Work around issues with black material surfaces

[randallfrank]

When possible, use the JSON description of the material to improve on the simpler protobuffer color scheme.

[david-bremer]

I applied 8 metallic materials to 8 rocky shapes, and they came through where one would expect, for all of the shapes defined by a mesh. They look a little different, but the base color differs, and the shininess comes through.

The color is not applied to the spheres, which use some other shader, so that is expected.

[randallfrank]

I applied 8 metallic materials to 8 rocky shapes, and they came through where one would expect, for all of the shapes defined by a mesh. They look a little different, but the base color differs, and the shininess comes through.

The color is not applied to the spheres, which use some other shader, so that is expected.

Your call @david-bremer if you want to handle spheres the same way. I only did triangles and went out of my way to avoid lines (on purpose).