> Indeed. But rather, it is not about "extending", but integrating two (or > more) different sets of functionalities. This may prove to be a difficult challenge indeed. The two libraries have significant difference in representation. I would love to discuss it with you and Karen together - though I'm really not sure that this whole conversation needs to continue to spam the ros-users list - unless folks are really that interested. > Have you ever asked about it? Or made suggestions? That's how open source > projects work :-) I think part of open source is that "how it works" is open to interpretation :0} Honestly, at the time I was looking ~08-09 there were no concrete plans to add dynamics to KDL. There was this confusing comment chain: http://www.orocos.org/node/735 which I now find to be even more confusing. More recently, I checked again on the KDL page and documentation and there was no mention of any forward/inverse dynamics. Even now dynamics are not mentioned and all the examples are purely kinematic. At the same time, working with Karen we have a complete dynamic solver with lots of examples (just not releasing until we complete the contact handling) - i.e. have a full open source dynamic simulator with both dynamic solvers in generalized coordinates and contact resolution. It will be accompanied by documentation and fully BSD. > I react to your posting, and the same thing could/should happen for you > with things KDL might or might not provide in the future. Basically there was intermittent discussion about dynamics in KDL on the web and it did not appear that there was a final solution in place after a couple years of development. Mostly "experiental." I'm aware of those discussions - but I was looking for a tested dynamics solution that we could use directly and hence now we have one. > If you have unit test cases, and want to share them with others, that > would be a nice contribution to the community. Abslutely we will have lots of test cases to share. The library should definitely be entirely open with lots of examples. > These are _integration_ issues, which should not be done by extending one > single library. Otherwise, we end up where we have ended up for decades > already: huge monolithic libraries that are not interoperable. I really do think this is a longer discussion. Maybe even one to have in person. Will you be at IROS? > I'm looking forward to these things. Within KDL we are now trying to use > Collada the standard data format to represent kinematic chains. (And to > couple it to other functionalities such as controllers.) Yup, same here. Collada and URDF actually to support multi-resolution meshes and sensors. Probably starting with Collada first. >> Exactly, so I would consider a force/impedance controller to be a tool >> that may benefit from the dynamics of the library or the collision >> checking library or neither or both. I see no reason to force the tools >> (algorithms) built on top of the basic solvers to be constrained in any >> particular way. > Agreed! Great! > What does "join the SIG means"? Yet another mailinglist? At the moment it means go to this wiki: http://www.ros.org/wiki/fuerte/Planning And add your name to Section 2.10 ------------------------ Here's a forward of what this means from Sachin The signup period will last until September 14th. After the signup period, any SIG that has at least two people signed up for it will be considered valid. If you are proposing a SIG, we urge you to recruit authors/maintainers of the relevant software -- the authority of what goes in/out of a library remains with the maintainer/author, so their buy-in is crucial. Similarly, we encourage authors/maintainers to signup for SIGs that are relevant to their software. The follow-up process is also very simple: 1. Each SIG designates a SIG Coordinator. If an SIG cannot agree on a coordinator, one will be chosen for you. 2. The coordinator will organize planning meeting(s) for the SIG. This can be over IRC, video chat, at IROS, or whatever medium bests fits the composition of your SIG. The deadline for these meetings is September 28th. 3. Each SIG group will post their planning notes as a sub-page of http://ros.org/wiki/fuerte/Planning/. The deadline for posting these notes is September 30th. SIGs can have followup meetings, but this initial deadline is to ensure that the SIG is activated. The plans are just that -- plans. It is up to the members of each SIG to achieve as much of that plan as possible in time for the freeze dates of ROS Fuerte (remember, there's always Groovy Galapagos). As always, we appreciate your participation. We hope this more distributed process will better match the distributed nature of ROS development.