Page 1 of 1

render normal maps from geometry

Posted: Wed Nov 11, 2015 8:59 am
by v-cube
Hello,

I was wondering, if there is an quick method to derive normal maps from geometry using octanes render channels. I tried vertex normal, geometry normal and shading normal but the result does not look like i would expect it ( more like a greenish picture in contrast to the more blueish regular normal maps I use)

can anyone give me a hand?

thanks!

Andreas

Re: render normal maps from geometry

Posted: Wed Nov 11, 2015 4:07 pm
by bepeg4d
Hi,
I have used this technique with z-pass for displacement, but you can do the same for normal map. You need a plane in the Z axis and a camera facing it, that's it :)
Here is an example in c4d and Standalone:
c4dOctane
c4dOctane
Standalone
Standalone
NormalGen.orbx.zip
orbx
(2.04 MiB) Downloaded 347 times
and here is the resulting texture applied in the normal pin of a metal material:
normal applied
normal applied
the generated normal texture
the generated normal texture
ciao beppe

Re: render normal maps from geometry

Posted: Thu Nov 12, 2015 9:32 am
by v-cube
Hello beppe,

thank you for your detailed answer!

I suspected that this should be possible and now I was able to identify why it was not working:

by the way, I use the Rhino plugin version, I always assumed that the geometry was supposed to be viewed/rendered from top (z-direction), however this does not seem to be the case, at least in rhino.
When rendering from top, surfaces which have an angle of 90 degrees towards the camera normal are rendered green not blue/cyan. After rotating the geometry by 90 degrees and rendering from the front view instead of the top view I got the expected result.
normal map.JPG
I will post this in the Rhino group...

best

Andreas

Re: render normal maps from geometry

Posted: Thu Nov 12, 2015 9:51 am
by bepeg4d
Yes correct, it depends because any app has its own axis system, for example, in c4d the Z axis is in the opposite direction compared to standalone, I forgot to mention, sorry.
ciao beppe

Re: render normal maps from geometry

Posted: Thu Nov 12, 2015 1:29 pm
by Bendbox
This is great to know, thanks!