To renormalize, or not renormalize, that's the question.

[HP]

I think this is still a bit of undiscused grounds around here.

Now, if I am not mistaken, if you have a mesh with only one smoothing group, and you use it to bake a tangent normal map, then the normals from that normal map will make up for the weird shading you'd get from the lack of smoothing groups on your LP.

Now, correcty me if I'm wrong, but if you renormalize your normal map, in theory it will loose the shading and your LP will look wrong, still some people say you should always do this, even when your LP shading is depending on your normal map.

I'm a bit confused in regards to this, and would like to think your opinions on this, do you or do you not renormalize your normal maps, and why?

Edit: mmm, this would probably be better in the technical discussion. Can a mod plz move it? Sorry for that.

Frankie

What do you think re-normalizing does to the normal map? I think it just make sure all the vectors components add up to a value of one. Most of the time it shouldn't need doing as it comes out of the bake ok. If you decide for whatever reason to hand paint or blend layers on top of the images you may need to re-normalize it. If it looks ok when you test it in game then it probably is ok.

Ben Apuna

Yup blending layers will probably need a re-normalization.

A bake should come out normalized by default.

Normalizing shouldn't kill the "shading".

I've heard that oftentimes the shader in engine will normalize the normal map stuff again anyway. You should talk to your shader author, or programmer to confirm best practices for this kind of thing rather than assume one way or the other.

Peris

I have never renormalized, why should I start doing it?

MM

what is re-normalize or normalize.


EDIT

nvm, i had to look it up since i never done that before.
i dont see any situations where i would need to normalize a normal map.
if anything, you would only want to normalize any manually edited/painted part of the normal map.

if you normalize a map baked from highpoly u will get shading errors.

Ben Apuna

Here's some explanation from the wiki.

More info in the What's the point of flattening and renormalizing normal maps before saving them? thread.

MM

if you are blending an overlay layer, just level your overlay normals blue channel to 50%

metalliandy

I always normalise any normal map that has been edited in any way (even when just baking a x2 res. and resizing)
If the shader doesn't support automatic normalisation (most engines do), then you can get things like scintillation etc.

You should never have to renormalise a straight bake, because it should be baked with all the correct values already but as soon as you add an overlay then it can change the vectors to a value that is incorrect.
If you are losing the shading of your normal map after normalisation, then something is really wrong with the baker in whichever application you baked with, or the package you are normalising with is broken.

Ace-Angel

Question, would creating a detail map which has been baked, and mixing it with another baked normal need to have the final output of the shader for detail AND normal map normalized?

What I mean is this

metalliandy

Ace-Angel wrote: »

Question, would creating a detail map which has been baked, and mixing it with another baked normal need to have the final output of the shader for detail AND normal map normalized?

What I mean is this

Only the final combined normal map would need to be normalised.
Doesn't UDK normalise maps automatically anyway?