Normal map with H11

[thinkinmonkey]

Hi all,

I'm working on my project also with ZBrush in order to create normal maps and to render all in Houdini 11.

Rendering with the Mantra Surface Material from Material Palette, I get this:

That is really inexplicable for me!

So, after a search, I got a guide to manage ZBrush normal map in the bottom part of this page: Working with VOPs

So I tried to create a simple shader like they suggest, even if I had problem to create the "Invert with the negate option", this is the network with its result:

Then I tried to connect the normalize node avoiding the rest:

That is much better than previous renders, but If I change the camera position, strange renders result, because there's no transformation on camera space.

I've attached the scene and the normal map texture if you want to test by yourself.

So I'd like to know what's wrong with all of that and how I can go out from that.

Thanks in advance.

nmapTest.zip

[smaugthewyrm]

Hi all,

I'm working on my project also with ZBrush in order to create normal maps and to render all in Houdini 11.

this tutorial helped me.

http://learning3dfromscratch.blogspot.com/2009/06/zbrush-to-houdini-texture-and-normal.html

he used this post from our forums to build it:

http://forums.odforce.net/index.php?showtopic=3775&st=12&p=28418entry28418

Edited January 18, 2011 by smaugthewyrm

[thinkinmonkey]

hi smaugthewyrm,

thanks for your links, I'm reading them hoping they will help me, but they are not related with the problem (or so it seems to me) about how H11 renders normal maps with its Mantra Surface shader.

So my need to know remains!

[Keating]

Hey Guys, when you're working with normal maps from Zbrush inside of Houdini, you need to generate the normal using the 'flip green' option checked.

Also, there is currently a bug in the mantra surface shader which is easily fixed. Dive inside and go toward the top, you'll find a node called Normal Convert. Dive inside this node and go to node labelled ConstantInvertY.

Change the float value to 1 1 -1. This should solve all of your zbrush-> Houdini problems with normal maps. ( This is for world space normal maps, by the way, tangent is not yet supported by default )

hi smaugthewyrm,

thanks for your links, I'm reading them hoping they will help me, but they are not related with the problem (or so it seems to me) about how H11 renders normal maps with its Mantra Surface shader.

So my need to know remains!

[thinkinmonkey]

Hi Keating,

I'll try what you suggest.

And to keep it more clear, if you speak about world space normal map (reddish/greenish texture), I should calculate them in ZBrush in that space, not as normally I do (tangent space-blueish texture), isn't?

That could explain the strange renders.

I hope the tangent space will be supported in H12, they are very important for everything is animated (deformed) by bones, but for now I'm lucky: only static and heavy stones for my project!