This article will be covering the “Emission’s Channel” also known as “Self Illuminance”. Emissions are basicly light coming from an object that isn’t using a light source but rather grabbing light data from a texture or color. This means that if you set an object’s shader to utilize emmisions, it will be illuminated regardless of any external light sources.
In external 3D Modeling software such as Maya or Blender, you can “Bake” your light sources on the model so that Unity can read data on where to illuminate light.
This is a texture/color map that was imported from Maya with the light sources illumination already baked in. You can see the lighter areas near the edges where the texture is saying the light shines the stongest.
These emmisions are very performance friendly and if used correctly, could even go a long way into increasing the general performance of your game as you become less dependant on other forms of lighting.
Notice the difference with the lighting on the rim of the glass. The example above is using the “Texture Map” shown earlier that includes baked in lighting amd the example below has no texture map at all.