Fix http://www.html5gamedevs.com/topic/35913-gui-textblock-flick-on-addcontrol/

dist/preview release/babylon.max.js

@@ -11050,7 +11050,7 @@ var BABYLON;
         });
         Object.defineProperty(Engine, "Version", {
             get: function () {
-                return "3.2.0-alpha10";
+                return "3.2.0-alphaA";
             },
             enumerable: true,
             configurable: true
@@ -21990,7 +21990,7 @@ var BABYLON;
                 if (!BABYLON.CollisionCoordinatorLegacy) {
                     return;
                 }
-                enabled = (enabled && !!Worker);
+                enabled = (enabled && !!Worker && !!BABYLON.CollisionWorker);
                 this._workerCollisions = enabled;
                 if (this.collisionCoordinator) {
                     this.collisionCoordinator.destroy();
@@ -50550,7 +50550,7 @@ var BABYLON;
                 geometryId = geometry ? geometry.id : null;
             }
             else if (mesh instanceof BABYLON.InstancedMesh) {
-                var geometry = mesh.sourceMesh.geometry;
+                var geometry = mesh.sourceMesh && mesh.sourceMesh.geometry;
                 geometryId = geometry ? geometry.id : null;
             }
             var boundingInfo = mesh.getBoundingInfo();

dist/preview release/customConfigurations/minimalGLTFViewer/babylon.max.js

@@ -11050,7 +11050,7 @@ var BABYLON;
         });
         Object.defineProperty(Engine, "Version", {
             get: function () {
-                return "3.2.0-alpha10";
+                return "3.2.0-alphaA";
             },
             enumerable: true,
             configurable: true
@@ -21990,7 +21990,7 @@ var BABYLON;
                 if (!BABYLON.CollisionCoordinatorLegacy) {
                     return;
                 }
-                enabled = (enabled && !!Worker);
+                enabled = (enabled && !!Worker && !!BABYLON.CollisionWorker);
                 this._workerCollisions = enabled;
                 if (this.collisionCoordinator) {
                     this.collisionCoordinator.destroy();
@@ -50550,7 +50550,7 @@ var BABYLON;
                 geometryId = geometry ? geometry.id : null;
             }
             else if (mesh instanceof BABYLON.InstancedMesh) {
-                var geometry = mesh.sourceMesh.geometry;
+                var geometry = mesh.sourceMesh && mesh.sourceMesh.geometry;
                 geometryId = geometry ? geometry.id : null;
             }
             var boundingInfo = mesh.getBoundingInfo();

dist/preview release/customConfigurations/minimalGLTFViewer/es6.js

@@ -11023,7 +11023,7 @@ var BABYLON;
         });
         Object.defineProperty(Engine, "Version", {
             get: function () {
-                return "3.2.0-alpha10";
+                return "3.2.0-alphaA";
             },
             enumerable: true,
             configurable: true
@@ -21963,7 +21963,7 @@ var BABYLON;
                 if (!BABYLON.CollisionCoordinatorLegacy) {
                     return;
                 }
-                enabled = (enabled && !!Worker);
+                enabled = (enabled && !!Worker && !!BABYLON.CollisionWorker);
                 this._workerCollisions = enabled;
                 if (this.collisionCoordinator) {
                     this.collisionCoordinator.destroy();
@@ -50523,7 +50523,7 @@ var BABYLON;
                 geometryId = geometry ? geometry.id : null;
             }
             else if (mesh instanceof BABYLON.InstancedMesh) {
-                var geometry = mesh.sourceMesh.geometry;
+                var geometry = mesh.sourceMesh && mesh.sourceMesh.geometry;
                 geometryId = geometry ? geometry.id : null;
             }
             var boundingInfo = mesh.getBoundingInfo();

dist/preview release/es6.js

@@ -11023,7 +11023,7 @@ var BABYLON;
         });
         Object.defineProperty(Engine, "Version", {
             get: function () {
-                return "3.2.0-alpha10";
+                return "3.2.0-alphaA";
             },
             enumerable: true,
             configurable: true
@@ -21963,7 +21963,7 @@ var BABYLON;
                 if (!BABYLON.CollisionCoordinatorLegacy) {
                     return;
                 }
-                enabled = (enabled && !!Worker);
+                enabled = (enabled && !!Worker && !!BABYLON.CollisionWorker);
                 this._workerCollisions = enabled;
                 if (this.collisionCoordinator) {
                     this.collisionCoordinator.destroy();
@@ -50523,7 +50523,7 @@ var BABYLON;
                 geometryId = geometry ? geometry.id : null;
             }
             else if (mesh instanceof BABYLON.InstancedMesh) {
-                var geometry = mesh.sourceMesh.geometry;
+                var geometry = mesh.sourceMesh && mesh.sourceMesh.geometry;
                 geometryId = geometry ? geometry.id : null;
             }
             var boundingInfo = mesh.getBoundingInfo();

gui/src/controls/container.ts

@@ -80,6 +80,8 @@ module BABYLON.GUI {
                 control.parent = null;
             }
 
+            control.linkWithMesh(null);
+
             this._markAsDirty();
             return this;
         }

gui/src/controls/control.ts

@@ -36,6 +36,7 @@ module BABYLON.GUI {
         private _transformMatrix = Matrix2D.Identity();
         protected _invertTransformMatrix = Matrix2D.Identity();
         protected _transformedPosition = Vector2.Zero();
+        private _onlyMeasureMode = false;
         private _isMatrixDirty = true;
         private _cachedOffsetX: number;
         private _cachedOffsetY: number;
@@ -567,6 +568,7 @@ module BABYLON.GUI {
             this.horizontalAlignment = BABYLON.GUI.Control.HORIZONTAL_ALIGNMENT_LEFT;
             this.verticalAlignment = BABYLON.GUI.Control.VERTICAL_ALIGNMENT_TOP;
             this._linkedMesh = mesh;
+            this._onlyMeasureMode = true;
             this._host._linkedControls.push(this);
         }
 
@@ -701,6 +703,11 @@ module BABYLON.GUI {
             // Transform
             this._transform(context);
 
+            if (this._onlyMeasureMode) {
+                this._onlyMeasureMode = false;
+                return false; // We do not want rendering for this frame as they are measure dependant information that need to be gathered
+            }
+
             // Clip
             this._clip(context);
             context.clip();