Standard Shader Emission Value

Code (CSharp):

1. // First you want to use the API with multiple materials
2. // where 3 should be the index you want to use...
3. var materials = GetComponent<Renderer>().materials;
4. materials[3].SetColor ("_EmissionColor", Color.blue);
5.  
6. // Another thing to note is that Unity 5 uses the concept of shader keywords extensively.
7. // So if your material is initially configured to be without emission, then in order to enable emission, you need to enable // the keyword.
8. materials[3].EnableKeyword ("_EMISSION");
9.  

Oh and if you actually want to set it to black, then of course EnableKeyword is not necessary. In fact DisableKeyword in that case will make your shader run faster, because it will define out the math that deals with emissive surfaces, but of course the difference may or may not be huge depending on what you do, it may very well not be worth it to do that kind of optimization with switching enable / disable keywords.

 

This is only necessary if you actually want to animate emissive lighting. Do you want to animate emissive lighting?

 

As a starting point. I would suggest first trying it out in the material editor. So you can quickly see the results of changing the colors / textures assigned etc. This way you can prove to yourself or others that the rendering feature does indeed work.

Once you know that the rendering actually works and the content looks as you expect it, then it makes sense to script it. As explained above.