On my side i’ve set the variable on Windows 7, and was amazed that it actually only worked with Mudbox 2012 and NOT Mudbox 2012 SAP1.
Too bad to loose the crease datas that are kept on SAP1 /(
I’m working with Arnold as renderer.
I could find a workflow consisting on baking maps on a model that was subdivided in Maya, to have smoothed UVs that will match those generated by Arnold while rendering the low poly object.
Unfortunately this worklfow doesn’t work for vector displacement extractions.........
Arnold takes only ONE UV set in account per object.
The environment variable works well.
I had SAP1 in try version. Once correctly licensed, no problem.
About the previous workflow i’ve found out that UVs corners with valence 2 could lead to distortions if using a 100% UV smooth (like keep ‘borders none’ with Maya mesh smoothing or ‘subdiv_uv_smoothing smooth’ in Arnold.
Actually the Mudbox2009 UV smoothing performs a ‘Pin_Corners’ UV smooth, where UVs with valence 2 (connected to 2 edges) are “pined”, and all other smoothed.
So for now i’m using ‘pin_corners’ UV smooth with Arnold, Mudbox2009 UV smoothing for sculpting/painting.
For the baking, i export a level 2, re import it, subdivide it to match the sculpt resolution, then extract a displace using raycast with closest to low res, and Vector Displacement extraction works also that way.
With this method i can work with crease edges on the original low poly model, and get it back when rendering.
For now it’s static picture. The next step is to find out an efficient workflow to get the subdivided output matching the original skinned low poly in order to animate.
Where is the Arnold flag you are setting for the pin corners feature ? I don’t have it exposed here as we have a customised version of it. Are you using Arnold - for Maya or softimage? I’d love to test that out.
For seamless baking we’re using Linear borders everywhere (Mudbox’s default Smooth UVs setting) with smooth internal, as Arnold on our end is doing exactly that. Its not an ideal format, as there’s distortion where the linear border meets the smooth internal UVs. Maya has this setting too
I’ve not trusted the pin corners feature as some apps do things differently (after all its sometimes ‘fudged’ as to how to smooth a UV boundary exactly how its smoothing in 3D)
I can rely on Mudbox then, to bake out seamless maps, quite often I don’t turn on the smooth UVs when baking, and pre-subdivide my base model in Maya before brining to Mudbox
We are using StoA as pipeline renderer, and i’m testing MtoA as well.
With StoA you have to add an ‘Arnold User Option’ node, where you can specify the uv smoothing mode (’subdiv_uv_smothing pin_corners’, or whatever you prefere).
In MtoA, you have a hand on it in the Attribute Editor.
If you use a homemade Arnold plugin (like i used to do before), you can edit your ass file. Search for ‘subdiv_uv_smoothing “smooth”’ in it ;).
Now with the Mudbox 2012 default UV smoothing, i’ve noticed that it actually ain’t a true Border Pin, like Arnold would do… Some UV are “pulled in”. So your shell borders are not truly linear................
Since i go the “pin_corners” way, i get seamless results.
The way you unfold your UVs seems to be important as well. I’ve read somewhere that you have to avoid splitting shells on edge loops that contains valence 5 or higher UVs. It works !
Until now i’m happy with this method. I however can’t assure you that it will work for all cases....
Another thing : I try to paint on a level that will match the subdiv iterations at rendering…
Exporting a mesh from maya with the uv smooth set there helps.
But for me exporting a higher level (1 or 2 depending on original topology) from Mudbox (with the 2009 uv smooth mode set) is a better way.
If you subdivide it in Mudbox to match the number of faces of your sculpt model, you’ll get good extraction results for displacement and Vector displacement (keeping your crease data for example).
The problem is that you have to apply your extracted maps to the mesh you’ve exported from Mudbox, in order to obtain 1-1 result.
I need to test if a more detailed base mesh allows to avoid the mesh export from Mudbox.
Then again, the pin_corners mode in Arnold comes like a savior ;)
Mudbox 2012.sp3 onwards fixed the issue with corners being pulled in when smoothing UVs, I reported it in a thread earlier in the year and it was aknowledged as a bug, so you cn get truly locked linear borders from Mudbox now,even on extraordinary vertices with UV borders.
Many thanks for the Arnold tip, I don’t use the MtoA plugin, so will set it in Arnold and give it a go. We have a Maya plugin in house that does pin corners with match borders so if thats seamless with Arnold it’d help a great deal .
Glad i could help ;)
Please let me know about your tests results.
I’m a bit noob on that, but does the SAP1 include bugfixes made on sp3 ?