Convert normal map to bump map?

Does anyone have a good way of converting a normal map to a bump map? I am using GIMP but Photoshop would work too.

5 Answers

I've used this method in the past Scott, it's easy three steps

Based on Danny link (, adding step by step tutorial:

Answered with a tutorial:

There is also a software
Haven't tried that though as it needs a 32bit win:)

There's also NDO just launched version 2, integrated right inside Photoshop.

I just purchased the Shadermapper, it was like $40 and worth it. Befor that I was using SSBump and that did well for me it is freeware.