Voxel Materials

[ClarkThyLord]

Add the ability for Voxels to define their own material attributes per face, such as metallic, roughness, emission among others

• [x] metallic
• [x] specular
• [x] roughness
• [x] emission
  • [x] energy
  • [x] color

[ClarkThyLord]

Voxels can now define their own metallic, specular, roughness and emission energy / color material through their respective properties, reference the voxel schema. However, these properties are not on a per face basis, instead they're applied to all faces of the voxel, but this will likely change to a per face basis in the future. Note, that if a voxel has a VoxelSet material defined it won't apply it's own "individual" material

[ClarkThyLord]

I've decided to keep the current implementation, I can’t think of any reason as to why I’d want materials on a per face basis, and implementing it just because would only add overhead when creating voxel content. So, unless I or someone else convinces me it's worth implementing, materials will be applied on a per voxel basis. But other than that, voxel materials have been fully implemented.