Mudbox moves UVs at texture export

[Anonymous]

Hi,

I have created a UV Atlas in Maya for four models. No UVs overlap any other:

I export these 4 models into the same Mudbox scene and with the UV map.

I set a separate material for each model to sculpt high-poly and texture.

I'd like to keep the atlas format of the textures, so I intended merging the models layers in photoshop into a single texture. (I can't find a way to extract a channel of all models in one).

However I'm finding maya or mudbox move the UVs so the shells end up one on top of the other.

This is the eyes uv diffuse texture extracted as TIF 8-bit and how it overlaps the position of the humanoid TIF diffuse texture shells.

Eyes texture:

humanoid texture:

Eyes texture on humanoid texture - layers on photoshop:

I can't re-arrange these because I'd then also need to make the UV match it precisely.

I've got two questions please:

- How can i export the textures from Maya into Mudbox so the shells don't move?

- would you recommend i use the same material for all models if I want to keep the uv map/textures as an atlas? If so, is there a way to re-assign a material to a model and re-assign the textures of the old material?

Thank you for your help,

Sergio

[Anonymous]

My apologies, I was not using Photoshop's Edit-Paste Special - Paste in Place (but just paste).

However, even with this the shells are much closer to each other in the resulting merged texture with photoshop. Quite easy to see with the eye shells (in yellow) particularly bottom left.

Here's Mayas UV map and beneath pasted in place with Photoshop diffuse textures to get the atlas:

maya UV mapphotoshop pasteInPlace separate maps

Do the shells enlarge in mudbox, ever so slight? Do you have any recommendations to keep the sizes as built in Maya?

Thank you for your help

Sergio

[Christoph_Schaedl · Accepted solution]

for me this looks like the edge bleeding mudbox is doing to prevent mipmapping issues...

[jill.ramsay · Accepted solution]

Yes, it does look like that. You can set the bleed value in Mudbox under Windows -> Preferences -> Paint -> Edge Bleed. You can also visualize it in the UV View, if you have Render Edge Bleed turned on.

[Anonymous]

Thanks a bunch for your thoughts and pointer to control the bleed !