Hi there, been looking everywhere for information about rendering tangent space normal maps in houdini, there are lots of links around but nothing that tells me how to actually render them.
Basically I want to take a normal map from zbrush and render it in houdini.
I got as far as rendering something that seems close to what its suposed to look like… I have the tangent space normap map and the N global going into a cross product node… I'm sure this is completely wrong way, the lighting doesnt come from the right direction… I've tried flipping rgb channels etc, but cant get anything decent. I think I need a node (or a combination of nodes) that converts tangent space to camera normal, but I havent a clue from here on.
At this point you will have to write your own VOP to do this- probably as VEX code. It's not too hard for an experienced shader writer, but a nightmare if you don't have a lot of experience in this, although perhaps there is some Renderman code somewhere for this that you could use as a starting point since VEX is so much like Renderman.
I would suggest making this an RFE- I would like to see the same thing available.
I would suggest writing out the Normal Map in Object space for the time being and just using this to replace the Geometry Normals in VOPs. It won't deform (or rotate) properly, but it will at least look good while still.
