Our game is using pre-rendered isometric graphics with normals and dynamic lighting. We want to dynamically add a height fog effect based on a pre-rendered height map, so that low areas get the most obscured by fog.
With an emissive material we could blend the fog with the base color directly, but with normals and lighting we need to do it in post process.
Is there a way to expose a materials height map (that is not connected to the material node) to a post process material? In other words for every pixel in screen space store a height value that is not used until post processing.
I’m also interested in hearing about other methods to achieve the same or similar effect.