PTex Export workflow with Mudbox to Maya

[Cruz]

Today I started messing with PTex in Mudbox 2012.

First Tests with texture layers rendered just fine in Vray.

However tests with Paint Layers and Displacement/Normal PTex files just wouldnt work.
Either one or the other.

My sculpted Mesh has 5 sub-d levels and several sculpting layers.
Since the Level 0 mesh was too far away from the final sculpt I was trying to export from Level 1 > 5.
So I extract normal and displacement maps from Level 1 > 5 as ptex files
I also extract the Paint Layers.

At first the diffuse ptx was broken showing ptex uv tiles instead of the color.
Later I compare the displaced mesh with the mudbox mesh and they are nowhere alike.


Enough blabla.

What is the correct workflow when exporting the ptex files to use them with vray and is it possible to use a higher level as base mesh than level 0?

[Zach Gray]

I've been working with the same thing. This thread may be useful.


http://www.chaosgroup.com/forums/vbu...nd-subdivision

Here is the word from Autodesk:

When distributing texels, Mudbox takes into account the size of faces *at the highest level*. So for a subd workflow be sure to subdivide the model several times (and either sculpt or apply any displacements) *before* setting up ptex.

http://www.chaosgroup.com/forums/vbulletin/showthread.php?64634-Vector-Displacement-with-Mudbox

I'd be interested to know if you get displacement/vector displacement working. I've been getting seams in vector displace extraction.

[Cruz]

Hi Zach,

yeah I've been having the same vector displacement issues.

This info about subdividing before setting up ptex is valuable information, however if this is the only way I seem to be stuck with a sculpt I made yesterday...
I can always try to transfer the layers to an other model but this gave me bad results before.

I noticed your thread after posting this one and had a brief look but it seems noone has a working solution yet.

Thinking about subdividing before sculpting (and setting up ptex). This just seems twisted to me. How would I know how coarse I want my sculpt to be before I even start sculpting??? Am I missing something? Going up to Level 8 before starting 'to make sure' sounds pretty backwards to me.

[Zach Gray]

Thinking about subdividing before sculpting (and setting up ptex). This just seems twisted to me. How would I know how coarse I want my sculpt to be before I even start sculpting??? Am I missing something? Going up to Level 8 before starting 'to make sure' sounds pretty backwards to me.

After reading the disney presentation on the subject, it's a way to remove distortion as the surface is subdivided. Mudbox isn't subdiv aware. It just increases the poly count. Both approaches distort from the limit surface.

I think the key is to setup your ptex last, after you are done subdividing.

[Cruz]

so what if i then notice I need 1 or 2 more levels to achieve the detail I need? This seems weird to me