Is there a way to have something like a geometry with a constant shader which is not afffected by lighting but it contributes to GI(casts GI) and it receives shadows from other geometry (shadows which should be affected by GI)?
Lets say I got a grid textured with satellite imagery and now I want to build some geometry on it (eg. buildings) and I want to create GI lighting conditions in a way that it gets as close as possible as it was captured on satellite imagery. So, I dont want those satellite textures (on a grid) affected by the lighting, the lighting should serve just to light the objects which I'll be putting on the grid. However, I do want the grid to receive shadows and to cast GI on other geometry.
I'm aware there's a way to do this later in compositing with passes, but I just can't afford to go back and forth between hou - comp software cause it's a huge project and I have to constantly check lighting conditions as I'm building geometry.
Perhaps if there was a way to modify a shadow matte shader so that it displays results instantly on rendering (rather than just outputing black colors with alpha values) I would be able to apply this shader on a duplicate of my grid geometry while the original grid geo would just use a constant shader.
