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Yep, we had a discussion on this a while back. I needed exactly what you are proposing now:
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A multibody robot model with forward kinematics calculation based on joint angles.
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At that time we agreed with the Mars people that this would be a good interface for starting to use the same visualisation between mars and vizkit.
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I did a hack back then for mars models, which is in simulation/mars_viz.
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In any case, I think we discussed several ways of how we could introduce this in rock:
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(a) Vizkit plugin, that takes URDF/Collada/whatever file as a parameter, and joint angles as input type. Least amount of effort, but only useful for visualization.
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(b) A more tightly integrated approach, that takes the transformer into account. I think our general way of configuring and setting up robots would benefit from this, too.
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this might benefit from further discussion and could be a good opportunity to get different parts working together.
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cheers,
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</div> Jakob
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<br/>On May 7, 2013 at 4:44 PM Matthias Goldhoorn <matthias.goldhoorn@dfki.de> wrote:
<br/>> Collada was several times an good candidate not only for the
<br/>> visualization also for mars (also the physics/sim part).
<br/>> Since noone has time to to this this get forgotten.
<br/>> If you have some free recources please grap the discussion on
<br/>>
<br/>> http://rock.opendfki.de/wiki/WikiStart/OngoingWork/RobotDescriptionFile
<br/>>
<br/>> and reply to the ML. Malte L. (ex. R.) was invited to because there was
<br/>> some open questions for/with mars but i not remember them yet.
<br/>>
<br/>> If there _are_ free recources we should definelty define an wider used
<br/>> and accepted format. There was several limitations on URDF (see link
<br/>> above).
<br/>>
<br/>> Matthias
<br/>>
<br/>> On 07.05.2013 16:38, Sylvain Joyeux wrote:
<br/>> > -------- Original Message --------
<br/>> > Subject: Re: Robot visualization in Vizkit3D
<br/>> > Date: Tue, 07 May 2013 15:47:33 +0200
<br/>> > From: Sylvain Joyeux<sylvain.joyeux@dfki.de>
<br/>> > Organization: DFKI RIC
<br/>> > To: Malte Wirkus<malte.wirkus@dfki.de>
<br/>> >
<br/>> > On 05/07/2013 09:56 AM, Malte Wirkus wrote:
<br/>> >> for a software project I am working on, I am developing a visualization
<br/>> >> of multi-body robots based on Open Scene Graph (OSG).
<br/>> >> Since I did not find something similiar in ROCK's Vizkit3D, I wonder if
<br/>> >> you might be interested if I make this available as a Plug-In for Vizkit?
<br/>> >>
<br/>> >> Here are some maybe relevant things about it:
<br/>> >>
<br/>> >> * As robot description format it used URDF
<br/>> >> (http://www.ros.org/wiki/urdf)
<br/>> >> * For kinematic calculation, KDL is used
<br/>> >> (http://www.orocos.org/wiki/orocos/kdl-wiki)
<br/>> >> * Therefor there are dependecies on OSG, URDF, a URDF parser library, a
<br/>> >> URDF to KDL parser library
<br/>> >> * All these libraries but OSG are available in ROS
<br/>> >> * It makes use of the ressource_retriever from ROS
<br/>> >> (http://ros.org/wiki/resource_retriever), but can also be used
<br/>> >> without. Absolute paths to the 3D meshes have to be set in the URDF
<br/>> >> file then.
<br/>> >>
<br/>> >> Forward kinematics are calculated within the visualization. Practically
<br/>> >> that requires joint data (current positions) as input for the plug in.
<br/>> >> Having it as part of ROCK one could also say that forward kinematics are
<br/>> >> calculated elsewhere, and the input for the plugin would be 3D poses for
<br/>> >> each link of the robot. This is the way they do it in ROS (with RVIZ,
<br/>> >> http://www.ros.org/wiki/rviz).
<br/>> >>
<br/>> >> Regards,
<br/>> >>
<br/>> >> Malte
<br/>> >
<br/>>
<br/>>
<br/>
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