ZBrushCentral

Normal-Map / Displacement-Map Bug

ZBrush Usage Questions
#1

Hello,

I recently posted a problem with a displacement-Map, but I didn’t get an answer to my problem. So I tried and tried and didn’t get the trick to solve the problem.
Now after some time of relaxing, I tried to solve the problem with normal-maps but I got the same error of the result.
Yesterday now, I made the normal-map with xnormal, and the error is gone. So it must be a bug when creating the maps in zbrush. Did anyone else have sinilar problems?

Here my pics:

  1. The relevant part of the normal-map, made in zbrush
  2. The result using the zbrush-normal-map, rendered in poser
  3. The result using the xnormal.normal-map, rendered in poser

The same results, I get in other programs or in the 3d-view of xnormal. Also I have the same eroor, as mentioned above, when using displacement-maps, made in zbrush.

Thanks for viewing, hope to get an answer.

mawag01

Attachments

ZBrush Bug.jpg

ZBrush Normal.jpg

XNormal Normal.jpg

#2

do you get similar errors with different meshes. or just this one?

#3

Hello, it’s my first low-poly-project, it’s my first subtool I baked maps.
And it was rather frustrating till I found xNormal.

But I think, xNormal now helped me to find the reason of the error: Backfacing Meshparts, which don’t touch the front-mesh in the lowest resolution, but only touch them a little bit in the highest resolution:
When I bake normal-maps in xNormal, not discarding the option “discard backface-hits”, I get the same errors.

But: My lowres-mesh is clean and nowhere a backface can be seen when hitting the “Display-Properties - Double” button in ZRemesher.
But in the HR-Mesh (Subdivisionlevel 6) it’s nearly not possible to see backfacing parts of the inside which only touch the outside-mesh and don’t go through the outside mesh.
To see these only touching and not going through the frontside backfaces, you need to turn on “Draw Polyframe”. But the mesh is in Level 6 so dense, that you can’t see these problematic areas.

That’s again a new experience, which I made and which did me cost much time by trial and error.

But perhaps, it can help someone else with similar problems.

Or does anyone have a good resolution to see all theses backfacing meshparts which only touch the frontmesh in a higher resolution?

It would help to find them all and correct these problematic areas.

mawag01

#4

Did you account for the zbrush-baked map being flipped vertically ?

#5

it does look to me as if you’ve got some serious distortion in the lower levels of the mesh, so you’re on the right path with your explanation of the problem I’d say.

ZBrush isn’t the best thing to use for normals anyway - nearly everyone use xnormal as it yields better results :slight_smile: