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Some questions about normal map

Posted: Mon Apr 05, 2010 2:19 am
by Krisonrik
I'm currently using zbrush generating normal map. The result isn't very obvious on render through octane somehow. I am wonder whether I'm need to correct my setting in regards to generating the normal map through zbrush. Also, is it very different when we talking about normal map in unbiased render compare to the tangent normal map people use as bump map in game, you know as a better version of bump, or am I missing something and should use bump.

Re: Some questions about normal map

Posted: Mon Apr 05, 2010 4:17 am
by Son Kim
Good question and maybe i'm doing something wrong also, but the normal map isn't doing anything when combine with a diffuse texture - maybe its normal(no pun intended)?

Re: Some questions about normal map

Posted: Mon Apr 05, 2010 4:57 am
by James
Son, what kind of lighting do you have on the object? It looks rather diffuse, afaik diffuse lighting isn't going to show up normal maps...

Re: Some questions about normal map

Posted: Mon Apr 05, 2010 5:08 am
by Son Kim
James wrote:Son, what kind of lighting do you have on the object? It looks rather diffuse, afaik diffuse lighting isn't going to show up normal maps...
you sir are correct - so i'll need to use a glossy material to see normal maps. diffuse+normal map showing "bump" only works in game engines. BTW what other kind of lighting can one use beside diffuse? :?:

Re: Some questions about normal map

Posted: Mon Apr 05, 2010 12:56 pm
by Chris
Yes you have to put it on a glossy material to see it clearly. Normal maps are the same as used in game engines. There is differences between normal maps when it comes to axis alignment. You have to remember to flip one of the axis in Zbrush before you export the map, cant remember wich now. Il check it out.

Re: Some questions about normal map

Posted: Mon Apr 05, 2010 2:09 pm
by Chris
Heres the correct settings for making normal maps inside Zbrush that works within Octane:
zbrush_normal_settings.png
zbrush_normal_settings.png (5.58 KiB) Viewed 3932 times
Remember to Flip V before you export the normal map:
zbrus_flip_v.png
Cheers

Re: Some questions about normal map

Posted: Mon Apr 05, 2010 2:52 pm
by BroAugustine
Another thing regarding normal maps is that when present, the bump maps have no effect. Is it possible to get both to work together in the future?

Re: Some questions about normal map

Posted: Mon Apr 05, 2010 2:53 pm
by radiance
BroAugustine wrote:Another thing regarding normal maps is that when present, the bump maps have no effect. Is it possible to get both to work together in the future?
no, normal maps have precedence, when used, bump maps are ignored.
i'd advise against this, as it will make the render extremely slow.
you should try to stick to normal maps only.

Radiance

Re: Some questions about normal map

Posted: Tue Apr 06, 2010 7:40 pm
by Krisonrik
So the green channel should be flipped? I was never good with normal maps. hahah

Re: Some questions about normal map

Posted: Tue Apr 06, 2010 8:35 pm
by Chris
Yeah flip the green channel in Zbrush before you export