Now I add the GND4 bump map, which was made from the color map. It is not a straight gray-scale conversion, as there was some levels adjustment, but by and large the features found in the color map are also on the bump map.

The original photos obviously did not have the light straight on. The result is that the highlights are slightly to the side of the original bumps on the original human subject.

When these highlights find their way into the bump map, they create ridges where there should not be any, and leave other areas flat where there actually should be bumps and ridges. And freckles become divots.

I also added a Blinn node to produce real 3D speculars that pay attention to my light source. These speculars do not show up right, because the bump map is wrong.

This looks horrible, like a disease. I never use this bump map. Ever.

Again, click for full size so you can see the details. I'll stop saying that now. grin

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Renderosity forum reply notifications are wonky. If I read a follow-up in a thread, but I don't myself reply, then notifications no longer happen AT ALL on that thread. So if I seem to be ignoring a question, that's why. (Updated September 23, 2019)