Incorrect assignment of Smoothing Groups on export #36636

New Issue

Mariachi Maltesers · 2013-09-02T11:59:51+02:00

2013-09-02 11:59:51 +02:00

%%%Smoothing groups aren't correctly assigned and exported in the obj exporter.

As an example I tested a simple cube with all edges sharp (Blender_Mesh.jpg).

In this example smoothing groups should be assigned, so
that no face is in the same smoothing group which isn't the case (How_SG_Are_Exported_RightNow.jpg).

Also, I attach a Blender exported obj file, 3ds Max desired behaviour obj file
and an image showing how smoothing groups should be assigned.

%%%

%%%Smoothing groups aren't correctly assigned and exported in the obj exporter. As an example I tested a simple cube with all edges sharp (Blender_Mesh.jpg). In this example smoothing groups should be assigned, so that no face is in the same smoothing group which isn't the case (How_SG_Are_Exported_RightNow.jpg). Also, I attach a Blender exported obj file, 3ds Max desired behaviour obj file and an image showing how smoothing groups should be assigned. %%%

Mariachi Maltesers commented

2013-09-02 11:59:51 +02:00

Changed status to: 'Open'

Mariachi Maltesers commented

2013-09-02 12:09:18 +02:00

%%%Blender version: 2.68a %%%

Brecht Van Lommel commented

2013-09-02 14:56:59 +02:00

%%%I guess 3ds max expects smoothing groups as bits? I don't know if that's part of the OBJ standard, but at least FBX seems to expect that too:
http://docs.autodesk.com/FBX/2013/ENU/FBX-SDK-Documentation/index.html?url=cpp_ref/class_fbx_geometry_converter.html,topicNumber=cpp_ref_class_fbx_geometry_converter_html,hash=a558faac41b53bc7daafa36d71fffe27d%%%

%%%I guess 3ds max expects smoothing groups as bits? I don't know if that's part of the OBJ standard, but at least FBX seems to expect that too: http://docs.autodesk.com/FBX/2013/ENU/FBX-SDK-Documentation/index.html?url=cpp_ref/class_fbx_geometry_converter.html,topicNumber=cpp_ref_class_fbx_geometry_converter_html,hash=a558faac41b53bc7daafa36d71fffe27d%%%

Bastien Montagne commented

2013-09-02 15:47:16 +02:00

%%%Yes, indeed… working on this (as with only 32 possible value, we have to be able to reuse same bit for different non-contiguous smooth groups :/ ).%%%

Bastien Montagne commented

2013-09-02 19:16:34 +02:00

%%%Think it’s fixed in r59743, thanks for the report! :)%%%

Bastien Montagne commented

2013-09-02 19:16:34 +02:00

Changed status from 'Open' to: 'Resolved'

Bastien Montagne closed this issue

2013-09-02 19:16:34 +02:00

Bastien Montagne commented

2013-09-02 20:36:39 +02:00

%%%Actually, we do not always want to export smooth groups as bitflags, so now you have the choice (either simple incrementing values for each group, of bitflags reused for many (non-contiguous) groups...%%%

Mariachi Maltesers commented

2013-09-02 23:23:03 +02:00

%%%
I tested it with a couple of quite complex models,
works absolutely perfect!

There will be just one smoothing groups checkbox finally though, right?%%%

%%% I tested it with a couple of quite complex models, works absolutely perfect! There will be just one smoothing groups checkbox finally though, right?%%%

Campbell Barton commented

2013-09-12 04:16:38 +02:00

%%%@Mariachi Maltesers, no, because OBJ defines each number as a different smooth group, there is no mention of using then as bitflags, this is an incorrect interpretation of smooth-groups, but worth supporting since it seems some applications expect it.%%%

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Incorrect assignment of Smoothing Groups on export #36636