My Introduction to Indirect Lighting
Continuing with my Survival-Horror inspired scene in Maya, I’ve started experimenting with different lighting techniques. Having up until this point only utilized simple direct lighting setups to light my scenes, I’ve now moved on to learn more about how to use “Indirect Lighting” to improve the look of my renders.
“Indirect Lighting” occurs when light that is emitted from a direct source (A “Light” in Maya, for example) bounces off of surfaces in the scene. It is from this behavior that this kind of light can also be referred to as “Secondary Light”.
When the light contacts a surface it can take colour from this surface along with it. This newly coloured “secondary” light then lights other objects in our scene.
The first type of Indirect Lighting that I’ve started to play with in Maya is known as “Global Illumination”. Here light sources are created, and set to “Emit Photons”. These “Photons” travel from the light source and bounce around our scene just like light does in the real world.
It seems that Global Illumination works best if you separate the Direct and Indirect light sources within a scence. Leave the “Direct” lights to provide basic light on objects and cast the scene’s shadows, and create seperate lights that will emit the Photons required for our Global Illumination.
Therefore we select our “Secondary Light” sources, set their standard “Intensity” to zero (So they do not cast any direct light), but enable “Emit Photons” instead.
Here are two renders of the same scene – one with Global Illumination enabled and one without.