diff --git a/web/app/3d/debug.js b/web/app/3d/debug.js
index 695b1542..dfc1938f 100644
--- a/web/app/3d/debug.js
+++ b/web/app/3d/debug.js
@@ -161,8 +161,8 @@ function addGlobalDebugActions(app) {
       app.findAllSolidsOnScene().forEach(s => s.cadGroup.traverse(o => o.visible = false));
       app.viewer.render();
     },
-    Solids: () => {
-      app.findAllSolidsOnScene().forEach(s => s.cadGroup.traverse(o => o.visible = false));
+    ShowSolids: () => {
+      app.findAllSolidsOnScene().forEach(s => s.cadGroup.traverse(o => o.visible = true));
       app.viewer.render();
     },
     Clear: () => {
diff --git a/web/app/brep/debug/brep-debug.js b/web/app/brep/debug/brep-debug.js
index 6f06e05a..97314429 100644
--- a/web/app/brep/debug/brep-debug.js
+++ b/web/app/brep/debug/brep-debug.js
@@ -50,6 +50,11 @@ class BRepDebug {
   transferEdge(edge, face, chosenEdge) {
     this.currentBooleanSession.transferedEdges.push({edge, face, chosenEdge});
   }
+
+  faceFilter(connectedToAffectedFaces, allFaces) {
+    this.currentBooleanSession.faceFilter.connectedToAffectedFaces = connectedToAffectedFaces;
+    this.currentBooleanSession.faceFilter.allFaces = allFaces;
+  }
 }
 
 class BooleanSession {
@@ -63,6 +68,10 @@ class BooleanSession {
     this.transferedEdges = [];
     this.mergeFacesLoopDetection = [];
     this.currentLoopDetection = null;
+    this.faceFilter = {
+      connectedToAffectedFaces: null,
+      allFaces: null,
+    };
   }
 }
 
diff --git a/web/app/brep/debug/debugger/brepDebugger.jsx b/web/app/brep/debug/debugger/brepDebugger.jsx
index e663bcb7..5ec46a32 100644
--- a/web/app/brep/debug/debugger/brepDebugger.jsx
+++ b/web/app/brep/debug/debugger/brepDebugger.jsx
@@ -5,6 +5,7 @@ import ShellExplorer from './shellExplorer';
 import LoopDetectionExplorer from './loopDetectionExplorer';
 import Section from './section'
 import {EdgeTransferExplorer} from "./edgeTransferExplorer";
+import {FaceFilterExplorer} from "./faceFilterExplorer";
 
 export default class BrepDebugger extends React.PureComponent {
 
@@ -85,11 +86,9 @@ export default class BrepDebugger extends React.PureComponent {
           <Section name='loops validation' accent>
             loops validation...
           </Section>
-          <Section name='loops filter' accent>
-            loops filter...
+          <Section name='face filter' accent>
+            {session.faceFilter && <FaceFilterExplorer {...session.faceFilter} group3d={brepDebugGroup} /> } 
           </Section>
-          
-
         </Section>)}
       </div> 
     </div>;
diff --git a/web/app/brep/debug/debugger/faceFilterExplorer.jsx b/web/app/brep/debug/debugger/faceFilterExplorer.jsx
new file mode 100644
index 00000000..bfe0a669
--- /dev/null
+++ b/web/app/brep/debug/debugger/faceFilterExplorer.jsx
@@ -0,0 +1,28 @@
+import React from 'react';
+import {FaceExplorer} from "./shellExplorer";
+import Section from './section';
+import {
+  getFacesViewObjects, InteractiveSection, TAB,
+} from "./utils";
+
+
+export function FaceFilterExplorer({connectedToAffectedFaces, allFaces, group3d}) {
+  connectedToAffectedFaces = connectedToAffectedFaces || [];
+  allFaces = allFaces || [];
+  let notConnectedToAffectedFaces = allFaces.filter(f => connectedToAffectedFaces.indexOf(f) === -1);
+  let category = 'face-filter';
+  let context = {connectedToAffectedFaces, notConnectedToAffectedFaces};
+  return <InteractiveSection name='analyzed faces' closable defaultClosed={false} 
+                      {...{viewObjectsProvider: getFacesViewObjects, topoObj: allFaces, group3d, category, context}}>
+
+    <Section name='connected to affected' tabs={TAB} accent>
+      {connectedToAffectedFaces.length  === 0 ? '<empty>' : null }
+      {connectedToAffectedFaces.map((face, i) => <FaceExplorer key={i} {...{face, group3d, category, context}} />)}
+    </Section>
+    <Section name='not connected to affected' tabs={TAB} accent>
+      {notConnectedToAffectedFaces.length  === 0 ? '<empty>' : null }
+      {notConnectedToAffectedFaces.map((face, i) => <FaceExplorer key={i} {...{face, group3d, category, context}} />)}
+    </Section>
+  </InteractiveSection>
+
+}
diff --git a/web/app/brep/debug/debugger/shellExplorer.jsx b/web/app/brep/debug/debugger/shellExplorer.jsx
index e552ec0f..ce1ac0a2 100644
--- a/web/app/brep/debug/debugger/shellExplorer.jsx
+++ b/web/app/brep/debug/debugger/shellExplorer.jsx
@@ -1,7 +1,8 @@
 import React, {Fragment as FR} from 'react';
 import Section from "./section";
 import {
-  ActiveLabel, Controls, getEdgesViewObjects, getEdgeViewObjects, getFaceViewObjects, getLoopsViewObjects,
+  ActiveLabel, Controls, getEdgesViewObjects, getEdgeViewObjects, getFacesViewObjects, getFaceViewObjects,
+  getLoopsViewObjects,
   getLoopViewObjects,
   getVertexViewObjects, InteractiveSection, mapIterable,
   TAB
@@ -11,12 +12,15 @@ export default class ShellExplorer extends React.PureComponent {
 
   render() {
     let {shell, group3d} = this.props;
+
+    let category='default';
+    let context = null;
+    let faces = shell ? shell.faces : [];
     
-    return <div className='shell-explorer'>
-      <Section name={`shell ${shell ? shell.refId : 'UNAVAILABLE'}`} closable>
-        {shell && shell.faces.map(face => <FaceExplorer key={face.refId} {...{face, group3d}} category='default' context={null} />)}
-      </Section>
-    </div>;
+    return <InteractiveSection name={`shell ${shell ? shell.refId : 'UNAVAILABLE'}`} closable defaultClosed={false}
+                               {...{viewObjectsProvider: getFacesViewObjects, topoObj: faces, group3d, category, context}}>
+        {faces.map(face => <FaceExplorer key={face.refId} {...{face, group3d, category, context}} />)}
+    </InteractiveSection>;
   }
 }
 
diff --git a/web/app/brep/debug/debugger/utils.jsx b/web/app/brep/debug/debugger/utils.jsx
index 29a49e7c..9dae1731 100644
--- a/web/app/brep/debug/debugger/utils.jsx
+++ b/web/app/brep/debug/debugger/utils.jsx
@@ -3,6 +3,10 @@ import {AQUA, BLACK, BLUE, cycleColor, DETECTED_EDGE, DISCARDED_EDGE, GREEN, RED
 import {distanceAB3} from "../../../math/math";
 import Section from "./section";
 
+export function getFacesViewObjects(group3d, category, context, out, faces) {
+  forEach(faces, getFaceViewObjects.bind(null, group3d, category, context, out));
+}
+
 export function getFaceViewObjects(group3d, category, context, out, face) {
   return getLoopsViewObjects(group3d, category, context, out, face.loops);
 }
@@ -137,6 +141,14 @@ export function getInitColor(category, obj, context) {
         return BLACK;
       }
     }
+    case 'face-filter': {
+      let {connectedToAffectedFaces, notConnectedToAffectedFaces} = context;
+      if (connectedToAffectedFaces.indexOf(obj.loop.face) > -1) {
+        return WHITE;
+      } else {
+        return BLACK;
+      } 
+    }
     default:
       switch (obj.constructor.name) {
         case 'HalfEdge': return SALMON;
diff --git a/web/app/brep/operations/boolean.js b/web/app/brep/operations/boolean.js
index c50c4c6b..323573ec 100644
--- a/web/app/brep/operations/boolean.js
+++ b/web/app/brep/operations/boolean.js
@@ -137,7 +137,6 @@ export function BooleanAlgorithm( shellA, shellB, type ) {
 
   faces = filterFaces(faces, shellA, shellB, type !== TYPE.UNION);
   
-  
   const result = new Shell();
   faces.forEach(face => {
     face.shell = result;
@@ -403,6 +402,7 @@ function mergeFaces(facesA, facesB, opType) {
   let detectedLoops = detectLoops(originFace.surface, graph);
   for (let loop of detectedLoops) {
     for (let edge of loop.halfEdges) {
+      EdgeSolveData.setPriority(edge, 1);
       discardedEdges.delete(edge);
     }
   }
@@ -561,39 +561,40 @@ function filterFaces(faces, a, b, isIntersection) {
   if (FILTER_STRATEGY === FILTER_STRATEGIES.RAY_CAST) {
     return filterByRayCast(faces, a, b, isIntersection);
   } else if (FILTER_STRATEGY === FILTER_STRATEGIES.NEW_EDGES) {
-    return filterFacesByNewEdges(faces, a, b, isIntersection);
+    return filterFacesByNewEdges(faces);
   } else {
     throw 'unsupported';
   }
 }
 
 function filterFacesByNewEdges(faces) {
-
-  function isFaceContainNewEdge(face) {
+  
+  function doesFaceContainNewEdge(face) {
     for (let e of face.edges) {
-      if (getPriority(e) > 0) {
+      if (getPriority(e) > 0 || getPriority(e.twin()) > 0) {
         return true;
       }
     }
     return false;
   }
   
-  const validFaces = new Set(faces);
-  const result = new Set();
+  const resultSet = new Set();
   for (let face of faces) {
     // __DEBUG__.Clear();
     // __DEBUG__.AddFace(face);
-    traverseFaces(face, validFaces, (it) => {
-      if (result.has(it) || isFaceContainNewEdge(it)) {
-        result.add(face);
+    traverseFaces(face, (it) => {
+      if (resultSet.has(it) || doesFaceContainNewEdge(it)) {
+        resultSet.add(face);
         return true;
       }
     });
   }
+  const result = Array.from(resultSet)
+  BREP_DEBUG.faceFilter(result, faces);
   return result;
 }
 
-function traverseFaces(face, validFaces, callback) {
+function traverseFaces(face, callback) {
   const stack = [face];
   const seen = new Set();
   while (stack.length !== 0) {
@@ -603,14 +604,9 @@ function traverseFaces(face, validFaces, callback) {
     if (callback(face) === true) {
       return;
     }
-    if (!validFaces.has(face)) continue;
     for (let loop of face.loops) {
       for (let halfEdge of loop.halfEdges) {
-        for (let twin of halfEdge.twins()) {
-          if (validFaces.has(twin.loop.face)) {
-            stack.push(twin.loop.face)
-          }
-        }
+        stack.push(halfEdge.twin().loop.face);
       }
     }
   }
@@ -822,10 +818,6 @@ function transferEdges(faceSource, faceDest, operationType) {
         continue;    
       }
       if (edgeCollinearToFace(edge, faceDest)) {
-        //not coincide with an edge
-        if (!faceDest.rayCast(edge.edge.curve.middlePoint()).strictInside) {
-          continue;          
-        }
         let validEdge = chooseValidEdge(edge, faceDest, operationType);
         BREP_DEBUG.transferEdge(edge, faceDest, validEdge);
         let twin = validEdge.twin();