anchor.diff:  
   == Shape Keys
   
  -Shape keys in Blender are used to apply a deformation to a mesh without changing the underlying vertices. The glTF exporter ignores shape keys unless they are part of an animation.
  +Shape keys in Blender are used to apply a deformation to a mesh without changing the underlying vertices. The glTF exporter ignores shape keys unless they are part of an animation. To include shape keys in the export, select the `Shape Keys` option in the `Animation` tab of the glTF export options.
   
   == Export options
   
  
positive.code: 
  Ultimately all jME projects should use the `.j3o` format for storing assets. However during development a format is required to export scenes from Blender in a format suitable for conversion (either through the SDK or directly through code).
  
  Use of glTF (or another standard format) has a significant advantage of direct import of `.blend` files: new versions of Blender with significant enhancements are released fairly regularly. Using a standard format allows new features to be used without requiring updates to the Blender importer.
  
  [NOTE]
  Blender 2.7 had a number of problems in exporting glTF; these notes refer exclusively to Blender 2.8+
  
negative.code: . If an object has a single material, the corresponding node in the imported structure will have type `Geometry` with the object's mesh and the associated material.
  . If an object has more than one material, the corresponding node will have type `Node` with 1 child per material. Each of these children will be a `Geometry` with the associated material and a mesh containing the vertices assigned to the material.
  
  For example, if a blender scene has the following structure
  
  ....
  Scene collection
      Collection A
          Tree (Object)
              Tree_Mesh (Mesh)
          Car (Object)
              Car_Mesh (Mesh)
                  Body (Material)
          House (Object)
              House_Mesh (Mesh)
                  Walls (Material)
                  Roof (Material)
      Collection B
          Person_Armature (Armature)
              Root (Bone)
                  Head (Bone)
              Animations
                  Walk (Action)
                  NLA Tracks
                      NLA Track
                          Run (Action)
              Person (Object)
                  Animation
                      Walk (Action link)
                  Person_Mesh
  ....
  
  Then after export to glTF format and import to jME it will look like:
  
  ....
  Scene (Node)
      Tree (Geometry)
          Default (Material)
      Car (Geometry)
          Body (Material)
      House (Node)
          House_1 (Geometry)
              Walls (Material)
          House_1 (Geometry)
              Roof (Material)
      Person_Armature (Node)
          Animations (Animation Control)
              Walk (Animation)
              Run (Animation)
          Person (Geometry)
              Animations (Animation Control)
                  Walk (Animation)
  ....
  
  For example, the animated person could be loaded with a custom material assigned as follows:
  
  [source,java]
  ----
  ModelKey key = new ModelKey("Models/model.glb");
  Node scene = (Node)assetManager.loadModel(key);
  Node person = scene.getChild("Person_Armature");
  Geometry geometry = (Geometry)person.getChild("Person");
  geometry.setMaterial(customMaterial);
  root.attachChild(person);
  ----
  
  == Additional Reading
  
  Thread announcing glTF support: https://hub.jmonkeyengine.org/t/jme-gltf-support/39174
  
  Documentation for the python export functions https://docs.blender.org/api/current/bpy.ops.export_scene.html
  
  glTF specification https://github.com/KhronosGroup/glTF/tree/master/specification/2.0
  