Send to Mudbox UV errors

[Sam Bowling]

Hi, I’ve been working with Mudbox again using the Send to feature and noticed the UV problems are still there. I was wondering if anyone has come up with an easy solution to the UV problems.

 

This seems to be a problem coming from Softimage models that have been mirrored when modeling (Everything was frozen before exporting, including UVs ). If I use Flatten to UV space It looks like my mesh has been triangulated and the triangulation is even across the entire mesh, instead of being mirrored as I would expect.  I was able to fix the problem by sending the model back to Softimage and using cycle UVs on the half of the model that has the problem. this fixed most of the problems, but there were still a few places I had to go in and detach the uvs and rearrange them by had. Several looked like they had been flipped.  Once the UVs were fixed they remained fixed if I sent them to a new scene in Mudbox, even after saving and reloading the scene in Softimage. The triangulation of the polygons on the fixed model is now mirrored as I would expect.

[jo benayoun]

Hi Sam,

I often use Mudbox coupled or not to Softimage and never got that problem. I tried to reproduce it from indications you provide, but unsuccessfully. I'm quite interested by preventing myself for the future about something like this. Are you able to provide a sample scene that reproduce the errors, or exact steps ? Which version of Mudbox/Softimage do you use ?

thanks

jo

[Eric Turman]

I have seen this behavior with the goZ as well or bringing things back from UV layout... UVs get jacked when going through the OBJ. they *look* fine but especially when copy/pating between a pre-export and post-export the problem becomes evident. Unfortunately GATOR is iffy with UVs :-/

--




-=T=-

[Sam Bowling]

Thinking more about the problem, I have only seen it on this one object, which was originally created in LightWave and then imported into Softimage. So, the problem may have originated during the import from lightwave or somewhere else. This is the same object that had the “Interior vertex Valence” problem.

 

Anyway, the best way to check if the problem is there is to paint on the object. I only painted 3 lines on the object below and this is the result I got. This will not show up as a problem if you are sculpting, at least on my object. It is odd that this only shows up on the half of the mesh that I mirrored.

 

[Tim Leydecker]

I found a flaw using XSI2012 and Mudbox2012 in the way
the UVs created using Unfold ended up in Mudbox.

The UVs would come in unmerged, e.g. not as connected shells but
each face it´s own seperate "island", and would even have the occasional
random face flipped, even thought they appeared to be layed out correctly
inside the XSI Texture Editor and rendered correctly using a checkerboard tx.

The workaround was to not use *.fbx as the transfer container but
resort to *.obj which resulted in the UVset being correctly transfered
over, including the shells.

I therefor suspect the *.fbx container as part of the "Send to" command as
the possible source of your problem.

Cheers,

tim

P.S: Just welding UVs based on threshold in, let´s say Maya, doesn´t help,
due to the randomly flipped faces.

On 16.11.2011 05:42, Sam Bowling wrote:
> Thinking more about the problem, I have only seen it on this one object, which was originally created in LightWave and then imported into Softimage. So, the problem may have
> originated during the import from lightwave or somewhere else. This is the same object that had the “Interior vertex Valence” problem.
> Anyway, the best way to check if the problem is there is to paint on the object. I only painted 3 lines on the object below and this is the result I got. This will not show up as a
> problem if you are sculpting, at least on my object. It is odd that this only shows up on the half of the mesh that I mirrored.

> MudUVerrSM
> *From:* jo benayoun <mailto:joben...@gmail.com>
> *Sent:* Tuesday, November 15, 2011 2:50 PM
> *To:* soft...@listproc.autodesk.com <mailto:soft...@listproc.autodesk.com>
> *Subject:* Re: Send to Mudbox UV errors

[Steffen Dünner]

I noticed another flaw in the Softimage -> FBX -> Mudbox workflow.

Most of the time I use smoothed UVs. This works fine when I import OBJs into Mudbox, you can see the smoothing in the Mudbox UV view and the exported maps match Softimage's own UV smoothing perfectly (as well as mental ray's and Arnold's).

When I import FBX or use the "Send to Mudbox" button (which uses FBX internally as well), UVs don't get smoothed, no matter what I set the Mudbox subdivision options to. They stay linear.

And on top of this, depending on the topology of the mesh there often is no edge bleeding on these FBXs while the same topology imported as OBJ is all fine.

Cheers

Steffen

2011/11/16 Tim Leydecker <baue...@gmx.de>

I found a flaw using XSI2012 and Mudbox2012 in the way
the UVs created using Unfold ended up in Mudbox.

The UVs would come in unmerged, e.g. not as connected shells but
each face it´s own seperate "island", and would even have the occasional
random face flipped, even thought they appeared to be layed out correctly
inside the XSI Texture Editor and rendered correctly using a checkerboard tx.

The workaround was to not use *.fbx as the transfer container but
resort to *.obj which resulted in the UVset being correctly transfered
over, including the shells.

I therefor suspect the *.fbx container as part of the "Send to" command as
the possible source of your problem.

Cheers,

tim

P.S: Just welding UVs based on threshold in, let´s say Maya, doesn´t help,
due to the randomly flipped faces.

On 16.11.2011 05:42, Sam Bowling wrote:

Thinking more about the problem, I have only seen it on this one object, which was originally created in LightWave and then imported into Softimage. So, the problem may have
originated during the import from lightwave or somewhere else. This is the same object that had the “Interior vertex Valence” problem.
Anyway, the best way to check if the problem is there is to paint on the object. I only painted 3 lines on the object below and this is the result I got. This will not show up as a
problem if you are sculpting, at least on my object. It is odd that this only shows up on the half of the mesh that I mirrored.

MudUVerrSM
*From:* jo benayoun <mailto:joben...@gmail.com>
*Sent:* Tuesday, November 15, 2011 2:50 PM

*To:* soft...@listproc.autodesk.com <mailto:softimage@listproc.autodesk.com>

*Subject:* Re: Send to Mudbox UV errors

Hi Sam,
I often use Mudbox coupled or not to Softimage and never got that problem. I tried to reproduce it from indications you provide, but unsuccessfully. I'm quite interested by
preventing myself for the future about something like this. Are you able to provide a sample scene that reproduce the errors, or exact steps ? Which version of Mudbox/Softimage do
you use ?
thanks
jo

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Fingerprint: 394B 3DA9 9A9A 96C6  3A5A 0595 EF92 EE1F

[Tim Leydecker]

Hey Steffen,

might be the same root problem, the individual faces
seem to be exported as isolate faces, e.g. several
UVs per vertex even thought one would desire to have
only 1 UV where vertices align on top of each other in
the UV space to form a shell.

One can´t smooth, because it´s no shell but separate faces...

Cheers,

tim

P.S: On an unrelated note, I mistakenly switched off "smooth UVs"
once inside Mudbox. Loads of grief and learning it the hard way...

On 16.11.2011 10:42, Steffen Dünner wrote:
> I noticed another flaw in the Softimage -> FBX -> Mudbox workflow.
> Most of the time I use smoothed UVs. This works fine when I import OBJs into Mudbox, you can see the smoothing in the Mudbox UV view and the exported maps match Softimage's own UV
> smoothing perfectly (as well as mental ray's and Arnold's).
> When I import FBX or use the "Send to Mudbox" button (which uses FBX internally as well), UVs don't get smoothed, no matter what I set the Mudbox subdivision options to. They stay
> linear.
> And on top of this, depending on the topology of the mesh there often is no edge bleeding on these FBXs while the same topology imported as OBJ is all fine.
>
> Cheers
> Steffen
>
>

> 2011/11/16 Tim Leydecker <baue...@gmx.de <mailto:baue...@gmx.de>>

>
> I found a flaw using XSI2012 and Mudbox2012 in the way
> the UVs created using Unfold ended up in Mudbox.
>
> The UVs would come in unmerged, e.g. not as connected shells but
> each face it´s own seperate "island", and would even have the occasional
> random face flipped, even thought they appeared to be layed out correctly
> inside the XSI Texture Editor and rendered correctly using a checkerboard tx.
>
> The workaround was to not use *.fbx as the transfer container but
> resort to *.obj which resulted in the UVset being correctly transfered
> over, including the shells.
>
> I therefor suspect the *.fbx container as part of the "Send to" command as
> the possible source of your problem.
>
> Cheers,
>
> tim
>
> P.S: Just welding UVs based on threshold in, let´s say Maya, doesn´t help,
> due to the randomly flipped faces.
>
>
> On 16.11.2011 05:42, Sam Bowling wrote:
>
> Thinking more about the problem, I have only seen it on this one object, which was originally created in LightWave and then imported into Softimage. So, the problem may have
> originated during the import from lightwave or somewhere else. This is the same object that had the “Interior vertex Valence” problem.
> Anyway, the best way to check if the problem is there is to paint on the object. I only painted 3 lines on the object below and this is the result I got. This will not show
> up as a
> problem if you are sculpting, at least on my object. It is odd that this only shows up on the half of the mesh that I mirrored.
> MudUVerrSM

> *From:* jo benayoun <mailto:joben...@gmail.com <mailto:joben...@gmail.com>>

> *Sent:* Tuesday, November 15, 2011 2:50 PM

> *To:* soft...@listproc.autodesk. com <mailto:soft...@listproc.autodesk.com> <mailto:softimage@listproc. autodesk.com <mailto:soft...@listproc.autodesk.com>>

[Steffen Dünner]

Yes, this sound plausible. Do you know if this only happens to Softimage exported FBX files or if it is a problem with all FBX?

Cheers

Steffen

2011/11/16 Tim Leydecker <baue...@gmx.de>

might be the same root problem, the individual faces

seem to be exported as isolate faces, e.g. several
UVs per vertex even thought one would desire to have
only 1 UV where vertices align on top of each other in
the UV space to form a shell.

[Tim Leydecker]

I don´t know if this also affects *.fbx in Maya 2012,
I haven´t used Maya 2012 in production yet.

The pipeline required Maya 2011 assets, which comes
with an older version of the *.fbx implementation,
compared to Softimage2012 and Mudbox2012.

I tried exporting an *.fbx from Softimage2012 into Maya 2011,
then re-exporting that *.fbx to Mudbox2012 but couldn´t automagically
get rid of flipped faces introduced through export from Softimage2012
to *.fbx, once they where incorrectly flipped, they kept being flipped,
althought that merging UVs by distance threshold in Maya would work,
those shells had random faces flipped and proved too time-consuming
(while possible) to manually flip indivually, then merge back into the shell.

It was faster to resort to *.obj for transfer to Mudbox, export to *.obj,
import and then conform to asset requirements inside Maya, like re-transfering
a second UV map, checking for the correct scale, freezing history, shaders,.etc

*.obj export only supports one shell, Softimage will export the first it finds,
it´s therefor helpful to just nuke all the ones but the one that should come over :-)

Cheers,

tim

On 16.11.2011 10:57, Steffen Dünner wrote:
> Yes, this sound plausible. Do you know if this only happens to Softimage exported FBX files or if it is a problem with all FBX?
>
> Cheers
> Steffen
>
>

> 2011/11/16 Tim Leydecker <baue...@gmx.de <mailto:baue...@gmx.de>>