[Robotics] COLLADA 1.5 armature support?
ulbrich at ira.uka.de
ulbrich at ira.uka.de
Thu Feb 7 11:22:36 CET 2013
Hi Will,
> 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?
Okay, I got you wrong then. I guess it will be difficult to do it
without the export -- although I can imagine some ways. Both Blender
and OpenRAVE are Python-based so you probably could write a script
using both simultaneously. I tried something slightly similar (but
without Blender) a while ago but I could not access the colors of the
faces; only their geometry.
If there is no strong argument against the Collada-export, we could
try to fix the import. In theory, it won't require much work as the
most complicated part -- the extraction of the kinematic / dynamic
model -- already works. That way, I can make sure that it can cope
OpenRAVE's generated files.
BTW, the COLLADA specific part of the RobotEditor is quite generic, so
it could be integrated into other projects easily.
Best,
Stefan
> --
> 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 The version on this homepage is outdated and works only with blender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
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>> >
>>
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