Compositing Mentor

What are Light Groups?

A Light Group is a render pass of a light (or a set of lights) in the scene, that is rendered in isolation from the rest of the scene’s lighting. All other lights are “off” and only the Light Group’s light is “on” and affecting the scene.

What is Refraction?

Refraction is the change in direction and speed of a light ray as it travels through or “Transmits” through different mediums, ie.

Why is Light Redirected during Refraction?

Light travels through different mediums at different speeds, depending on the density and make up of the medium. Examples of Mediums: Vacuum (space), Air, Glass, Plastic, Water, gases, etc. The change of light speed while passing from 1 medium into the next, causes the light to change direction when entering the 2nd medium. https://stoplearn.com/refraction-of-light/

What about non-ground plane mirrors?

For all oriented mirror planes, the same concept applies, you want to flip the world from the pivot point and orientation of that card along it’s normal facing angle. This is easier to do in 3D applications, but can be done in nuke with a little Matrix Inversion.

What is Albedo?

An Albedo Map is the base color or texture map that defines either the diffuse color or specular tint of the surface.