Mudbox Painting Problem >:(

[Anonymous]

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 (AND a FBX file of my model), so you can see for yourself:

http://www.flickr.com/photos/aaronescobar/4639847862/

The Model:
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


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

mudbox_model.zip

[Christoph_Schaedl]

may i see the uvs and the lowres mesh...

think your lowress is to low and the uvs are bad...
this happens cause mudbox is smoothing the vertex position but not the uvs...

[Anonymous]

Could you simply download the model above and see what's wrong? Everyone says the UVs are bad but I spent hours doing the planar mappings in Maya. How could they be wrong?

thanks

[Christoph_Schaedl]

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..

[Anonymous]

For the record, automatic mappings did not work for me. Worked for major areas but I still get stretching at small corners :(

[rvignone]

I believe your UV's need better spacing. As of now when you paint on a UV seam, Mudbox will blur the edge of your paint stroke and if your UV's are to close, that edge blur will overlap a close UV shell. You can set the edge bleed in mudbox to 0 in the Prefs>Paint tab, but it is better to have your UV's laid out properly.

[Christoph_Schaedl]

automatic mapping on the lowress or the mesh you uploaded above..?

[Anonymous]

The mesh I uploaded but with updated automatic mappings.

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?

[Christoph_Schaedl]

there is a layout feature with spacing in maya...
and you could also adjust the spacing value in the automatic mapping settings...

[Anonymous]

Hi everyone
sorry for tha bad english
i have made various models , spaced the uv's with care automatically and manualy
setting up at best the brushes overlapping and all but the problem stand still sometimes.
WHY???
See the file to judge the spacing and the overlap..

<a href="http://s1080.photobucket.com/albums/j338/mastroprimo/?action=view&current=mudboxtexturespaintingprob... target="_blank"><img src="http://i1080.photobucket.com/albums/j338/mastroprimo/mudboxtexturespaintingprob.jpg" border="0" alt="Photobucket"></a>

[Anonymous]

Hi everyone
sorry for the bad english
i have made various models , spaced the uv's with care automatically and manualy
setting up at best the brushes overlapping and all but the problem stand still sometimes.
WHY???
See the file to judge the spacing and the overlap..


<a href="http://s1080.photobucket.com/albums/j338/mastroprimo/?action=view&current=mudboxtexturespaintingprob... target="_blank"><img src="http://i1080.photobucket.com/albums/j338/mastroprimo/mudboxtexturespaintingprob.jpg" border="0" alt="Photobucket"></a>

[Christoph_Schaedl]

that looks like projection errors to me...
if you are projecting to a poly facing away from the cam you will get stretched textures...

may i see more screens..?

[Anonymous]

Yes i understand but if you have time look this

<a href="http://s1080.photobucket.com/albums/j338/mastroprimo/?action=view&current=Paintproblems.jpg" target="_blank"><img src="http://i1080.photobucket.com/albums/j338/mastroprimo/Paintproblems.jpg" border="0" alt="Photobucket"></a>

<a href="http://s1080.photobucket.com/albums/j338/mastroprimo/?action=view&current=PaintproblemsUVS.jpg" target="_blank"><img src="http://i1080.photobucket.com/albums/j338/mastroprimo/PaintproblemsUVS.jpg" border="0" alt="Photobucket"></a>

[Anonymous]

i have add some screenshots .
Maybe the areas with problems are to rectangular shaped more squared poligons less problems...
<a href="http://s1080.photobucket.com/albums/j338/mastroprimo/?action=view&current=Paintproblems2.jpg" target="_blank"><img src="http://i1080.photobucket.com/albums/j338/mastroprimo/Paintproblems2.jpg" border="0" alt="Photobucket"></a>

<a href="http://s1080.photobucket.com/albums/j338/mastroprimo/?action=view&current=PaintproblemsUVS2.jpg" target="_blank"><img src="http://i1080.photobucket.com/albums/j338/mastroprimo/PaintproblemsUVS2.jpg" border="0" alt="Photobucket"></a>

<a href="http://s1080.photobucket.com/albums/j338/mastroprimo/?action=view&current=PaintproblemsUVS3.jpg" target="_blank"><img src="http://i1080.photobucket.com/albums/j338/mastroprimo/PaintproblemsUVS3.jpg" border="0" alt="Photobucket"></a>

[Anonymous]

i have add some screenshots .
Maybe the areas with problems are to rectangular shaped more squared poligons less problems...
<a href="http://s1080.photobucket.com/albums/j338/mastroprimo/?action=view&current=Paintproblems2.jpg" target="_blank"><img src="http://i1080.photobucket.com/albums/j338/mastroprimo/Paintproblems2.jpg" border="0" alt="Photobucket"></a>

<a href="http://s1080.photobucket.com/albums/j338/mastroprimo/?action=view&current=PaintproblemsUVS2.jpg" target="_blank"><img src="http://i1080.photobucket.com/albums/j338/mastroprimo/PaintproblemsUVS2.jpg" border="0" alt="Photobucket"></a>

<a href="http://s1080.photobucket.com/albums/j338/mastroprimo/?action=view&current=PaintproblemsUVS3.jpg" target="_blank"><img src="http://i1080.photobucket.com/albums/j338/mastroprimo/PaintproblemsUVS3.jpg" border="0" alt="Photobucket"></a>

[Anonymous]

IMPORTANT
look this simple 'discover'

low poly mesh good spacing and no very thin rectangular UVS poly area work well almost perfect

<a href="http://s1080.photobucket.com/albums/j338/mastroprimo/?action=view&current=paintproblemsnew.jpg" target="_blank"><img src="http://i1080.photobucket.com/albums/j338/mastroprimo/paintproblemsnew.jpg" border="0" alt="Photobucket"></a>

<a href="http://s1080.photobucket.com/albums/j338/mastroprimo/?action=view&current=paintproblemsnew2.jpg" target="_blank"><img src="http://i1080.photobucket.com/albums/j338/mastroprimo/paintproblemsnew2.jpg" border="0" alt="Photobucket"></a>

if i subdivide the model for sculpt , with subdivide UV first checked then unchecked the result is the same ,this

<a href="http://s1080.photobucket.com/albums/j338/mastroprimo/?action=view&current=paintproblemsnew3.jpg" target="_blank"><img src="http://i1080.photobucket.com/albums/j338/mastroprimo/paintproblemsnew3.jpg" border="0" alt="Photobucket"></a>

the texture is streched and if i paint the errors come out.
????????
any ideas?
i fail some of simple because i do basic things wrongs?
Tank you.

[Christoph_Schaedl]

if you like to use smooth uvs...
you have to do this on a clean unsubdivided mesh...

may i see the uvs and the mesh in this area on level0 with wireframe turned on..?

[Anonymous]

Hi all,

i also have seams problems when painting on my model.
Here is the way i proceed to import my model in mudbox : i created the low poly model in 3ds max, i unwrapped the uv, and then added a turbosmooth modifier (2 iterations) in order to subdivide it. Then i exported the .obj file. (10 000 poly)
Should i instead export the lowpoly mesh and subdivide it in Mudbox for better results in term of seams ?