It should be possible to also bake a UV map alongside the impostors, based on the relative angles between the ray cast from every impostor pixel and the surface normals of the triangles of the model being baked. That UV map should double the memory requirements. However it means that you can do dynamic lighting, by sampling the lights at the impostor's origin in the world, and building up a list of tuples of vectors containing things like color, angle, spread, direction, intensity, and applying those to the UV map - and ultimately to the impostor sprite, similarly to bump maps. This would allow the impostors to be well-lit, although I'm not certain how you would account for shadows or highly directional light sources.
I also wonder, to what extent can this method of impostor rendering actually replace ordinary rendering? There is clearly a tradeoff between triangle count and sprite memory. It is possible to stream in higher res textures to replace low-res stand-ins. How feasible would it be to ship GPUs with ridiculous amounts of memory, that are optimized primarily for impostor rendering?
It should be possible to also bake a UV map alongside the impostors, based on the relative angles between the ray cast from every impostor pixel and the surface normals of the triangles of the model being baked. That UV map should double the memory requirements. However it means that you can do dynamic lighting, by sampling the lights at the impostor's origin in the world, and building up a list of tuples of vectors containing things like color, angle, spread, direction, intensity, and applying those to the UV map - and ultimately to the impostor sprite, similarly to bump maps. This would allow the impostors to be well-lit, although I'm not certain how you would account for shadows or highly directional light sources.
I also wonder, to what extent can this method of impostor rendering actually replace ordinary rendering? There is clearly a tradeoff between triangle count and sprite memory. It is possible to stream in higher res textures to replace low-res stand-ins. How feasible would it be to ship GPUs with ridiculous amounts of memory, that are optimized primarily for impostor rendering?