Draw multiple layers on Render Target

Hello guys,

So basically I want to draw with different colors on one Render Target.
I am getting strange results tho:

This is my brush Material set to Additive:

How can I prevent to colors from mixing? I need different Colors, because i want to blend different Terrain Textures based on what color a certain pixel is.
Basically I want to use the Render Target as a ID Map.

Your material is set to additive. Of course the colors will mix, that’s the entire point of additive: it adds the color to the exiting color value. If you are writing an ID map, using any sort of color blending makes no sense whatsoever.

Yeah I guess so. But using any other Blend Mode doesnt work with the painting on the render target…
Is there any other way to do this?

Hi Sensei, have you solved the problem? I have a similar issue here.