URGENT: shapekey / blendshapes between Maya and Blender

I’m at production stage of my studies in 3D animation on a course where we mainly use Maya 2008. I’ve been using Blender for making animation characters etc, although my tutors are skeptical about Blender’s abilities… they are allowing me to use it but I can’t ask them for help on Blender related issues.

I was inspired by http://www.blendernation.com/2007/09/07/blender-animated-television-series/ which made it sound like working between Maya and Blender would be fairly painless. I love the sculpting tools in Blender but as far as using it to alter to make a morphable blendshape (shapekey) for use in Maya… that’s where I have hit a snag.

Example:
If I make a mesh in Maya (or in Blender), delete history etc and then export a clone of this (OBJ format) into Blender for tweaking and then back again into Maya, when I use the Maya “create blend shape” function between the original and the new mesh, the resulting morph always gets the verticies randomly messed up. One or two of the vertices are in the correct position (e.g. don’t move during the change) but most vertices play musical chairs and make something of a jagged porcupine of my final character. :ba:

I have played with some options… “rotate 90” is not the issue because if it’s not selected, the mesh actually does face the wrong way. I have also used the “Morph Target” option (both on import and export) to preserve vertex order but this has not changed anything. :eek:

Like I said, I am now in final production stage of graduation (eleven weeks left)… need help on this one ASAP please.

Have you tried any other formats?
The fbx exporter maybe works.
Blender got pretty many export options, so I think there should be one that should do the magic for you.

I would be surprised if the fbx doesn’t work. Autodesk have some tools on their website too. Look in the downloads section for the fbx converter.

Regards
/t3d

Thanks.

I knew FBX export was there (used it before) but overlooked it this time because I immediately went to FBX import and that wasn’t in the Blender options. Now you have pointed it out to me afresh, yes it can solve the problem with a little playing around. :smiley: :smiley: :smiley:

Solution:

Generally use OBJ to both export / import files to and from Maya / Blender.
If mesh is originally made in Maya, there seems to be some inconsistency in the fileformats which makes Blender reorder the vertices on the first export as OBJ. You can get around this by exporting from Blender to Maya as FBX to avoid it rewriting vertex order on OBJ (morph target option does not appear to work).

…at least I think that’s what’s happening. Here’s a summary of smaller steps of my troubleshooting this morning. I don’t right now have time to play much more…

  • I made (and saved for safe keeping) a simple character in Maya.
  • Still in Maya, I exported the character as OBJ for use in Blender (Blender has no options to import FBX, only export)
  • In Blender I imported the OBJ and altered it to make a simple shapekey / blendshape (I moves its arm into a waving position).
  • In Blender, I exported the adjusted mesh as OBJ (options: selection only, rotate 90 and morph target) and I also exported another copy as FBX (there were no export options)
  • In Maya, I imported the Blender adjusted OBJ into my scene. I linked it to the original as a new blendshape (shapekey). It looked promising until I used the sliderbar to morph from one to the other. There’s my original problem: the vertices scramble around all over the place (have been reordered).
  • In Maya still, this time I imported the adjusted FBX version of the file. It was in a “fallen over” (flat on its face) position but making the blendshape (shapekey) resulted in a sliderbar that make my character move smoothly from a standing arms out position to a lying flat on his face with arm successfully raised position.
  • I fixed the lying down position by going to my imported FBX morphshape character and performing rotX -90 and then freeze transforms. Immediately the blendshape was cured and the movement was that my character was able to move his arm while staying upright. It appears quite safe to delete history on the imported FBX version after the rotX -90.
  • I looked for export / import options to fix the lying down flat on his face issue. There is a change world order option (y/z), but this only makes the problem worse in another way. I’ll live with rotating newly imported shapes for now, as long as this doesn’t break on my bigger mission critical projects. (have not yet tested results on weight painting for rigged characters or partial blendshapes [e.g: smaller mesh for just the head]) Where is this scrambling happening?
    Here’s the thing… the scrambling ONLY seems to happen to meshes that were first made in Maya and then imported as OBJ to Blender and then re-exported as OBJ from Blender to Maya. If the Mesh was first made in Blender, there does not seem to be the vertex scramble problem, only with Maya made mesh.
    It appears that Maya and Blender write OBJs slightly differently and that Blender doesn’t like something in the Maya OBJ causing it to rewrite the vertex order afresh on its first save. Maya on the other hand seems quite graceful about Blender OBJs, as the files don’t appear to get mutated once they have been through Blender at least once (e.g. if the mesh was created in Blender first). If this is the case, I would welcome Blender writers to revamp the OBJ import script to fix this.

Thanks for your help. Maybe the above can help someone else googling for a similar issue? I gotta bit of catching up to do now so hopefully Blender will be able to speed me up with those sculpting tools.

I’ve had the same problems making morph targets for DAZ|Studio. Except it seems to be totally random with me. I though the problem came from applying modifiers in blender and then exporting. The verts were all porcupined, as you so fittingly put it, Lancer. So usually I would just make morphs using scale or other transforms, or grabbing individual verts, then exporting just the group that I needed. But now I’m having the vert ordering problem, even though I’m following the same procedure as usual. What gives? Maybe I’ll try that fbx thing, though I don’t know if I can import that to DAZ. Is there another way to convert it?

See these posts for more details: http://blenderunderground.com/forums/viewtopic.php?t=1094
http://forum.daz3d.com/viewtopic.php?t=91514&highlight=

Hi,
Did you find any solution?

the blend-shape in Maya works for me no problem , same couple of objects , sometimes randomly shape key does not work in Blender, seems like blender changes the vertex order, very frustrating .