Normal Map Deepening
Use multiple layers to augment baked normal maps with real depth in your overlays. Please don't hot link this image, my host complains.
Base diffuse map. This is a flat color with some slight color variations, with the light bake from the high poly on multiply mode.
Base normal map. This is the flat normal bake from the high poly.
Realtime preview of these two maps in effect.
Fabric overlay texture, fully opaque.
Fabric overlay texture, with levels adjusted to show only the deepest pits.
Save a copy of the dark pits, to put on multiply mode in the specular map. This keeps the crevices from shining, which gives away the illusion of depth.
Fabric overlay texture, put on overlay mode on the diffuse map.
Fabric overlay texture, run through the nvfilter at scale of 3. The blue channel was halved in levels, then the whole layer put on overlay mode on the normal map.
Realtime preview of these maps in effect. The texture looks a bit too much like a stamp right now, not enough volume.
I took the deepest pits layer and put it on multiply. I also colorized the layer first so that instead of black, the pits were a dark maroon. It only makes a small difference in the diffuse map.
I took the deepest pits layer and ran it through the nvfilter with a scale of 3. Then I halved the blue channel and put the layer on multiply mode on the normal map.
Realtime preview of these maps in effect. The texture has a lot more volume now.
Here's the original tutorial image for reference.