Given the choice of either the slightly noticeable "edge of the cliff" look of the bump map or the really noticeable "concrete sheetrock" mismatched look of the procedural, I'll go with the bump map.

bagginsbill posted at 6:20PM Mon, 11 May 2020 - #4388818

When you take color data and desaturate it, hoping to create a bump map that makes sense, you accidentally pick up lighting in that bump map. This lighting produces gradients in shape that are not there.

Here's an example: I grabbed an eye wrinkle photo.

When I place a grayscale version of that on a sphere (left) you can see there are gradients where the light hits the convex curves at different angles of incidence.

The resulting gradient, when used as a height map (right), gives inaccurate curves, producing not convex compression zones, but terraces. There's a sharp rise at the highlight, and a dip on the shadow side.

I see these everywhere and they look like crap.

W10, Ryzen 5 1600x, 16Gb,RTX2060Super+GTX980, PP11, 11.3.740