Bump Map normals sometimes don't work...

I have found that when a bumpmap has too great a contrast from pixel to pixel the rendering engine will render it as 0.

For example, have a one sharp black shape surrounded by a white shape. The border between the two has no gradation or AA. The rendering engine will not render the black shape lower then the white shape.

As a workaround I need to blur the texture. I use .01, but I don't believe it's really any lower then 1.0. Consequently, in the final render, the sharp edges of the paint (for my upcoming rusty paint texture) will look a little like putty, not sharp paint flakes. The bump map looks ok, and I think I'll get the right result from Lightwave, but with Filter Forge's rendering engine it appears that the dark/light borders are rendered wrong.

Probably you're trying to connect something with very hard edges, like a B/W checker, to a Height imput -- right?

If that's the case, then the black result you see is absolutely correct, since FF doesn't generate any slopes automatically -- you have to make the slopes manually.