ZBrushCentral

Weird Black Artifacts In Normal Maps

ZBrush Usage Questions
#1

Hello I am TIO_MATT, we got 2 lincenses here in the department.
We are trying to use it in production.

I am having problems genereting the normal maps for my models.
I am getting artifacts ans weird black doots in some areas.
I have try importing several options of normal map:
World space, tangent an Smooth uv… with no feedback at all.

I am using 4k maps so I should have plenty of resolution.
I check my Uvs and they are correctly done.

Please any help would be more than apreciated.:frowning:

Thanks:

TIO_MATT

Attachments

Z_BRUSH_QUESTION copy.jpg

#2

I have notice some users had use Kaldera max plugin to fix this.
Is there an option to fix in Zbrush?
I am trying to use it in Maya.

THREAD:

http://www.zbrushcentral.com/zbc/showthread.php?t=17146&highlight=normal+map

Attachments

user_image-1084994561jfz.jpg

#3

Hi TIO_MATT,

Could you please send this portion of the dino leg to us for testing? The address to send it to would be [email protected]. You can send it as a zip file, and if you haven’t stored a morph target at subdivision level 1, we’ll need the original mesh as well.

Thanks!

#4

The surfaces were overlaping each other so I aply the smooth Tool option in the afected areas and extract again the normal map… and now because I fix the intersection on surfaces in tight places it generates fine…but…

I still got a big problem.

When I generate the normal map It generates fine but (in some areas) I had notice that the normal direction of the map go inverse and flips the other way, (in some areas) the sames happen if I extract the bump.

Some areas bump the right direction but some other areas bump to oppposite way, How can Z brush can get confuse generating some normal maps fliping the direction of the map??

Help, Thanks:small_orange_diamond:(

TIO_MATT

#5

The surfaces were overlaping each other so I aply the smooth Tool option in the afected areas and extract again the normal map… and now because I fix the intersection on surfaces in tight places it generates fine…but…

 <u><b>I still got a big problem.

When I generate the normal map It generates fine but (in some areas) I had notice that the normal direction of the map go inverse and flips the other way, (in some areas) the sames happen if I extract the bump.

Some areas bump the right direction but some other areas bump to oppposite way, How can Z brush can get confuse generating some normal maps fliping the direction of the map??

 Help, Thanks:small_orange_diamond:(
 
 TIO_MATT
#6

Did you try out the fix that I suggested in the other thread? http://www.zbrushcentral.com/zbc/showthread.php?t=17146

BTW, it might be beneficial if you stopped cross-posting the problem. It pollutes the board and makes it harder to keep track of the issues.

#7

There seem to be some problems getting a ZBbrush-generated normal map to render correctly in mental ray.

I don’t know if there’s a button that will match the tangents and lose the seams, I try fix seams in the texture panel ,…It fix it but not completly.

… looks as if the ZBrush tangents don’t match the Maya tangents, so the reconstructed normals will not be the same.

HELP!!!

#8

Could you provide examples, so that we have a better idea of what you’re experiencing?

#9

When I generate the normal map It generates fine but (in some areas) I had notice that the normal direction of the map go inverse and flips the other way, (in some areas) the sames happen if I extract the bump.

Hey bud I had the same problem
I found that it was the import of the objects in relation to their orientations etc.
Basically if you’re like me you will model with the front of the model facing down the negative Z plane in Maya.
I’m pretty confident in thinking that ZBrush how ever when you import the mesh WITHOUT FLIPPING and I fully suggest you don’t flip on import here looks down the positive Z axis. So when you draw it out you will be looking at your characters BUM instead of his/her/it’s face when you draw it out.

Export your model. Import it into ZBrush (WITHOUT FLIPPING) and notice what direction the model is facing when you draw it in the document.
Make your Morph target with the mesh facing in this direction and only rotate to paint etc.
When you’re ready to export, Move the model back to the same size/position I LIke to make sure I Can see the whole document and alt+double click in the document somewhere to scale it to fit the document
Then rotate it back to the exact same direction it imported in.
Go back to your morph target, and make your maps from this position.
Apply to the mesh in maya and this should give you a Normal Map with Mental Ray that works properly with a +'ve bump all over rather than in places.
How ever I’m now stuck with the same artifacts one other person is getting with their normal maps and whilst it’s all bumping the right direction I’m getting some horrible seams etc going on so will have to play with that this weekend.
I Hope this helps.
HK

PS I found that having in the preferences the FlipXY for the normal map produced a nicer result too at one stage when generating the normal map, but I’ve not restested this too much so don’t quote me on that :slight_smile: