I have been playing around with the new model support and hit a problem with what appear to be materials.
I have grabbed a Blender model from the Nasa website and exported it from Blender with and without materials. When exporting without materials the model renders ok in the Sandcastle running locally. When exporting the model with materials the following error is thrown
An error occurred while rendering. Rendering has stopped. TypeError: images[textures[name].source] is undefined
In both cases the model was converted to glTF using the online conversion tool (http://cesiumjs.org/convertmodel.html)
works.zip (264 KB)
fails.zip (575 KB)
635572main_jpl-vtad-Deep_Space_1.zip (1.91 MB)