Separate subunits are not coloured differently

[ning-y]

The current TCL script (through VMD) creates Wavefront OBJ renders of the PDB files where each protein subunit is coloured differently from the other (that is, they can be distinguished by colour).

The library I am using to convert these Wavefrontn OBJ files to Sceneform-compatible glTF/glb files do not retain this colouring after conversion, so the whole protein, when rendered in AR, is uniform in colour.

[ning-y]

See: javagl/JglTF#27