xNormal strange bake.
polycounter lvl 11
Hi all. First of all, sorry for my english :poly136:
When I import HP mesh and LP mesh into xNormal, select normal map i bake options, I get something like this:
Is this correctly baked normal map? Around my UV is some "artifacts" or something like this. This is some error?
And next question: If I have 512x512 UV Map for textures, can I make 1024x1024 normal map, and then scale it down to 512x512? Is that technique properly?
I made this stone block from Eat3D free tutorial, but i dont used model from the author. I made my own model, with a lot less geometry, and its look like that:
And this is, how it's looks on the LP model, rendered in 3D Max and menthal ray:
I know, i know, but UE3 dont want to run on my "wooden" PC
Only Unity can be runned on my PC, but Unity does strange thing with normal maps: add a lot of noise to the normal maps. I dont know why...
If you have 5 minutes, try to answer. And if you want, please judge my work.
Damian.
When I import HP mesh and LP mesh into xNormal, select normal map i bake options, I get something like this:
Is this correctly baked normal map? Around my UV is some "artifacts" or something like this. This is some error?
And next question: If I have 512x512 UV Map for textures, can I make 1024x1024 normal map, and then scale it down to 512x512? Is that technique properly?
I made this stone block from Eat3D free tutorial, but i dont used model from the author. I made my own model, with a lot less geometry, and its look like that:
And this is, how it's looks on the LP model, rendered in 3D Max and menthal ray:
I know, i know, but UE3 dont want to run on my "wooden" PC
Only Unity can be runned on my PC, but Unity does strange thing with normal maps: add a lot of noise to the normal maps. I dont know why...If you have 5 minutes, try to answer. And if you want, please judge my work.
Damian.
Replies
I dont know how to break smoothing groups in UV.
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You want hard edges that your smoothing groups creates to match with your UV borders, there are tools to do this automatically but I wouldn't rely on them, TurboTools has a feature in it for this, I think its called "smooth by uv shell"
And read this thread by Earthquake, some effort went into making it and it has some useful information
http://www.polycount.com/forum/showthread.php?t=107196
first of all: your low-poly model with applied normal map doesn't look too bad! so there is no real bad issue as far as one can see from your renders.
the "artifacts" around your normal map probably result from edge padding. this is helpful (for mipmapping i believe). so you probably don't have to worry about that. to be sure, post some images of your normal map with the uvs as an overlay.
what looks strange to me is the top right part of your normal map. those gradients seem pretty extreme to me. which parts of the model did you unwrap there? how does the render of those parts look like?
concerning downscaling of normal maps: it is possible in general and has some advantages, but you also have to remember one important thing:
scaling normal maps down is faster than baking them with antialiasing in xnormal and does basically the same thing. you would probably even find people to say that scaling down even looks better.
but, you have to run a normalization filter on your downscaled normal map before use. use the nvidia normal map plugin for photoshop with the normalize only option for example.
(and on a side note: you can't possibly unwrap a model to a UV map of a certain size. unwrapping always stores UV-vertex position relative to the image borders with no regard of the final image size. although, some modelling programs, e.g. blender, suggest that you actually unwrap to a certain size by making you select an actual image before unwrapping.)
I don't model that " two things" in ZBrush.
This is normal map without UV overlay:
And with UV overlay:
Scruples I know that wideo, and I know something about smoothing groups, but i don't know exactly, what are you talking about. But ok.
walkonsky thanks for positive opinion about my model. And i see it, nut when I'll making the prezentation of my model, for presentation on forum or something,and when I show this with "THAT" artifacts, people would say: hey what's wrong is with it.
Any practical proposition, to what to do with that?
I am aware of the fact that you should have hard edges on your UV seams. However, I dont really see a solution that doesnt introduce new problems for the type of mesh we see here. if you make the edges around the top of the mesh hard edges, wouldn't you get baking "errors" just like seen in this thread: http://www.polycount.com/forum/showthread.php?t=110549?
is there an easy way to avoid that?
@grafikPL: yes the overlay is exactly as i expected. when i understand correctly what you have written, you expect negative comments on the look of your normal map when you present your texture sheets with this type of "artifacts"?
They may be a little to big (set the edge padding value to a lower value in xnormal), but from my point of view they are not a problem per se. but lets see what more experienced people than me have to say about that.
Ray misses or overlaps caused by hard-edges are avoided by using a cage. Normally a baker uses the meshes normals to project the rays, so breaks in normals would result in breaks in the rays.
Heres a nice picture, also courtesy of Earthquake, you can see the cage in mesh B has gaps/holes, this is the default when you bake without a cage.
you harden edges in your mesh along the UV seams, but you use a cage as seen in A to have rays being cast without "gaps"?
Or do you have to have gaps in the cage where you have hard edges in your low-poly mesh?
sorry @grafikPL for hijacking, but this might even help you, too...
Correct, oh and be aware that this may introduce some distortion because the rays may not be getting cast directly away from the surface (theres always distortion but this may cause more in exchange for no gaps). Oh and distortion is also magnified by the distance the high-poly is from the low-poly
only too bad that i dont have time at the moment to experiment with that stuff myself!
thats the crux of being a hobbyist, i guess...
concerning your edits: yes, i understand that. I didn't think of that, but i see how that has to happen when the rays are cast.
But the problem about strange, big dots on top and bottom of the model is still existing.
Thats how it look in ZBrush (top of the model):
And tgat's hhow normal map looks after decreasing "Edge Padding" :
It's not a huge problem for now.
Edge padding stretches the border colors of the map past the uv layout(so it won't show up on your model) so that when your texture mip maps down to a smaller resolution, it doesn't blend into the background. This prevents seams from showing up when your model is using lower mips in game.
So crank that edge padding up, its a good thing.
also try to read up on some of the things that scruples and i have talked about in the last postings. hard edges on UV seams and using a cage for normal baking are the most important ones, i think. the wiki and earthquakes threads might be a good help here.
those "dots" are really severe artifacts that you should get rid of before continuing with the model.
P.S.: i cant see a zbrush render of the top of the model. furthermore, a render of the lowpoly with applied normal map would be much more helpful.
For now I'll texture it, and make a new model, maybe stone tiles, try to sculpt that in ZBrush, and make a new normal map. Hope that work.
Don't close this thread, maybe if I have some problems in nearly future, I'll post something here
Thanks for help guys
Here's what I've sculpted:
Here's the UV:
And here's my problem:
I don't change any settings in xNormal before baking. Any suggestions? It can be a low spec hardware? (cause I have very low spec PC). If you need any screens from settings, just tell, I'll post some.
Sorry for english.
heres some pics of what I've worked:
And that's what xN baked:
What I missed? And that problem I got when I baking any model from HP. Can I bake something like that? This orange model is 1 mesh btw.