Okay, so I am trying to make a texture painting set up, I am going to use it to draw footprint. I have a shader that is used to blit into a RT that draws into the RT where ever I click on a plane. If I use the material that uses that shader on the plane I see my texture drawn on to the plane. Cool, so far so good. However, when i set that RT to be used in another shader where I can combine the drawn texture with the surface texture the RT is just black. I set the texture on the planes shared material with the setTexture(). I think lerp between the surface tex and the RT tex by the RT alpha channel which is 0 where I am not drawing. What am I missing here?
Figured it out. I was using the blit(src, mat) so i wasnt actually rendering into the texture. Changed it to blit(src, dst, mat) and setting the dst to by objects material fixed it.