Merge remote-tracking branch 'origin/prerelease/2.1.0_stabilization' into prerelease/2.1.0_bugs/removeSourceFor21Release

Author: Andrei Borodin

Assets/MixedReality.Toolkit.Foundation.nuspec

@@ -19,7 +19,7 @@
   <files>
     <file src="MixedRealityToolkit\**" exclude="*.nuspec;*.nuspec.meta;*.props;*.props.meta;*.targets;*.targets.meta;MixedRealityToolkit\toc.yml*" target="MRTK\" />
     <file src="MixedRealityToolkit.Providers\**" exclude="*.nuspec;*.nuspec.meta;*.props;*.props.meta;*.targets;*.targets.meta;MixedRealityToolkit.Providers\License.txt*;MixedRealityToolkit.Providers\Version.txt*" target="MRTK\" />
-    <file src="MixedRealityToolkit.SDK\**" exclude="*.nuspec;*.nuspec.meta;*.props;*.props.meta;*.targets;*.targets.meta;MixedRealityToolkit.SDK\License.txt*;MixedRealityToolkit.SDK\Version.txt*;MixedRealityToolkit.SDK\toc.yml*;MixedRealityToolkit.SDK\StandardAssets.meta" target="MRTK\" />
+    <file src="MixedRealityToolkit.SDK\**" exclude="*.nuspec;*.nuspec.meta;*.props;*.props.meta;*.targets;*.targets.meta;MixedRealityToolkit.SDK\License.txt*;MixedRealityToolkit.SDK\Version.txt*;MixedRealityToolkit.SDK\toc.yml*;MixedRealityToolkit.SDK\StandardAssets.meta;MixedRealityToolkit.SDK\StandardAssets\Fonts.meta;MixedRealityToolkit.SDK\StandardAssets\Materials.meta;MixedRealityToolkit.SDK\StandardAssets\Shaders.meta;MixedRealityToolkit.SDK\StandardAssets\Textures.meta" target="MRTK\" />
     <file src="MixedRealityToolkit.Services\**" exclude="*.nuspec;*.nuspec.meta;*.props;*.props.meta;*.targets;*.targets.meta;MixedRealityToolkit.Services\License.txt*;MixedRealityToolkit.Services\Version.txt*" target="MRTK\" />
 
     <file src="MixedRealityToolkit\MixedReality.Toolkit.targets" target="build\Microsoft.MixedReality.Toolkit.Foundation.targets" />

Assets/MixedRealityToolkit/Providers/Hands/BaseHandVisualizer.cs

@@ -182,13 +182,16 @@ public void OnHandMeshUpdated(InputEventData<HandMeshInfo> eventData)
             {
                 Mesh mesh = handMeshFilter.mesh;
 
+                bool meshChanged = false;
                 // On some platforms, mesh length counts may change as the hand mesh is updated.
                 // In order to update the vertices when the array sizes change, the mesh
                 // must be cleared per instructions here:
                 // https://docs.unity3d.com/ScriptReference/Mesh.html
-                if (lastHandMeshVertices.Length != 0 &&
+                if (lastHandMeshVertices != null &&
+                    lastHandMeshVertices.Length != 0 &&
                     lastHandMeshVertices.Length != eventData.InputData.vertices?.Length)
                 {
+                    meshChanged = true;
                     mesh.Clear();
                 }
 
@@ -202,7 +205,10 @@ public void OnHandMeshUpdated(InputEventData<HandMeshInfo> eventData)
                     mesh.uv = eventData.InputData.uvs;
                 }
 
-                mesh.RecalculateBounds();
+                if (meshChanged)
+                {
+                    mesh.RecalculateBounds();
+                }
 
                 handMeshFilter.transform.position = eventData.InputData.position;
                 handMeshFilter.transform.rotation = eventData.InputData.rotation;

Documentation/README_ExampleHub.md

@@ -6,6 +6,9 @@ MRTK Examples Hub is a Unity scene that makes it easy to experience multiple sce
 
 **MRTKExamplesHub.unity** is the container scene that has shared components including ``MixedRealityToolkit`` and ``MixedRealityPlayspace``. **MRTKExamplesHubMainMenu.unity** scene has the cube buttons.
 
+## Prerequisite ##
+MRTK Examples Hub uses [Scene Transition Service](https://microsoft.github.io/MixedRealityToolkit-Unity/Documentation/Extensions/SceneTransitionService/SceneTransitionServiceOverview.html) and related scripts. If you are using MRTK through Unity packages, please import **Microsoft.MixedReality.Toolkit.Unity.Extensions.x.x.x.unitypackage** which is part of the [release packages](https://github.com/microsoft/MixedRealityToolkit-Unity/releases). If you are using MRTK through the repository clone, you should already have **MixedRealityToolkit.Extensions** folder in your project.
+
 ## MRTKExamplesHub Scene and the Scene System ##
 Open **MRTKExamplesHub.unity** which is located at ``MixedRealityToolkit.Examples/Demos/ExamplesHub/Scenes/`` It is an empty scene with MixedRealityToolkit, MixedRealityPlayspace and LoadHubOnStartup. This scene is configured to use MRTK's Scene System. Click ``MixedRealitySceneSystem`` under MixedRealityToolkit. It will display the Scene System's information in the Inspector panel.
 <br/><br/><img src="../Documentation/Images/ExamplesHub/MRTK_ExamplesHub_Hierarchy.png" width="300">

pipelines/ci-release.yml

@@ -6,7 +6,7 @@ name: $(Date:yyyyMMdd)v$(Rev:r)
 variables:
   UnityVersion: Unity2018.3.7f1
   MRTKVersion: 2.1.0  # Major.Minor.Patch
-  MRTKReleaseTag: 'alpha'  # final version component, e.g. 'RC2.1' or empty string
+  MRTKReleaseTag: ''  # final version component, e.g. 'RC2.1' or empty string
 
 jobs:
 - job: CIReleaseValidation