The Power of Indirect Multipliers in Unity
So you went through the process of baked lighting and you find that objects in your scene aren’t quite as bright, or maybe they’re too bright or disproportionate! Whatever the case is, baked lighting can be rather time-consuming and just the thought of having to re-bake everything all over again sounds exhausting. If you run into this situation, Indirect Multipliers might just be your new best friends!
Objective: In this article, you will learn a way to manipulate your scene’s baked lighting without having to re-bake everything.
Table of Contents
Note: You may want to check out these articles:
Here I explain Baked Lighting and a way to optimize it
Optimize Baked Lighting in Unity
Baking is a process that extracts and stores information from the geometry of an object, which can then be used to…
and here I go over a comprehensive beginner's guide to light probes, which benefit greatly from indirect multipliers.
What is an Indirect Multiplier for Lighting?
An indirect light is a light that bounces off surfaces in the scene. It can be used to simulate a broad range of lighting conditions, from the warm glow of candlelight to the cool blue tint of moonlight.
The indirect multiplier controls how much bounce light is produced by the surface. A value of 1 or higher means that more bounce light will be produced, while a value of 0 means less. Values in between these two extremes or beyond produce various levels of bounce light. By manipulating the indirect multiplier, you can tweak the lighting in your scene, even baked lighting, without having to go through the process of re-baking it.
How to use Indirect Multipliers in Unity
Indirect Multipliers are found on your light sources in the Inspector.
Let’s take a look at this simple scene, everything appears to have a warm color right?
Well, actually these are the real colors of this room.
The reason why everything looks warm is that there are two baked spotlights pointing at the red floor and the indirect multiplier on them is causing the light to bounce from the floor onto the rest of the room. Of course, this is also complimented by a set of light probes that are spaced within the room.
For this example, I overshot the values of the multipliers to make the light bounce as apparent as possible.
Now, let’s take a look at what happens when we decrease those values to 1 instead of 50.
You can still see some of that bounce lighting on the blue walls where the Spotlight cone is intercepting, but otherwise, the room is very dim. You can tell the difference Indirect Multiplier make easily, even a room with few light sources can be transformed by using them.
Note: If you’re having trouble with Indirect Multipliers, you may need to go to your Lighting window and set Directional Mode to Non-Directional.
Indirect Lighting, which is essentially the bounce light coming off of surfaces, can be complemented by Light Probes. By using the Indirect Multiplier values provided by light sources, you can tweak baked lighting in your scene without the need to re-baking everything again.
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