Rendering instances of model nodes (Item3Ds)

• Given a model's scene-graph in a QML Mesh object
• When I reference a node in that graph from another Mesh as part of a 3D Item,
• Then the node is rendered using the correct assigned, default and/or inherited properties
• And the entire scene is rendered as a single scene graph to improve rendering performance.

Developer Notes:

Rendering the scene once allows for a pre-render pass of the scene to optimize it for OpenGL performance.

This will involve replacing the entire Item3D drawing procedure with a dynamically created scenegraph for the viewport.