Function createVehicleMaterial

The one material every vehicle part shares. Per vertex: color (own colour) and vstyle (paint, glow, finish). Per instance: vehicleLook (tint rgb, heat) and vehicleStates (wetness, snow, burn, damage, from threejs-weathering's InstanceStates). The tint goes in through colorNode, before the weathering states, so snow stays white and ash stays grey on any paint. Painted surfaces are metallic paint under a clear coat (lost under snow, ash and heavy damage); finishes give glass, chrome, brushed stainless steel (anisotropic, brushed along the vehicle) and rubber. Damage also dents the body.