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particle_system.co_hair does not account for vertex groups
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Description

--- Operating System, Graphics card ---
OS X 10.8


--- Blender version with error, and version that worked ---
r57881, 2.67b works correctly


--- Short description of error ---
LuxBlend exports hair by getting the strand coordinates from Blender, as particle_system.co_hair(obj, mod, pindex, step)

In 2.67b, this works as expected (exported hair matches viewport/BI/Cycles). In 2.68/svn however, the resulting hair is not affected by vertex groups.

--- Steps for others to reproduce the error (preferably based on attached .blend file) ---
This is most likely a general issue with the API. If you want to reproduce with LuxBlend:

-Download hair_length_feather.blend from this post: http://www.luxrender.net/forum/viewtopic.php?f=11&t=3058&start=230#p98282
-Export with 2.67b and LuxBlend rev da888e267ebe Hair will match viewport
-Export again with svn Blender and LuxBlend rev c27ffe75f7cb (hair export code is the same in both LuxBlend versions, the version change is for an API change in pynodes. da888e267ebe does not work with 2.68, c27ffe75f7cb does not work with 2.67b)

Event Timeline

I can't find the change in Blender, looks like this is actually in LuxBlend. If you diff geometry.py between the two version you will see some differences in the particle export, the older could would skip exporting parent particle hairs.

The parent particle hairs are are unaffected by the vertex group (there's a design issue in the particle code that prevents this, kind of a known bug), so that's what makes this confusing.

Ouch. You're right. Looks like a merge goofup on geometry.py. Sorry for the false alarm, you can close this.

Brecht Van Lommel (brecht) changed the task status from Unknown Status to Archived.Jul 1 2013, 2:57 AM