Actually, a 50% value in the blue channel indicates a surface 90° from flat. A black value in the blue channel would indicate a surface 180° from flat: a back-facing surface. But that doesn't really happen in a tangent-space map. In practice, blue values are always at 50% or higher.
I think you are misunderstanding what the blue channel does in a tangent space normal map. Red and Green indicate changes in light direction which will give the impression of the surface going up or down. If you invert these two channels details will also appear to invert from going inward to outward and from outward to…
It does seem weird that half of the blue channel's range would go to waste... but object-space and world-space maps actually do use the whole range, since they aren't surface-relative.
the real question is why you are using the nvidia filter. If you cant afford a copy of crazybump, there is shadermap and also xnormal has a height to normals tool and photoshop integration to boot. if you want to layer detail I suggest you do it manually instead of using a tool where you have limited adjustability.…
Its a very interesting comparison image (between crazybump and Rod Green). some observations: I'm left wondering about how the lighting 'falls off' on the shadowed side of the sphere. the crazybump version is overall very intense (the flowers) while the RG version (ron green) seems more natural, significantly less…
My workflow on some smaller objects right now involves creating minor details (electrical sockets, small switches, bumps) as a 0-255 grayscale height map with a 128 midpoint that I normalize with the Nvidia filter and overlay on a baked normal from max that I use to capture general surface curvature. Right now I'm fighting…