diff --git a/web/app/canvas.js b/web/app/canvas.js
index 954dc22b..6285d6f5 100644
--- a/web/app/canvas.js
+++ b/web/app/canvas.js
@@ -25,6 +25,12 @@ TCAD.TWO.Styles = {
     lineWidth : 2,
     strokeStyle : "#00FF00",
     fillStyle : "#00FF00"
+  },
+
+  DIM : {
+    lineWidth : 1,
+    strokeStyle : "#bcffc1",
+    fillStyle : "#00FF00"
   }
 
 };
@@ -81,6 +87,9 @@ TCAD.TWO.Viewer = function(canvas) {
   this.snapped = [];
   
   this._setupServiceLayer();
+  this.dimLayer = new TCAD.TWO.Layer("_dim", TCAD.TWO.Styles.DIM);
+  this.layers.push(this.dimLayer);
+
   this.refresh();
 };
 
@@ -115,7 +124,7 @@ TCAD.TWO.Viewer.prototype.remove = function(obj) {
   }
 };
 
-TCAD.TWO.Viewer.prototype.search = function(x, y, buffer, deep, onlyPoints) {
+TCAD.TWO.Viewer.prototype.search = function(x, y, buffer, deep, onlyPoints, filter) {
 
   buffer *= 0.5;
   
@@ -126,25 +135,33 @@ TCAD.TWO.Viewer.prototype.search = function(x, y, buffer, deep, onlyPoints) {
   var unreachable = buffer * 2;
   var heroLength = unreachable; // unreachable
 
+  function isFiltered(o) {
+    for (var i = 0; i < filter.length; ++i) {
+      if (filter[i] === o) return true;
+    }
+    return false;
+  }
+
   for (var i = 0; i < this.layers.length; i++) {
     var objs = this.layers[i].objects;
     for (var j = 0; j < objs.length; j++) {
       var l = unreachable + 1;
-      var hit = !objs[j].acceptV(true, function(o) {
+      var before = pickResult.length;
+      objs[j].acceptV(true, function(o) {
         if (onlyPoints && o._class !== 'TCAD.TWO.EndPoint') {
           return false;  
         }
         l = o.normalDistance(aim);
-        if (l >= 0 && l <= buffer) {
+        if (l >= 0 && l <= buffer && !isFiltered(o)) {
           pickResult.push(o);
           return false;
         }
         return true;
       });
-      
+      var hit = before - pickResult.length != 0;
       if (hit) {
         if (!deep && pickResult.length != 0) return pickResult;
-        if (l < heroLength) {
+        if (l >= 0 && l < heroLength) {
           heroLength = l;
           heroIdx = pickResult.length - 1;
         }
@@ -168,7 +185,6 @@ TCAD.TWO.Viewer.prototype._setupServiceLayer = function() {
   layer = new TCAD.TWO.Layer("_selection", TCAD.TWO.Styles.DEFAULT);
   layer.objects = this.selected;
   this._serviceLayers.push(layer);
-  
 };
 
 TCAD.TWO.Viewer.prototype.refresh = function() {
@@ -209,14 +225,9 @@ TCAD.TWO.Viewer.prototype.repaint = function() {
 
 TCAD.TWO.Viewer.prototype.snap = function(x, y, excl) {
   this.cleanSnap();
-  var snapTo = this.search(x, y, 20 / this.scale, false, true);
+  var snapTo = this.search(x, y, 20 / this.scale, true, true, excl);
   if (snapTo.length > 0) {
     snapTo = snapTo[0];
-    for (var i = 0; i < excl.length; i++) {
-      if (excl[i] === snapTo) {
-        return;
-      }
-    }
     this.mark(snapTo, TCAD.TWO.Styles.SNAP);
     this.snapped.push(snapTo);
     return snapTo;
@@ -271,7 +282,7 @@ TCAD.TWO.Viewer.prototype.select = function(objs, exclusive) {
 
 TCAD.TWO.Viewer.prototype.pick = function(e) {
   var m = this.screenToModel(e);
-  return this.search(m.x, m.y, 20 / this.scale, true, false);
+  return this.search(m.x, m.y, 20 / this.scale, true, false, []);
 };
 
 TCAD.TWO.Viewer.prototype.mark = function(obj, style) {
diff --git a/web/app/main2d.js b/web/app/main2d.js
index 6b57c5fe..a68a90d6 100644
--- a/web/app/main2d.js
+++ b/web/app/main2d.js
@@ -59,6 +59,10 @@ TCAD.App2D = function() {
     app.viewer.toolManager.releaseControl();
   });
 
+  this.registerAction('addDim', "Add Dimension", function () {
+    app.viewer.toolManager.takeControl(new TCAD.TWO.AddDimTool(app.viewer, app.viewer.dimLayer));
+  });
+
   this.registerAction('save', "Save", function () {
       var sketch = {};
       //sketch.boundary = boundary;
diff --git a/web/app/sketch/dim.js b/web/app/sketch/dim.js
new file mode 100644
index 00000000..61152669
--- /dev/null
+++ b/web/app/sketch/dim.js
@@ -0,0 +1,150 @@
+
+TCAD.TWO.Dimension = function(a, b) {
+  TCAD.TWO.SketchObject.call(this);
+  this.a = a;
+  this.b = b;
+  this.flip = false;
+};
+
+TCAD.TWO.utils.extend(TCAD.TWO.Dimension, TCAD.TWO.SketchObject);
+
+TCAD.TWO.Dimension.prototype._class = 'TCAD.TWO.Dimension';
+
+TCAD.TWO.Dimension.prototype.collectParams = function(params) {
+};
+
+TCAD.TWO.Dimension.prototype.getReferencePoint = function() {
+  return this.a;
+};
+
+TCAD.TWO.Dimension.prototype.translateImpl = function(dx, dy) {
+};
+
+TCAD.TWO.Dimension.prototype.drawImpl = function(ctx, scale) {
+
+  var off = 30;
+
+  var a = this.flip ? this.b : this.a;
+  var b = this.flip ? this.a : this.b;
+
+  var d = TCAD.math.distanceAB(a, b);
+
+  var _vx = - (b.y - a.y);
+  var _vy = b.x - a.x;
+
+  //normalize
+  var _vxn = _vx / d;
+  var _vyn = _vy / d;
+
+  _vx = _vxn * off;
+  _vy = _vyn * off;
+
+  ctx.beginPath();
+
+  var _ax = a.x + _vx;
+  var _ay = a.y + _vy;
+  var _bx = b.x + _vx;
+  var _by = b.y + _vy;
+
+  ctx.moveTo(_ax, _ay);
+  ctx.lineTo(_bx, _by);
+
+
+  function drawRef(a) {
+    ctx.moveTo(a.x, a.y);
+    var off2 = 1.2;
+    ctx.lineTo(a.x + _vx * off2, a.y + _vy * off2);
+  }
+
+  drawRef(a);
+  drawRef(b);
+
+  ctx.closePath();
+  ctx.stroke();
+
+  function drawArrow(x, y) {
+    var s1 = 50;
+    var s2 = 20;
+    ctx.lineCap = 'round';
+    ctx.beginPath();
+    ctx.moveTo(x, y);
+    ctx.lineTo(x - s1, y - s2);
+    ctx.stroke();
+  }
+
+//  drawArrow(_ax, _ay);
+//  drawArrow(_bx, _by);
+
+  ctx.font="12px Arial";
+  var txt = d.toFixed(2);
+  var h = d / 2 - ctx.measureText(txt).width / 2;
+
+  if (h > 0) {
+    var tx = _ax - (- _vyn) * h;
+    var ty = _ay - (  _vxn) * h;
+    ctx.save();
+    ctx.translate(tx, ty);
+    ctx.fillText(txt ,0, 0);
+    ctx.restore();
+  }
+
+};
+
+TCAD.TWO.Dimension.prototype.normalDistance = function(aim) {
+  return -1;
+};
+
+TCAD.TWO.AddDimTool = function(viewer, layer) {
+  this.viewer = viewer;
+  this.layer = layer;
+  this.dim = null;
+  this._v = new TCAD.Vector(0, 0, 0);
+};
+
+TCAD.TWO.AddDimTool.prototype.keydown = function(e) {};
+TCAD.TWO.AddDimTool.prototype.keypress = function(e) {};
+TCAD.TWO.AddDimTool.prototype.keyup = function(e) {};
+TCAD.TWO.AddDimTool.prototype.cleanup = function(e) {};
+
+TCAD.TWO.AddDimTool.prototype.mousemove = function(e) {
+  var p = this.viewer.screenToModel(e);
+  this.viewer.snap(p.x, p.y, []);
+  if (this.dim != null) {
+    this.dim.b.x = p.x;
+    this.dim.b.y = p.y;
+  }
+  this.viewer.refresh();
+};
+
+TCAD.TWO.AddDimTool.prototype.mouseup = function(e) {
+
+  if (e.button > 0 && this.dim != null) {
+    this.dim.flip = !this.dim.flip;
+    this.viewer.refresh();
+    return;
+  }
+
+  if (this.viewer.snapped.length == 0) {
+    return;
+  }
+
+  var p = this.viewer.snapped.pop();
+  this.viewer.cleanSnap();
+
+  if (this.dim == null) {
+    this.dim = new TCAD.TWO.Dimension(p, new TCAD.TWO.EndPoint(p.x, p.y));
+    this.layer.objects.push(this.dim);
+    this.viewer.refresh();
+  } else {
+    this.dim.b = p;
+    this.viewer.toolManager.releaseControl();
+    this.viewer.refresh();
+  }
+};
+
+TCAD.TWO.AddDimTool.prototype.mousedown = function(e) {
+};
+
+TCAD.TWO.AddDimTool.prototype.mousewheel = function(e) {
+};
+
diff --git a/web/sketcher.html b/web/sketcher.html
index 784371bd..20257c1c 100644
--- a/web/sketcher.html
+++ b/web/sketcher.html
@@ -188,6 +188,8 @@
   <script src="app/sketch/arc.js"></script>
   <script src="app/sketch/circle.js"></script>
   <script src="app/sketch/segment.js"></script>
+  <script src="app/sketch/dim.js"></script>
+
   <script src="app/math/math.js"></script>
   <script src="app/math/matrix.js"></script>
   <script src="app/math/optim.js"></script>
@@ -257,7 +259,7 @@
     --><button class="btn tbtn act-addArc sep" style="background-image: url(img/arc.png);" type="submit" value=""></button><!--
     --><button class="btn tbtn" style="background-image: url(img/hdim.png);" type="submit" value=""></button><!--
     --><button class="btn tbtn" style="background-image: url(img/vdim.png);" type="submit" value=""></button><!--
-    --><button class="btn tbtn" style="background-image: url(img/dim.png);" type="submit" value=""></button><!--
+    --><button class="btn tbtn act-addDim" style="background-image: url(img/dim.png);" type="submit" value=""></button><!--
     --><button class="btn tbtn" style="background-image: url(img/ddim.png);" type="submit" value=""></button><!--
     -->
   </div>