Nodes -- Normals from bump maps

General Forums Blender and CG Discussions
#1

I seem to recall a patch in the tracker for a node that can be used to make normalmaps from bump maps. Until it comes, though, I need some quick hack to mix some maps and get a normal out of it.

This is what I got after playing around some:

http://img91.imageshack.us/img91/6353/blendershotvh0.jpg%5Dhttp://img91.imageshack.us/img91/6353/blendershotvh0.jpg
http://img91.imageshack.us/img91/blendershotvh0.jpg/1/w1279.png

What gets me is the fact that the result is the same as the normal output from the texture node, but there could be a shorter way to accomplish this. If you know it, and you’re willing to share, please do :slight_smile:

So, how do you guys compute your normals when you can’t get’em directly?
http://img91.imageshack.us/img91/blendershotvh0.jpg/1/w1279.png%5D

#2

I asked the same question once, but I think it’s not possible to obtain a normal map from nodes. What I did was to bake those procedural materials, and then convert the generated image to a normal map in Gimp.

#3

You mean a final normal map? It’s not so hard to approximate Blender’s results. For simplicity, I’m using the Normal output of a Texture node here, but it works perfectly with the output of the noodle I posted above:

http://img357.imageshack.us/img357/7093/blendershotpa0.jpg

Your mix node is the equivalent to the normal strength setting, divided by… about three. When I tested, the equivalent to a normal strength of 1 was 0.31 in the mixer node. (I haven’t poked around Blender’s code enough to know how this works, so input in this matter would be appreciated.)

#4

Can you get “tangent space” normal maps with this technique?. I’ve been trying similar things but couldn’t get a tangent space normal map. Could get bump maps, and if you render them it works, although for GLSL we need tangent space kind.

The closer I got is the node setup below, and it doesn’t work with GLSL, only at render time. This makes the grayscale map a “normal input” of the first material, and I try to use the “normal output” of that material as a convertion to tangent space of the grayscale one.

http://www.uploadgeek.com/uploads456/0/normal_from_nodes.png

#5

Zelouille came up with a node setup for that some time ago.