blender obj files and matrixoutput

Jun 3, 2007 at 3:50am

blender obj files and matrixoutput

Hi all,

It appears that blender-generated wavefront files wreak havoc with
jit.gl.model when matrixoutput is set to 1. The object outputs nothing
whatsoever and hence there is no visual output nor an ability to use
blender-generated models for morphing purposes, yet if matrixoutput is set
to 0, the object shows-up just fine in the jit.window.

A quick inspection of the obj files and comparing them with mushrooms.obj
file suggests that in the case of blender-generated file, there is a small
header which says “blender v244″ etc. If jit.gl.model matrix output is
trying to parse out vertices (I presume those are points with v in front of
them), perhaps this first v in v244 is messing everything up and making
output unreadable.

Any ideas as to how this can be circumvented/fixed? Is there a better export
path from blender?

This is using latest blender (2.44) with Jitter 1.63.

Many thanks!

Ivica Ico Bukvic, D.M.A.
Composition, Music Technology, CCTAD, CHCI
Virginia Tech
Dept. of Music – 0240
Blacksburg, VA 24061
(540) 231-1137
(540) 231-5034 (fax)
ico@vt.edu
http://www.music.vt.edu/people/faculty/bukvic/

http://ico.bukvic.net

#32245
Jun 3, 2007 at 4:30am

> A quick inspection of the obj files and comparing them with mushrooms.obj
> file suggests that in the case of blender-generated file, there is a small
> header which says “blender v244″ etc. If jit.gl.model matrix output is
> trying to parse out vertices (I presume those are points with v in front
> of
> them), perhaps this first v in v244 is messing everything up and making
> output unreadable.

More inspection suggests this is not the case (originally for some
inexplicable reason my editor opened obj files as binary/hex files–let’s
just say their plain text inspection showed that the header in question was
commented out). Could it be the fact that my test object (cube for instance
that is in the default scene when Blender is started) did not have any
texturing info?

Ico

#105698
Jun 3, 2007 at 5:31am

Never mind. Figured it out.

For those seeking answer to similar blender+obj+jitter issues, here’s a
work-around:

Symptom(s): blender-exported wavefront obj files are not compatible with
jit.gl.model’s matrixoutput but do display fine when matrixoutput is
disabled

Cause: apparently blender’s export plugin for the wavefront format is not
entirely format-compliant (so far both wings3d and jitter have complained
about it). 3ds export plugin seems to have some problems as well.

Resolution:

1) export blender object in nendo (.ndo) format
2) import it in wings3d
3) export from wings3d in wavefront (.obj) format

What is puzzling however, is since both wings3d and blender are open source,
why hasn’t blender project adopted apparently correct implementation of
wavefront .obj format found in wings3d?

Best wishes,

Ico

#105699

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