Changing the relative position of the light will only have an
effect if you are using #point or #spot lights. These are
computationally more expensive than #ambient and #directional
lights, so it is better to avoid #point and #spot lights if
You can adjust how the shader(s) on the model react to light,
by changing the colours associated with the .ambient, .diffuse,
.specular and .emissive properties af the shader.