Problem with OBJ Import

[Anonymous]

I've modeled a hair style in Maya and exported it as an OBJ file to be used in UVLayout.  I created my UV Map saved it as an OBJ file and reimported it into Maya and I received a message stating the following:

"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."

 

Also when I look at my outliner it shows the following:

I'm not sure why it is doing this.  I've exported OBJ files before and worked with them in UVLayout without an issue.

[cornelh · Accepted solution]

@Anonymous

The OBJ importer in Maya will usually join all objects in your OBJ as one (almost as if you had done a "combine") The way to separate these is to do a Mesh > Separate operation, and all your objects will be by themselves.  This will rename them what ever the main Poly object name and number them from 1 to what ever the number or parts you have.  This has been an issue in Maya since I can remember, the only way I have seen Maya import OBJ's and maintain groups and objects separately is by using a 3rd partly software to re-save the OBJ files, this was figured out by another cumunity member who needed all his pivot points to remain as they did, which get destroyed if you do the "separate" on them.  http://www.atangeo.com/products (it must add some flag missing in the Maya OBJ importer)  I don't remember which of the products, yet he said he only opened and re-saved the obj's again, and the groups came in separated with proper pivots.

There is a current bug logged for this issue: MAYA-71386.  I have also let the Dev. team know that when using the above 3rd party app we are able to import correctly.  So the Maya importer/exporter works yet it must need certain flags to do so correctly.  for now, "separate" if you are not worried about the pivots.. or use the above app.  I wish you the best of luck.  

[Anonymous]

okay, thank you!  I'll try that.  Also I noticed when I export out of Maya with no groups as an OBJ I'm fine, it's when I have 1 more or more groups it seems to affect all the polys.

[Anonymous]

Maya's OBJ importer has a bug where it doesn't recognize grouped geo and would therefore fail to import the geo as grouped and as multiple objects too (even when selecting the "Multiple Objects" under the OBJ importer's "File Type Specific Options" which will treat it as "Single Object"... i.e. no difference between the two options in this case; when geo-grouping is used).

The OBJ file format supports grouped geo, and Maya's OBJ exporter seems to utilize that feature and exports grouped geo fine (which can be seen when opening the OBJ in a text editor and search for the geo name that is a child of another geo, where both geo would be mentioned signifying the parent-child relationship between the two geo).

So Maya's OBJ importer cannot import what Maya's OBJ exporter can export (in regards to, and when grouped geo is used).

There is a new case as well: MAYA-87340 "Importing obj files with groups results in unusable mesh"

Cheers,

-Bassim

[Alexx31]

Hello,

I have the same problem all the time, again and again, when importing from zBrush and other softwares.

Is it really possible, that Maya has not a proper working OBJ import ??

*NIGHTMARE*

 I just hope they fix it for 2019 😞