It is a "quick and dirty" bump map indeed. Correct bump mapping is a whole different ballgame, I don't think it's possible to derive a correct bump/displacement map from the texture map alone, using only shader math.

But I found it helpful for displacement mapping a stone tile floor, for example.

The pen is mightier than the sword. But if you literally want to have some impact, use a typewriter

My gallery   My freestuff