Altering Emission Maps

Gerald Clark
2 min readNov 11, 2022

In the previous article, I covered how to simply change the color of a texture map. In that scenario I was covering how to do this with a base map. This article will cover how to make/alter an Emission Map.

If you check out this test tube in the project view, you’ll see that it doesn’t even have an emission map! My goal is to get the tube to “glow” so to speak and be able to change what color it glows.

No Emission Map!?
Original Base Map Texture

You can see that the pale, green color on the base map is what controls the color of the tube’s glass. I want to change that to be white and everything else black.

Emission maps require 2 colors. White and black. Everything white will be what emits and everything black is ignored. This is technically an emission map.

I dragged the base map into GIMP and created 2 layers. I simply traced the green areas and filled them accordingly. The green part: white. The rest: black.

I made two layers because of the way the fill works. The top left has the white area with the black circle in it would fill entirely otherwise. There is probably a less time consuming way to do this. There are lots of tutorials online about how to use GIMP effectively and efficiently.

After this I simply merged the two layers and the result is!

Export this into Unity, and assign the emission map to the test tube’s material! CHANGE THE COLOR TO WHATEVER YOU WANT AND VIOLA!



Gerald Clark

Father Game Developer Music Composer Sound Designer