Marco, you rock!!!
Spended half a day on that seamissue in Maya2008 ´til I found this thread.
Now it´s working!
Thomas
sorry!I have used your mel to do seamless displacement，but the Problem not fix
addAttr -ln “miExportCCMesh” -at bool mentalraySubdivApprox1;
I also get the error: found no valid items to add the attribute to.
the name ‘iExportCCMesh’ of new attribute clashes with an existing attribute of node SubdivApprox1
like ZC member ｋｕｒｓａｄｋ say.
I deleted old 'mentalraySubdivApprox1; 'and redo mentalraysubdivision. retry the MEL, plaster in command line and enter, the mel is disappear and not reported error.
redo render ,the seams is still here!
HELP me Please!
You’re subdivision approximation node might not be the default name which the script is refferring to. Did you make sure its the name name and everything? Default is mentalraySubdivApprox1 but urs might be mentalraySubdivApproxX, X being w/e instance it is.
Quick way to check is to cntrl+a ur mesh and see what the subapprox tab says, or check in the hypershade graph to see what the name is.
Hope that helps 
my node was named ‘mentalraySubdivApprox1’ ,as my attached file. it is appearing upstairs. i think it because Vflip Hflip,and overlapping uv.
e.g. we are always texturing for the symmetry things UV Flip and overlapping .
but bump texture be rendered appearing a part is concave and other part is raised, .
(sorry!my english is very poor!please use Chinese grammar to understand!:lol: ''Contain Errors" Is fashionable internet.)
Uhm…hmm…
Scott!!! 
have some trouble 。headache！
addAttr -ln “miExportCCMesh” -at bool $selected[$a];
intel core 1.7G cpu
ATI x2300 display card.
1024MB RAM
MAYA208 MR
Attachments
scene.zip (101 KB)
Hi,
Maya 2008 SP1 is out which should fix the UV seams issue. So the ccmesh conversion script shouldn´t be necessary any more:
http://usa.autodesk.com/adsk/servlet/ps/dl/item?siteID=123112&id=10535405&linkID=9242259
I haven´t had the chance/time to check this out but in their release notes Autodesk say that the seams issue should have gone now.
Let´s see…
Marco
Thanks for pointing out the Maya update marcotronic. I also hadn’t taken the time to install the update when you made your post. I now have installed the update for maya and mental ray. As the documentation says, the ccmesh problem is fixed. I did several renderings with no vizable seams!
Now we all have to go back and recheck the ccmesh boxes 
in our previous files.
On a side not since there are probably other people out there pushing the memory limits of rendering in mental ray… While some things have made a difference like implementing the windows xp 3gb fix have made a difference Maya 2008 has an option under window>settings/preferences>rendering there is a check box for “Use optimized textures (auto-conversion)” which converts all of your textures to OpenEXR for rendering. Don’t worry it doesn’t replace your originals. This has been alowing me to render with even more frosting!
Cheers,
Sky
Ohh thats a good one to know about Sky. I saw that checkbox and made a mental note to try it out which I never went back to do. Thanks for the post about the SP Marco! Hopefully the CCMesh will be as much of a speed boost as the documentation seems to imply it is.
Scott
maya 2008 sp1 inclued maya20008 EXtension2 ,or maya20008 EXtension2 inclued maya 2008 sp1? because it has been published at the same time !
and only enable to install one. can you show me a link form autodesk.
Hi,
I´ve read somewhere that Extension 2 already contains SP1. (I´m not a subscription customer - so I have no access to Extension 1 and 2 - only SP1) For SP1 just follow the link I´ve posted above. But if you are an Autodesk subscription member you should also have access to the extensions - I think you have a special password protected area for that on the Autodesk site.
Marco
Hi guys, I thought the stuff on this thread would answer my prayers, unfortunately there has been limited success. The bloating I was experiencing in Mental Ray has gone (after reverting to Maya-style alpha detection), but the resulting render now looks like my earlier Gelato CatmullClark result, seams and all. I have tried running Scott Spencer’s script, and assumed (wrongly) that it had worked. When I run it now a message says “//Error: Found no items to add the attribute to” - I’m assuming this is because I have run the script once already?
One thing that I am finding totally baffling is that objects created from scratch from Zbrush primitives/zspheres with no adjustment to topology are working perfectly fine with NO SEAMS whatsoever. The problem only occurs once I retopo an object in ZBrush, unwrap the UV’s externally, and then import back for dsplacement generation. I find this bizarre.
Any help would be brilliant, I am really desperate now, my final assignment must be handed in soon and my entire degree rests upon it!
Attachments
hey there petekasim, if you want send me the file(Ztool) and ill take a look at it for you…
Thanks for suggestion Atwooki, but it hasn’t worked. The seams are still appearing… This is getting depressing, as I have spent ages sculpting some highly detailed characters and can’t bear the idea of having to simplify them.
PixolClay, thanks so much for offering to take a look. I have emailed a ztool to your main email address as found on the pixolclay.com website
I tried increasing the density of the base OBJ files which I export, and it has reduced the size of the seams a bit, however I’m afraid the models will be far too dense to animate.
—(((Another note, the mental ray approximation node alone is not enough to subdivide the models accurately. Unless I smooth the mesh once, it always explodes slightly at render time. Has anyone else ever experienced this???)))—
Thanks again to anyone who may be able to help
Attachments
ZBrush generates displacement maps a little differently for ZBrush native primitives, at least I know it deals with scale differently. It is interesting you dont have the problem with something that is native ZBrush… When you export to UV then reimport to ZBrush sees it as an obj file from an external application.
Thanks for the input Scott. I would be keen to hear if you can think of any potential fixes further to the ones you have already described. Unless a solution is found very soon I’m going to have to resign myself to using normal maps only.
Considering that I’m making an animated piece, maybe all the movement will be distracting enough that the audience won’t be able to tell the difference?
Not that this is any consolation but from what your describing things are not right with your model. I have had situations where the lowres was so low I had to set the approximation WAY high to get detail but exploding meshes arent normal. I am interested in what Pixoclay has to say upon seeing the mesh/ztool.
Forgove me if you mentione this already but you are using Maya 2008 with no service pack, correct? Have you tried in other renderers?
Did you use MD3 to make your displacement map in ZBrush?
Scott
Scott, I’ve been away from the computer for a couple of days (had to clear my head), but Pixolclay just got back to me regarding the ZTool I sent him. Apparently, my UV’s were the problem!
Here’s what he had to say:
“The issue was in with your UV’s. The UV’s were
divided into different shells. Although they looked correct and merged,
they weren’t. I simply redid them in Headus and applied that to the
ZTool.”
I don’t know what has caused the UVs to “divide”, I made them by
copying the original OBJ, physically unwrapping the faces in Maya and
creating a planar UV layout, then copying the UV attributes back to my
original model. Strange.
Anyway, many thanks for the input Scott, I’m finally a step closer to establishing a decent workflow!
Hi folks,
so now I´ve had some time to check this SP1 bugfix for the ccmesh displacement stuff myself and I´m really very disappointed. Although Autodesk is mentioning in their release notes that this UV-seam problem should have gone now with SP1, it still exists !!!
I´ve made a test. With the standard behaviour (without applying Scott´s or my MEL script) there are still seams visible at the UV borders of my model. After applying that piece of MEL script they are gone. So the problem is still NOT fixed by Autodesk! 
:td:
Marco