Applying decals / textures to uneven surfaces runtime

Hey, Im looking for a method / a way to apply textures to uneven terrain during runtime, for example like applying a paintball splat along spherical object.

I am not looking for applying a texture plane along the normal though. Im okay to code it all myself,(unless its to do with shaders :L, guess i gotta learn them one day xd ) im just looking for a way to do this :slight_smile:

how to solve below error it comes when i build my android phone
‘UNITY_PASS_SHADOWCASTER’ already defined at line 309 (on gles)