Ratio of multipass textures compared to the color map

Question

I have 4 textures used in a multi-pass effect with the color map at the highest quality - which for this example is 512x512. Currently the Normal, Specular & Parallax maps are the same dimensions. The additional maps are taking a significant portion of VRAM. This seems incredibly wasteful.

My intention is to reduce the size of the multipass maps.

Color - 512x512 Normal - 256x256 (50% of original to keep enough detail) Specular - 256x256 (50% of original, once again to maintain detail) Parallax - 128x128 (25% of original as a blurred parallax could be beneficial - or so I'm told)

My question is, can I reduce the ratio's of the normal, specular & parallax maps further? Do these ratios seem reasonable? What ratios should I be using?

Thanks, Chris

Answer 1

tbh i'd want to maintain the normal map sizes and hammer down the colour map. All the detail in the final image comes from the normal map very little actually comes form the colour map.

Beyond that its texture compression all the way.