[Robotics] COLLADA 1.5 armature support?

William Hilton wmhilton at drexel.edu
Wed Feb 6 21:48:45 CET 2013


Hi Stefan,
I had come across the OpenGRASP Robot Editor page earlier in my search, but
had been holding out because I didn't want to use an older version of
Blender. I will try installing the version from SVN.

I'm not sure that what you are describing is what I want to do. I am not
trying to export an armature from Blender to OpenRAVE. Rather, I'm trying
to import an armature from OpenRAVE to Blender. You are probably a great
person to ask about this! Is there a way to do it without exporting to
Collada 1.5 first? What I ultimately want to do is animate the Blender
model using .BVH files, bake and tweak the motions to be more "doable", and
then export the joint angles from Blender and run the motion in OpenRAVE.
Will
--
William Hilton
MET-lab PhD Student, ECE Department, Drexel University
Website: http://music.ece.drexel.edu/people/wmhilton
Email: wmhilton at drexel.edu
SMS: 513-368-5411


On Wed, Feb 6, 2013 at 6:12 AM, <ulbrich at ira.uka.de> wrote:

>
> Hello,
>
> an alternative is the RobotEditor that is part of the OpenGRASP
> project (http://opengrasp.sourcefoge.net).
> The version on this homepage is outdated and works only with blender
> up to 2.49. However, we are currently
> working on a newer version compatible with blender 2.6x and only
> Collada 1.5 import is not working yet.
> It is in the official SVN and I will update the homepage within the
> next weeks. Note that it is in kind of a beta state.
>
> svn co
> https://opengrasp.svn.sourceforge.net/svnroot/opengrasp/RobotEditor2/
> RobotEditor
>
> You cannot use the plugin to directly export your armature. You rather
> have to use the plugin to create a new one with
> annotations such as DH-parameters or acceleration/deceleration/joint
> speeds. The collada files should again work
> with the newest version of OpenRAVE.
>
> Under the hood, the regular collada export is used, and the resulting
> file is augmented by collada 1.5 tags (via python)
> without additional dependencies -- installation is hence very easy.
>
> I encourage you to try it out.
>
> Best,
> Stefan Ulbrich
>
>
>
>
>
> Zitat von Séverin Lemaignan <severin.lemaignan at laas.fr>:
>
> > After a look to the Collada spec, what Blender supports are joints for
> > animation skeletons and skin (page 110 of Collada 1.5 spec). These
> > joints do not support limits for instance (only a transformation matrix).
> >
> > What OpenRAVE emits are (rightfully) kinematic models (chap. 10, p. 435
> > of Collada spec). These are apparently not supported by the Collada
> > Blender importer. It should be however quite doable to add this feature
> > to the importer (since it has similar effects as the existing skeleton
> > system).
> >
> > You may want to give it a look...
> >
> > Cheers,
> > Severin
> >
> > On 02/06/2013 02:24 AM, William Hilton wrote:
> >> Hi Severin,
> >> I started looking at the actual XML, and have decided COLLADA is more
> >> complicated than I would have thought! There may be multiple ways to
> >> define an armature, and maybe my .dae file doesn't do it in a way
> >> Blender understands. Honestly, I don't know if the problem lies in
> >> Blender's import. For all I know, it could be in how OpenRAVE exports
> >> the model to .dae.
> >>
> >> Here's the file I am trying to use. It's 6MB so I'll put it in Google
> Docs.
> >>
> https://docs.google.com/file/d/0B7vT3fhK-GBERGVDc0lWTVpBZnM/edit?usp=sharing
> >> Will
> >>
> >> --
> >> William Hilton
> >> MET-lab PhD Student, ECE Department, Drexel University
> >> Website: http://music.ece.drexel.edu/people/wmhilton
> >> Email: wmhilton at drexel.edu <mailto:wmhilton at drexel.edu>
> >> SMS: 513-368-5411
> >>
> >>
> >> On Tue, Feb 5, 2013 at 3:24 PM, Séverin Lemaignan
> >> <severin.lemaignan at laas.fr <mailto:severin.lemaignan at laas.fr>> wrote:
> >>
> >>     After some collada + armatures testing (namely, exporting
> >>     kuka_arm.blend to collada and re-importing, and importing this
> >>     collada file [1], with blender 2.65a), I get mixed results:
> >>     the Kuka model is garbage when I re-import it, while the collada
> >>     sample [1] looks fine.
> >>
> >>     So it is possible the Blender Collada *exporter*  does not work well
> >>     with armatures. Can you share a collada model you would like to
> import?
> >>
> >>     Cheers,
> >>     Severin
> >>
> >>     [1]
> >>
> >> http://anima-animation-sample.__
> googlecode.com/svn-history/__r11/trunk/Models/cubes2.dae
> >>
> >> <
> http://anima-animation-sample.googlecode.com/svn-history/r11/trunk/Models/cubes2.dae
> >
> >>
> >>
> >>     On 05/02/2013 20:15, William Hilton wrote:
> >>
> >>         Yes, I should have mentioned I am using the latest version of
> >>         Blender
> >>         (2.65a).
> >>
> >>
> >>
> >>     --
> >>               Séverin Lemaignan - severin.lemaignan at laas.fr
> >>     <mailto:severin.lemaignan at laas.fr>
> >>
> >>       [00]    Post-doctoral fellow in Cognitive Robotics
> >>     /|__|\   LAAS-CNRS - RIS group
> >>        '' +33561337844 <tel:%2B33561337844>
> >>     http://www.laas.fr/~slemaign
> >>
> >>
> >
> > --
> >            Séverin Lemaignan - severin.lemaignan at laas.fr
> >    [00]    Post-doctoral fellow on Cognitive Robotics
> >   /|__|\   LAAS-CNRS - RIS group
> >     ''     +33561337844
> >            http://www.laas.fr/~slemaign
> > _______________________________________________
> > Robotics mailing list
> > Robotics at blender.org
> > http://lists.blender.org/mailman/listinfo/robotics
> >
>
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