Problem with normal map baking
polycounter lvl 12
Been stuck on this problem when baking with normal maps.
You can see the problem in this pic. Its going weird at that front face and a little further back.
Was hoping someone can tell me what causes these problems. I'm using Maya and baking my maps inside of Maya.
You can see the problem in this pic. Its going weird at that front face and a little further back.
Was hoping someone can tell me what causes these problems. I'm using Maya and baking my maps inside of Maya.
Replies
And here's the low poly with the wireframe.
and here's the normal map I'm getting for this part. UVs aren't final. Just testing.
Hardening edges can help reduce artifacts, but if you are going to harden an edge, you should also split the uv's there.
That's the short, short version. For the long version, check out the thread cptSwing posted, or check out the polycount wiki, normal map section.
Anyway, using hard edges here and there fixed all the problems I was having.
I tried that. Here's a comparison pic. One on the right was triangulated before I baked. For some reason it looked terrible.
Keep in mind your quad mesh is actually still made up of triangles, the lines joining them are simply hidden and usually re-evaluated whenever you move a vertex, which is the reason behind triangulating them before export or import, because different programs may triangulate the mesh differently.
If the vertex normals are changing when you triangulate you can actually freeze the normals before triangulating to prevent this.
I you want to see the hidden triangles, you can go to Display>Polygons>Face Triangles, with your object selected.
If you're sending your mesh to an external app like Xnormal to bake you should triangulate before you do that as well, because xnormal may triangulate your quads in the opposite order and give you "X" shaped smoothing errors.
Nothing the OP is showing here looks like a direct result of triangulation though. Even with a synced normals workflow, normal map display isn't perfect, especially when you have shading on faces that are angles greater than 90 degrees like the OP's big problematic area there. Normal maps can't really account for such a steep angle.
But yeah, simply setting all of your uv borders here to hard edge will likely fix your issues. There is a maya script that will do this in the thread linked above.
You can also bevel some of your edges there to soften out those hard angles.
The bake looked fine after that, both in Maya and Marmoset. Now with the piece if I turn it to either quads or tris in maya, it still bakes out and looks good in Maya and marmo.
I know I probably shouldn't obsess so much over some of the smaller smoothing areas and everything, but I'm not a fan of having to fix up normal maps in Photoshop. I'd much rather just bake it and be done with it.
Ah yeah, that worked as well. Thanks for that, and for all the other write-ups you've done recently on this subject. As that guy said in the other thread, you really are the Dr. House of polycount.
I tried with other meshes and I get the same problems, although the artifacts look different depending on the mesh.
A. stepping type artifacts, this is usually what Maya opts for
B. noise, or dithering, which I think is what Max does and I prefer a bit honestly.
But I think you're probably over-thinking it a little here. Will this sort of thing show up when your asset is textured, in game, compressed etc? Probably not.
(unless I'm mistaken as to what your issue is entirely).
If that is what you're talking about, yes it is pretty much unavoidable when dealing with normal maps that have heavy gradients, because its simply a bit depth issue, there aren't enough colors available in an 8bit/per channel image to render a smooth gradient without stepping or noise.
It looks like in general you're getting some smoothing errors here. Toolbag isn't synced with Marmoset, so you won't be able to get away with the same sort of smoothing as in the maya viewport. With a simple box like this, hard edges on all the edges with uvs detached is going to look best(in marmoset or any game engine that isn't synced with a specific baker).
Detaching the top and bottom faces entirely/using hard edges there will improve it as well if you've got everything connected.
I'm guessing it would be hardly noticeable once the diffuse and proper specular are done, but are these sorts of artifacts just unavoidable in your opinion?
Just a guess, but if you want to be double-sure that it's not an issue with your bake, try baking again using a cage (if you didn't already). It looks ALMOST like ray-fails.
Yeah, sorry. Not used to using maya terminology when talking about bakes.
dirigible - was pretty sure I knew what you meant, just wanted to make sure. Thanks.
Just to be clear his last pic is heavily edited in photoshop to point out the extremely, extremely minor artifacts he's getting. The shot above that is the baked result, which you can't really see the issues with the naked eye(well I can't atleast).
So you'll be on a wild goose hunt if you're trying to debug his edited image, the last image he posted. =D
Thanks for the heads-up
I don't wish start new thread beacause have almost the same problem.
When I bake normal map some edges (on a low poly model) are still visible. I'm use Maya (2016). When I export model to Unity this edges still visible also.
The model was softed with "Soften Edge".
Here is few pics that will show problem... (low poly + normal map)------->
This pic shows part of hi-poly------>
This pic shows normal map and UVs in Maya-------->
And this nMap from xNormal------>
All nMaps are 256x256.
Not all edges visible, only some...
As I understand this problem is not from nMap but from edges.
I spend 3 days for tries and info but nothing.
Thanks for help.
(sorry, I don't know how to make photos with one spoiler)
Just tried separately set each UV island to Soft (that required for smothed surface). No changes--strange edges still here.
When you bake, try separating each UV island into a separate smoothing group. That usually fixes baking issues like that for me. There are usually scripts that do that for you.
While this works and is quite a popular "fix", it is important to remember that it is by no means necessary. When placing a hard edge, one has to make sure that it sits on a edge that is also a UV border. But that does not mean that all UV borders need to be hard (as this would be a waste and may introduce issues in unwanted places).
Good luck !
As pior said, it's not absolutely necessary to have hard edges at UV seams (it can cause issues with mip mapping in some cases), but for the purpose of troubleshooting it might be easier to harden all UV border edges until you've solved your problem.
Here's a script by Jonathon Stewart that sets hard edges to texture borders, in case you're sick of doing it manually.
It's look like (not 100%) this problem from http://polycount.com/discussion/107196/youre-making-me-hard-making-sense-of-hard-edges-uvs-normal-maps-and-vertex-counts/p1
But in my case not all edges visible. And I tried ABC methods.