Maya 2015 SP6 EXT1: OBJ File Contains Faces Shared By Multiple Groups

[Anonymous]

Hi Folks,

At a loss on this one; obviously missing something simple - not sure what though.

Have a model of a house that contains *no* combined meshes.  I have grouped the various parts of the polymesh in the outliner as follows:

BUILDING01 is one of the buildings in a large scene.  What I'm doing at the moment is exporting the selection (i.e. BUILDING01) as an .OBJ - has to be this format.

As a test, I created a new scene and imported the .OBJ.  I get the following information message:

"Your OBJ file contains faces shared by multiple groups.  Maya cannot create multiple objects for this file.  A single mesh object will be created instead.  The OBJ group information will be captured in Maya sets."

Disabling Groups (and Point Groups) skips the information message but I end up with the same results ... a single polymesh in the Outliner.  I can use the Polygons > Mesh > Separate function but I lose the hierarchy and associated polymesh names. 

Is there a proper method of exporting to .OBJ while preserving the Outline hierachy?

Advance thanks,

hgagne

[Anonymous]

Have you tried ticking the option at the bottom of the panel 'Multiple Objects' and tick the 'Use legacy vertex ordering'?

[Anonymous]

Hi natcoll,

Appreciate the reply; the .OBJExport panel doesn't appear to have the "Legacy Vertex" option anymore ...

[damaggio]

Out of Maya, the best option is FBX...obj is terrible in Maya...maybe try that.

[Anonymous]

Hi damaggio,

Appreciate the reply; I have exported an .FBX version - tested in 3DS Max and a re-import in Maya.

Understanding that .OBJ is not ideal, would appreciate some confirmation that .OBJ is just *not* capable of supporting groups ... seems like .OBJ is still accepted as one of the defacto output standards that a "good" mesh/scene should support.

Cheers,

[damaggio]

From my experience when I export OBJ, even as groups it comes out as one merged mesh....stick with the FBX whenever you can, I really don't know technically why it does not work as OBJ.

[Anonymous]

Much appreciated!

I was able to export the .OBJ via 3DS Max 2015 ... at least the meshes are named according to their original "topmost" group names as opposed to PolySurface with a bunch of SETS.

Separating the meshes creates "PolySurface" entries but at least it localised - i.e. not Outliner > PolySurface > PolySurface.

Cheers,

[santd]

Hello,

Thank you for posting to the Area Forums.

From testing in Maya it doesn't seem to be quite possible with the OBJ format. I do see that Maya creates sets with different face selections depending on the group they existed in, but it is difficult to translate that into the hierarchy that actually existed. I usually stick with OBJ when only exporting the model and no other information. If I am trying to get other information such as hierarchy, animation, rig, etc. I stick to FBX.

Hope you are able to workaround this issue somehow, but I am not really finding a way with OBJ.

Cheers,

[Anonymous]

Hi santd,

Appreciate the reply.

As you can see from the original post screen capture; the model meshes have been organized into group.  I have separate groups (not displayed) for lights, cameras, etc. at the Outliner Top Level.

I exported to .OBJ by selecting the "Building" group assuming that when I choose File > Export Selection, the exporter would export the group name and meshes.  Obviously, that's not working as expected. 

As per my previous post(s) in this thread, I ended up having to use the Maya .FBX exporter, importing the .FBX into 3DS Max 2015, and then use the 3DS Max OBJ exporter.

I guess the "take away" from this reply is that ADSK should look to build a "standardized" set of individual exporters (ex: OBJ, FBX, etc.) that function across their entire product lines.  Understanding that this may be an initial coordination effort, it would certainly go a *long way* into standardizing the user experience with native exporters - i.e. the behavior would be consistent regardless of products.

JMHO.