Sorry to dig up this old thread, but I have a related question.
I also want to apply a decal to an object by mixing two materials, but the mapping for the base material should be uv and the one for the decal xyz(planar). If I was using an image texture this can be easily done by using the projection node. In my case though, I want to use a procedurally generated c4d gradient as alpha (For instance to fade an objects material to different one at at a certain height.).
From what i understand c4d shaders are converted to textures at render time, so shouldn't it be possible to transform/project them as such?
Thanks for your help!