
-  m.myx = (this.myx * txx + this.myy * tyx + this.myz * tzx);
-  m.myy = (this.myx * txy + this.myy * tyy + this.myz * tzy);
-  m.myz = (this.myx * txz + this.myy * tyz + this.myz * tzz);
-  m.ty  = (this.myx * ttx + this.myy * tty + this.myz * ttz + this.ty);
-  m.mzx = (this.mzx * txx + this.mzy * tyx + this.mzz * tzx);
-  m.mzy = (this.mzx * txy + this.mzy * tyy + this.mzz * tzy);
-  m.mzz = (this.mzx * txz + this.mzy * tyz + this.mzz * tzz);
-  m.tz  = (this.mzx * ttx + this.mzy * tty + this.mzz * ttz + this.tz);
-
-  return m;
-};
-
-Matrix3.prototype._apply = function(vector) {
-  return this.__apply(vector, vector);
-};
-
-Matrix3.prototype.__apply = function(vector, out) {
-  let x = vector.x;
-  let y = vector.y;
-  let z = vector.z;
-  out.x = this.mxx * x + this.mxy * y + this.mxz * z + this.tx;
-  out.y = this.myx * x + this.myy * y + this.myz * z + this.ty;
-  out.z = this.mzx * x + this.mzy * y + this.mzz * z + this.tz;
-  return out;
-};
-
-Matrix3.prototype.apply3 = function(data) {
-  return this.__apply3(data, [])
-};
-
-Matrix3.prototype._apply3 = function(data) {
-  return this.__apply3(data, data);
-};
-
-Matrix3.prototype.__apply3 = function([x, y, z], out) {
-  out[0] = this.mxx * x + this.mxy * y + this.mxz * z + this.tx;
-  out[1] = this.myx * x + this.myy * y + this.myz * z + this.ty; 
-  out[2] = this.mzx * x + this.mzy * y + this.mzz * z + this.tz;
-  return out;
-};
-
-Matrix3.prototype.rotate = function(angle, axis, pivot) {
-  return Matrix3.rotateMatrix(angle, axis, pivot, this);  
-};
-
-Matrix3.rotateMatrix = function(angle, axis, pivot, matrix) {
-  var sin = Math.sin(angle);
-  var cos = Math.cos(angle);
-  var axisX, axisY, axisZ;
-  var m = matrix || new Matrix3();
-
-  if (axis === AXIS.X || axis === AXIS.Y || axis === AXIS.Z) {
-    axisX = axis.x;
-    axisY = axis.y;
-    axisZ = axis.z;
-  } else {
-    // normalize
-    var mag = axis.length();
-
-    if (mag == 0.0) {
-      return m;
-    } else {
-      axisX = axis.x / mag;
-      axisY = axis.y / mag;
-      axisZ = axis.z / mag;
-    }
-  }
-
-  var px = pivot.x;
-  var py = pivot.y;
-  var pz = pivot.z;
-
-  m.mxx = cos + axisX * axisX * (1 - cos);
-  m.mxy = axisX * axisY * (1 - cos) - axisZ * sin;
-  m.mxz = axisX * axisZ * (1 - cos) + axisY * sin;
-
-  m.tx = px * (1 - m.mxx) - py * m.mxy - pz * m.mxz;
-
-  m.myx = axisY * axisX * (1 - cos) + axisZ * sin;
-  m.myy = cos + axisY * axisY * (1 - cos);
-  m.myz = axisY * axisZ * (1 - cos) - axisX * sin;
-  m.ty = py * (1 - m.myy) - px * m.myx - pz * m.myz;
-
-  m.mzx = axisZ * axisX * (1 - cos) - axisY * sin;
-  m.mzy = axisZ * axisY * (1 - cos) + axisX * sin;
-  m.mzz = cos + axisZ * axisZ * (1 - cos);
-  m.tz = pz * (1 - m.mzz) - px * m.mzx - py * m.mzy;
-  return m;
-};
-
-function BasisForPlane(normal, alignY = AXIS.Y, alignZ = AXIS.Z) {
-  let alignPlane, x, y;
-  if (Math.abs(normal.dot(alignY)) < 0.5) {
-    alignPlane = normal.cross(alignY);
-  } else {
-    alignPlane = normal.cross(alignZ);
-  }
-  y = alignPlane.cross(normal);
-  x = y.cross(normal);
-  return [x, y, normal];
-}
-
-export {Matrix3, ORIGIN, IDENTITY_BASIS, AXIS, BasisForPlane}; 
\ No newline at end of file
diff --git a/web/app/sketcher/components/SketchObjectExplorer.jsx b/web/app/sketcher/components/SketchObjectExplorer.jsx
index ba3c335f..4c59deb0 100644
--- a/web/app/sketcher/components/SketchObjectExplorer.jsx
+++ b/web/app/sketcher/components/SketchObjectExplorer.jsx
@@ -9,12 +9,13 @@ import {SketcherAppContext} from "./SketcherAppContext";
 export function SketchObjectExplorer() {
 
   const [modification, setModification] = useState(0);
-  const stream = useStream(ctx => combine(ctx.viewer.streams.objects, ctx.viewer.streams.selection));
+  const objects = useStream(ctx => ctx.viewer.streams.objects);
+  const selection = useStream(ctx.viewer.streams.selection);
   const ctx = useContext(SketcherAppContext);
-  if (!stream) {
+
+  if (!objects || !selection) {
     return null
   }
-  const [objects, selection] = stream;
 
   const select = (obj, exclusive) => {
     let viewer = ctx.viewer;
diff --git a/web/app/sketcher/constr/ANConstraints.js b/web/app/sketcher/constr/ANConstraints.ts
similarity index 93%
rename from web/app/sketcher/constr/ANConstraints.js
rename to web/app/sketcher/constr/ANConstraints.ts
index 8b8c5f82..25325956 100644
--- a/web/app/sketcher/constr/ANConstraints.js
+++ b/web/app/sketcher/constr/ANConstraints.ts
@@ -33,8 +33,15 @@ import {
   LengthAnnotation,
   RadiusLengthAnnotation
 } from "../shapes/annotations/angleAnnotation";
+import {ISolveStage, SolvableObject} from "./solvableObject";
+import {SketchObject} from "../shapes/sketch-object";
+import {IconType} from "react-icons";
 
-export const ConstraintDefinitions = {
+export const ConstraintDefinitions
+  // : {
+  //   [key: string]: ConstraintSchema
+  // }
+= {
 
   PCoincident : {
     id: 'PCoincident',
@@ -338,8 +345,8 @@ export const ConstraintDefinitions = {
         .monomial(-1);
 
 
-      polynomials.push(ellipsePoly());
-      polynomials.push(ellipsePoly());
+      // polynomials.push(ellipsePoly());
+      // polynomials.push(ellipsePoly());
     },
 
   },
@@ -814,12 +821,12 @@ export const ConstraintDefinitions = {
       pt.visitParams(callback);
     },
 
-    collectPolynomials: (polynomials, [px, py], {x, y}) => {
+    collectPolynomials: (polynomials, [px, py], {x, y}: ResolvedConstants) => {
       polynomials.push(new Polynomial(-x).monomial().term(px, POW_1_FN));
       polynomials.push(new Polynomial(-y).monomial().term(py, POW_1_FN));
     },
 
-    setConstantsFromGeometry: ([pt], constants) => {
+    setConstantsFromGeometry: ([pt], constants: ConstantsDefinitions) => {
       constants.x = pt.x + '';
       constants.y = pt.y + '';
     }
@@ -940,11 +947,51 @@ const bezier3Polynomial = (p, t, p0, p1, p2, p3) => new Polynomial()
   .monomial(-1)
     .term(p, POW_1_FN);
 
+
+export type ResolvedConstants = { [p: string]: any };
+export type ConstantsDefinitions = { [p: string]: string };
+
+export interface ConstraintSchema {
+
+  id: string;
+  name: string,
+  icon: IconType,
+  constants?: {
+    [name: string]: {
+      readOnly?: boolean;
+      type: string,
+      description?: string,
+      transform?: (string) => any,
+      initialValue(objects: SolvableObject[]): any;
+    }
+  };
+
+  createAnnotations?: (objects: SolvableObject[], constraintInstance: AlgNumConstraint) =>  SketchObject[];
+
+  defineParamsScope: (object: SolvableObject[], cb: (param: Param) => void) => void;
+
+  collectPolynomials(polynomials: Polynomial[], params: Param[], resolvedConstants: ResolvedConstants, objects: SolvableObject[]): void;
+
+  setConstantsFromGeometry?: (object: SolvableObject[], resolvedConstants: ConstantsDefinitions) => void;
+
+  initialGuess?(params: Param[], resolvedConstants: ResolvedConstants): void;
+}
+
 export class AlgNumConstraint {
 
   static Counter = 0;
 
-  constructor(schema, objects, constants, internal = false) {
+  id: string;
+  objects: SolvableObject[];
+  constants: ConstantsDefinitions;
+  resolvedConstants: ResolvedConstants;
+  internal: boolean;
+  schema: ConstraintSchema;
+  params: Param[];
+  stage: ISolveStage;
+  private annotations: SketchObject[];
+
+  constructor(schema: ConstraintSchema, objects: SolvableObject[], constants?: ConstantsDefinitions, internal?: boolean = false) {
     this.id = schema.id + ':' + (AlgNumConstraint.Counter ++); // only for debug purposes - not persisted
     this.objects = objects;
     this.constants = constants;
@@ -958,18 +1005,6 @@ export class AlgNumConstraint {
       this.schema.defineParamsScope(this.objects, p => this.params.push(p));
     }
 
-    this.modifier = this.schema.modify !== undefined;
-    if (this.modifier) {
-      this.referenceObjects = this.schema.referenceObjects(this.objects);
-      this.managedObjects = this.schema.managedObjects(this.objects);
-      this.managedObjects.forEach(o => {
-        if (o.managedBy) {
-          throw 'there can be only one managing modifier for an object';
-        }
-        o.managedBy = this;
-      });
-    }
-
     if (!this.internal && this.schema.createAnnotations) {
       this.annotations = this.schema.createAnnotations(this.objects, this);
     } else {
@@ -977,8 +1012,8 @@ export class AlgNumConstraint {
     }
   }
 
-  collectPolynomials(polynomials) {
-    this.schema.collectPolynomials(polynomials, this.params, this.resolvedConstants);
+  collectPolynomials(polynomials: Polynomial[]) {
+    this.schema.collectPolynomials(polynomials, this.params, this.resolvedConstants, this.objects);
   }
 
   resolveConstants(expressionResolver) {
@@ -988,7 +1023,7 @@ export class AlgNumConstraint {
       }
       Object.keys(this.constants).map(name => {
         let def = this.schema.constants[name];
-        let val = this.constants[name];
+        let val: any = this.constants[name];
         val = expressionResolver(val);
         if (def.type === 'number') {
           val = parseFloat(val);
@@ -1071,4 +1106,3 @@ export class AlgNumConstraint {
     this.constants[key] = value + ''; // only string are allowed here
   }
 }
-
diff --git a/web/app/sketcher/constr/AlgNumSystem.js b/web/app/sketcher/constr/AlgNumSystem.ts
similarity index 95%
rename from web/app/sketcher/constr/AlgNumSystem.js
rename to web/app/sketcher/constr/AlgNumSystem.ts
index d3361cd1..bb31e3a6 100644
--- a/web/app/sketcher/constr/AlgNumSystem.js
+++ b/web/app/sketcher/constr/AlgNumSystem.ts
@@ -2,8 +2,10 @@ import {prepare} from "./solver";
 import {eqEps} from "../../brep/geom/tolerance";
 import {Polynomial, POW_1_FN} from "./polynomial";
 import {compositeFn} from "gems/func";
+import {AlgNumConstraint} from "./ANConstraints";
+import {SolverParam} from "./solverParam";
 
-const DEBUG = false;
+const DEBUG = true;
 
 export class AlgNumSubSystem {
 
@@ -34,6 +36,18 @@ export class AlgNumSubSystem {
 
   stage = null;
 
+  dof: number = 0;
+
+  requiresHardSolve: boolean = false;
+
+  polynomialIsolations: Isolation[];
+
+  calcVisualLimit: () => number;
+
+  expressionResolver: (string) => any;
+
+  solveStatus: SolveStatus;
+
   constructor(calcVisualLimit, expressionResolver, stage) {
 
     this.calcVisualLimit = calcVisualLimit;
@@ -182,7 +196,7 @@ export class AlgNumSubSystem {
     });
 
     if (DEBUG) {
-      console.log('reducing system:');
+      console.log('reducing system(of', this.polynomials.length, '):');
       this.polynomials.forEach(p => console.log(p.toString()));
     }
 
@@ -502,6 +516,13 @@ export class AlgNumSubSystem {
 
 
 class Isolation {
+  polynomials: Polynomial[];
+  system: AlgNumSubSystem;
+  beingSolvedParams: Set<SolverParam>;
+  beingSolvedConstraints: Set<AlgNumConstraint>;
+  dof: number;
+  solveStatus: SolveStatus;
+  numericalSolver: { system; diagnose; solveSystem; error; updateLock };
 
   constructor(polynomials, system) {
     this.system = system;
@@ -605,3 +626,7 @@ class PolynomialResidual {
 
 }
 
+interface SolveStatus {
+  success: boolean;
+  error: number
+}
\ No newline at end of file
diff --git a/web/app/sketcher/constr/solvableObject.ts b/web/app/sketcher/constr/solvableObject.ts
new file mode 100644
index 00000000..30eefe44
--- /dev/null
+++ b/web/app/sketcher/constr/solvableObject.ts
@@ -0,0 +1,12 @@
+import {Param} from "../shapes/param";
+
+export interface SolvableObject {
+
+  id: string;
+
+}
+
+export interface ISolveStage {
+  objects: Set<SolvableObject>;
+  index: number;
+}
\ No newline at end of file
diff --git a/web/app/sketcher/constr/solver.js b/web/app/sketcher/constr/solver.js
index 0b2ece45..37ebefa3 100644
--- a/web/app/sketcher/constr/solver.js
+++ b/web/app/sketcher/constr/solver.js
@@ -6,28 +6,6 @@ import {ConstantWrapper, EqualsTo} from './solverConstraints'
 import {dog_leg} from '../../math/optim'
 import {newVector} from 'math/vec';
 
-/** @constructor */
-function Param(value, objectParam) {
-  this.reset(value);
-  this.objectParam = objectParam;
-}
-
-Param.prototype.reset = function(value) {
-  this.set(value);
-  this.constant = false;
-  this.j = -1;
-};
-
-Param.prototype.set = function(value) {
-  if (this.constant) return;
-  this.value = value;
-};
-
-Param.prototype.get = function() {
-  return this.value;
-};
-
-Param.prototype.nop = function() {};
 
 /** @constructor */
 function System(constraints) {
@@ -313,4 +291,4 @@ var solve_lm = function(sys, model, jacobian, rough) {
   };
 };
 
-export {Param, prepare}
\ No newline at end of file
+export {prepare}
\ No newline at end of file
diff --git a/web/app/sketcher/constr/solverParam.ts b/web/app/sketcher/constr/solverParam.ts
new file mode 100644
index 00000000..93f59d67
--- /dev/null
+++ b/web/app/sketcher/constr/solverParam.ts
@@ -0,0 +1,35 @@
+import {Param} from "../shapes/param";
+
+export class SolverParam {
+
+  value: number;
+  objectParam: Param;
+  constant: boolean;
+
+  /**
+   * Jacobian position
+   */
+  j: number;
+
+  constructor(value, objectParam) {
+    this.reset(value);
+    this.objectParam = objectParam;
+  }
+
+  reset(value) {
+    this.set(value);
+    this.constant = false;
+    this.j = -1;
+  };
+
+  set(value) {
+    if (this.constant) return;
+    this.value = value;
+  };
+
+  get() {
+    return this.value;
+  }
+
+}
+
diff --git a/web/app/sketcher/parametric.js b/web/app/sketcher/parametric.ts
similarity index 96%
rename from web/app/sketcher/parametric.js
rename to web/app/sketcher/parametric.ts
index f07b4f74..be7fa03b 100644
--- a/web/app/sketcher/parametric.js
+++ b/web/app/sketcher/parametric.ts
@@ -3,6 +3,8 @@ import {AlgNumConstraint, ConstraintDefinitions} from "./constr/ANConstraints";
 import {AlgNumSubSystem} from "./constr/AlgNumSystem";
 import {state, stream} from 'lstream';
 import {toast} from "react-toastify";
+import {ISolveStage, SolvableObject} from "./constr/solvableObject";
+import {Viewer} from "./viewer2d";
 
 export {Constraints, ParametricManager}
 
@@ -31,6 +33,8 @@ class ParametricManager {
   $constantDefinition = state('');
 
   groundStage = new SolveStage(this);
+  viewer: Viewer;
+  messageSink: (msg) => void;
 
   constructor(viewer) {
     this.viewer = viewer;
@@ -240,7 +244,7 @@ class ParametricManager {
     });
   };
 
-  _removeObject = (obj, force) => {
+  _removeObject = (obj, force?) => {
     if (obj.__disposed) {
       return;
     }
@@ -398,10 +402,12 @@ class ParametricManager {
   }
 }
 
-class SolveStage {
+class SolveStage implements ISolveStage{
 
   generators = new Set();
-  objects = new Set();
+  objects = new Set<SolvableObject>();
+  private parametricManager: ParametricManager;
+  private algNumSystem: AlgNumSubSystem;
 
   constructor(parametricManager) {
     this.parametricManager = parametricManager;
@@ -460,6 +466,7 @@ class SolveStage {
   solve(rough) {
     this.algNumSystem.solve(rough);
     this.generators.forEach(gen => {
+      // @ts-ignore
       gen.regenerate(this.viewer);
     })
   }
diff --git a/web/app/sketcher/shapes/param.ts b/web/app/sketcher/shapes/param.ts
index 2cc164dd..4697dea1 100644
--- a/web/app/sketcher/shapes/param.ts
+++ b/web/app/sketcher/shapes/param.ts
@@ -1,15 +1,18 @@
 import {Generator} from "../id-generator";
-import {Param as SolverParam} from '../constr/solver';
+import {SolverParam} from "../constr/solverParam";
 
 export class Param {
 
   id: number;
   value: number;
-  solverParam: any;
+  solverParam: SolverParam;
   private readonly debugSymbol: string;
   normalizer: (number) => any;
   enforceVisualLimit: boolean = false;
 
+  //penalty function constraints
+  constraints?: any[];
+
   constructor(value, debugSymbol) {
     this.id = Generator.genID();
     this.value = value;
diff --git a/web/app/sketcher/shapes/sketch-object.ts b/web/app/sketcher/shapes/sketch-object.ts
index e9834e92..0d774ce1 100644
--- a/web/app/sketcher/shapes/sketch-object.ts
+++ b/web/app/sketcher/shapes/sketch-object.ts
@@ -4,8 +4,9 @@ import {Styles} from "../styles";
 import {NoIcon} from "../icons/NoIcon";
 import {Layer, Viewer} from "../viewer2d";
 import {NOOP} from "gems/func";
+import {SolvableObject} from "../constr/solveObject";
 
-export abstract class SketchObject extends Shape {
+export abstract class SketchObject extends Shape implements SolvableObject {
 
   ref: string;
   id: string;
diff --git a/web/app/sketcher/viewer2d.ts b/web/app/sketcher/viewer2d.ts
index c05e71da..621a7c5f 100644
--- a/web/app/sketcher/viewer2d.ts
+++ b/web/app/sketcher/viewer2d.ts
@@ -9,7 +9,7 @@ import {BasisOrigin} from './shapes/basis-origin';
 import Vector from 'math/vector';
 
 import * as draw_utils from './shapes/draw-utils';
-import {Matrix3} from '../math/l3space';
+import {Matrix3} from 'math/l3space';
 import sketcherStreams, {SketcherStreams} from './sketcherStreams';
 import {BBox, IO} from "./io";
 import {NOOP} from "../../../modules/gems/func";
@@ -358,13 +358,14 @@ export class Viewer {
   };
 
   fit() {
-
+    let count = 0;
     const bbox = new BBox();
     this.accept(obj => {
+      count ++;
       bbox.check(obj);
       return true;
     });
-    if (!bbox.isValid()) {
+    if (count < 2 || !bbox.isValid()) {
       return;
     }
 
diff --git a/web/app/utils/errors.js b/web/app/utils/errors.js
index c6d3fcd1..eca451c1 100644
--- a/web/app/utils/errors.js
+++ b/web/app/utils/errors.js
@@ -22,5 +22,5 @@ CadError.KIND = {
   INVALID_PARAMS: 'INVALID_PARAMS'
 };
 
-CadError.ALGORITMTHM_ERROR_KINDS = ['INTERNAL_ERROR', 'UNSUPPORTED_CASE', 'INVALID_INPUT'];
+CadError.ALGORITHM_ERROR_KINDS = ['INTERNAL_ERROR', 'UNSUPPORTED_CASE', 'INVALID_INPUT'];