Send to Mudbox 2012 SAP from Maya Tip — Fix for No Hard Edges

All right, there is another quick fix for yet another problem with Autodesk Maya — today I've tried to export my model to Mudbox via "Send to Mudbox" feature and found that new Mudbox 2012 SAP feature that made it support hard edges import from Maya ( 3ds Max and Softimage too ) not working as expected. When I exported model manually with correct FBX settings and imported it in Mudbox — everything works smoothly, hard edges are there. But as soon as I've tried to use "Send to Mudbox" feature — all hard edges are lost independently from FBX preset settings or selected preset.

Fortunately I've managed to figure out what's wrong with Maya and why "Send to Mudbox" can't export hard edges properly. As you may know, this feature uses FBX format for data exchange between Maya and Mudbox, so it depends on FBX plugin settings. For some reason Maya always uses default FBX preset for "Send to Mudbox" — Autodesk Media and Entertainment, even if you have custom preset set for manual Export in FBX format. Problem lies right there — in Autodesk Media and Entertainment preset, where required for hard edges export option isn't enabled.

To export hard edges with FBX, you should have checked Smoothing Groups option in Geometry sections of the preset ( see picture below ). All we need to do is to go to C:\Program Files\Autodesk\Maya2012\bin\plug-ins\FBX\Presets\2012.1.1\export and edit Autodesk Media & Entertainment.fbxexportpreset file, changing this option to be checked ( enabled ). Open Autodesk Media & Entertainment.fbxexportpreset with any text editor, find following string:

<SmoothingGroups UIH="0" UID="0" UIG="0" UIBG="0" lbENU="Smoothing Groups" dt="Bool" v="0"/>

and change its v="0" to v="1", so it looks like this:

<SmoothingGroups UIH="0" UID="0" UIG="0" UIBG="0" lbENU="Smoothing Groups" dt="Bool" v="1"/>

I think that this approach can be applied to 3ds Max and Softimage aswell, if they use similar scheme — you just need to locate where your preset files are stored ( most likely it will be in bin/plug-ins/FBX folder ).

Update: Looks like not everything goes smoothly even with this trick — Mudbox tends to be very slow on import when Smoothing Groups option is enabled. It took about 30 seconds to import a mesh with ~120,000 triangles and more than 2 minuttes for ~250,000 triangles mesh. So, import time increased in geometrical progression — for 2 times bigger triangles count it took 4 times longer to import it. ~1 million triangles mesh will be improting around an hour, and that is unacceptable, of course.

So, right now Mudbox 2012 SAP can't operate with complex geometry and hard edges data at the same time — you need to choose, if you will be able to use "Send to Mudbox" command with hard edges info and be unable to send this way complex geometry ( using a trick available above ), or you will have fast Maya-to-Mudbox and Mudbox-to-Maya exchange, but without hard edges. Of course you can always use manual Export in Maya and send your low-poly model with hard edges on it to Mudbox. I think that I will stick with solution above for a while and see how it goes, because it's unlikely that I will need to send very complex geometry from Maya to Mudbox.