Adding Emissions to Custom Textures in Unity
Objective: To explain how to add an emission to a custom texture in your Unity project.
A emission is a texture that illuminates. In Unity the emissions work different between regular and static. For dynamic elements the emission will emit a glow where as a static element, it will actually illuminate areas using the built in GI system. This also works for both the Universal Render Pipeline (URP) and the HD Render Pipeline (HDRP).
Adding an Emission to a Texture
We only want to update the shell on the test tubes and nothing else. If we were to simply add an emission channel to the test tube it would light up the whole thing:
Firstly, navigate your way to the test tube texture and similar to my previous article “How to Alter Your Prebuilt Texture Maps in Unity” — https://christopherhilton88.medium.com/how-to-alter-your-prebuilt-texture-maps-in-unity-312ca9c819a4, let’s right click on the texture → ‘Show in Explorer’ → click on file and → ‘Open With’ → Photoshop.
Now lets load the selection, navigate to the top bar in Photoshop → ‘Select’ → ‘Load Selection’ → ‘Ok’. This is going to load the transparency on the entire object:
Add a new layer (grey) and we are going to fill in the inverse area. ‘Select’ → ‘Inverse’:
Now we are going to create a second layer and turn it black. Now everything in the white area will create an emission and everything in black will not and it will follow our UV map.
‘Save As’ → .png. Head back to Unity, we can now turn our emission back on and add in our new map. The only things that should be illuminated are the middle test tubes. Now we can go into the colour swatch and adjust our colours and play around with the intensity to get the desired look.