Visual aspect: colors + light effects?

[fhb1990]

The geometries are now black. It does not look nice. It would be nice if it looks nice. Also, lighting effects could perhaps be added to help with the 3D visualization.

[fhb1990]

Colors for different CityObject types have now been hardcoded.

I would like to implement lighting. This would require that the MeshBasicMaterial is changed into either MeshLambertMaterial or MeshPhongMaterial, for these mesh materials reflect light. However, I haven't yet gotten this to work.