I still don't get the point of normal maps versus bump maps.

Please don't compare them to displacement maps. I understand that normal maps are faster/cheaper than displacement maps and you give up the actual movement of the surface.

The same exact thing can be said of bump.

Please, somebody besides me, show a comparison of bump versus normal, like this image. (Click to enlarge)

The two balls on the left are bump mapped. The two on the right are normal mapped. (I got the bump and normal from Filter Forge)

The upper ones have 4 times the amount of bump than the lower ones. Notice that the normal map has gone screwy - you cannot manipulate the bump depth with a normal map. I said this in the beginning - normal maps are inferior because you have no control over the depth at render time.

To my eye, as well, between the bottom balls, the bump-mapped one looks better. It tolerates the texture filtering whereas the normal map doesn't do so well. (Texture filtering results in de-normalized vectors.) If you turn off texture filtering, you get total crap with fine lines like these.

As for performance, I ran this render over and over with 4 threads (one in each quadrant) and the bump map balls finished way before the normal mapped balls.

Does anybody actually have data and renders to back up the claims that normal maps are better quality, give more control, and are faster to render? Because my experience is that bump maps are the winner in all three categories.

By the way, there is a non-standard issue around normal maps. Some place the y-component positive is up, others down. For Poser, I had to invert the green component to get it to render correctly. Thank goodness for nodes.

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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)