3d bbox doc t2 (#424)

* Updated documentation for 3dbbox about skinnedmeshrenderers

* Updated text

com.unity.perception/CHANGELOG.md

 
 Fixed an indexing issue with the IdLabelConfig editor. When a new label was added to an empty Id Label Config with Auto Assign IDs enabled, the starting id (0 or 1) was ignored and the new label would always have an id of 0.
 
+Updated documentation to reflect that the 3D Bounding Box Labeler does not support Skinned Mesh Renderers.
+
 ## [0.8.0-preview.4] - 2021-07-05
 
 ### Upgrade Notes

com.unity.perception/Documentation~/FAQ/FAQ.md

 ---
 </details>
 
+<details>
+  <summary><strong>Q: Why aren't my character models labeled by the 3D Bounding Box Labeler?</strong></summary><br>
+
+Most human character models use Skinned Mesh Renderers. Unfortunately, at this time, GameObjects using this type of renderer are not supported by the 3D Bounding Box Labeler.
+
+---
+</details>
 
 ## <a name="randomization">Randomization</a>
 

com.unity.perception/Documentation~/PerceptionCamera.md

 
 ### Bounding Box 3D Labeler
 
-The Bounding Box 3D Ground Truth Labeler produces 3D ground truth bounding boxes for each labeled game object in the scene. Unlike the 2D bounding boxes, 3D bounding boxes are calculated from the labeled meshes in the scene and all objects (independent of their occlusion state) are recorded.
+The Bounding Box 3D Ground Truth Labeler produces 3D ground truth bounding boxes for each labeled GameObject in the Scene. Unlike the 2D bounding boxes, 3D bounding boxes are calculated from the labeled meshes in the scene and all objects (independent of their occlusion state) are recorded.  
+***Note:*** The Bounding Box 3D Labeler does not support GameObjects with Skinned Mesh Renderers, they will be ignored  
 
 ### Object Count Labeler
 

com.unity.perception/Runtime/GroundTruth/Labelers/BoundingBox3DLabeler.cs

     /// <summary>
     /// Produces 3d bounding box ground truth for all visible and <see cref="Labeling"/> objects each frame.
     /// </summary>
+    /// <remarks>The BoundingBox3DLabeler does not support <see cref="SkinnedMeshRenderer"/> objects, they will be ignored.</remarks>
     public class BoundingBox3DLabeler : CameraLabeler
     {
         ///<inheritdoc/>