Mudbox Painting Problem >:(

#1

Hey guys,

                                         When painting or projecting in Mudbox I get these  weird pixels that get stretched within small squares in the texture.  It’s like Mudbox is painting in dozens of small tile                       squares scattered all over the texture and I end  up with some of the squares stretched. ??????                     

                                         Images speak a thousand words so I have attached a  screenshot ([b][u]AND a FBX file of my model[/u][/b]), so you can see  for yourself:                     

                                         [http://www.flickr.com/photos/aaronescobar/4639847862/](http://www.flickr.com/photos/aaronescobar/4639847862/)
                    
                    The Model:
                    [http://www.escobarstudios.com/mudbox_model.zip](http://www.escobarstudios.com/mudbox_model.zip)
                    
                    And a step-by-step video of how I’m causing it to  happen:
                    [http://www.youtube.com/watch?v=PEQszZxweK4](http://www.youtube.com/watch?v=PEQszZxweK4)                     

                                         Is my model broken? Are the UVs broken? Or is this  a Mudbox bug?
#2

Definitely looks like UV problems, as is the case 9 out of 10 times. Mud has very strict protocols when it comes to acceptable UV’s.

#3

http://forums.cgsociety.org/showthread.php?f=221&t=885366

why didn’t you just read this thread…it’s exactly the same problem

#4

If it’s a UV problem, how come if I create a planar mapping on the defective UVs in Maya, the problem still arises in Mudbox? Not to mention that I can fix the problem in Photoshop, so it’s Mudbox’s strict rules?

Isn’t there a simple way of fixing the UVs in Mudbox then?

#5

as i said before… mudbox is smoothing the vertex position but not the uvs by default…
you could turn on uv smoothing in the mudbox subD prefs…
or create a proper basemesh… with equilateral quads and clean uvs…
or if you only painting a lowpolymesh turn off smooth vertex position in the subD prefs and subdivide your mesh before painting…

to fix your problem above ive done a automatic mapping in maya and its working now perfect in mud…

#6

After some more tests with other models, I realised that there seems to be an association between this bug and models of low poly-count. Another cause for this bug was that with automatic mappings from Maya the individual UV shells were too close to each other and were causing Mudbox’s paint bleeding effect to overlap each shell. Bellow is an extracted text from Mudbox’s documentation:

"The UVs should be laid out in the 3D modeling or UV editing application so that a 4-6 pixel wide empty region exists along the outside perimeter of each UV shell to account for the necessary edge bleed that automatically occurs when painting.

If the UVs are spaced too close to each other, or are positioned too close to the edge of image borders (UV tile edge) seams and paint artifacts can appear on the model when it is painted."

But now I have another question, how do I automatically space each of the UV shells? Is there a way in Maya?

#7

that is no bug… its caused by smoothing the vertexposition and not the uvs…
with production ready uvs you wont run into such problems…

the automatic mapping funktion in maya has settings for uv spacing…
also the layout tool…

#8

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