[Opensim-dev] Using ODE for vehicles and ragdolls

[Stefan Andersson]

I for one would love to see it unfold something like this
 
1) one or several prototypical and specialized implementations coding directly to ODE but in a nice manner.
2) the implementations refactored into a nice OpenSim API for ODE joints
3) one or several implementations of vehicles utilizing this API directly
4) these implementations refactored into a nice OpenSim vehicle API
5) implementing the LSL vehicle model using this API
so yeah, bottom up is the way to go, but with a clear goal in the back of our heads.
 
I for one would want to see the monorail module before the monorail lsl script.
 
I also suspect that along the lines, we might see that we want to implement vehicle types that don't fit into the lsl model... like the 'humanoid' or 'animal' - anybody up for building a stone giant or re-casting an agent in pure prims? :D Best regards,Stefan AnderssonTribal Media AB Join the 3d web revolution : http://tribalnet.se/ > From: adam at deepthink.com.au> To: opensim-dev at lists.berlios.de> Date: Wed, 19 Nov 2008 02:01:27 -0500> Subject: Re: [Opensim-dev] Using ODE for vehicles and ragdolls> > Doesnt ODE have vehicle support internally? The concern I'd have about a vehicle layer over the top might be that performance is suboptimal since we need to run a second physics step which could introduce issues.> > Regards,> > Adam> > > -----Original Message-----> > From: opensim-dev-bounces at lists.berlios.de [mailto:opensim-dev-> > bounces at lists.berlios.de] On Behalf Of Gerhard Dünnebeil> > Sent: Tuesday, 18 November 2008 10:40 PM> > To: opensim-dev at lists.berlios.de> > Subject: Re: [Opensim-dev] Using ODE for vehicles and ragdolls> >> > Hi> >> > having looked into the ODE engine I don't think it's usable for the> > vehicle API.> >> > Instead i think we should put the vehicle engine on top of it.> >> > This is pretty easily done by adding another layer (could/should be in> > a> > plugin).> > It can be called in each "Simulate" step and calculate the forces> > needed> > to achieve the vehicles behaviour.> > These forces are then applied -- using the phys engine's API -- to the> > objects.> >> > This way we are> > a) ... independant (at least theoretically) from the characteristics of> > the underlying Phys engine> > b) ... able to implement different engines for different purposes> >> > I know someone (is it you, nlin?) already implemented a sailing boat in> > OpenSim. A modular approach here would allow us to implement> > alternative> > friction models beyond what LSL gives us.> >> >> > Just my two cents> >> > Gerhard> >> >> > nlin (message) wrote:> > > Hello,> > >> > > There's been some discussion about SL-compatible vehicles in OpenSim> > > recently, with its higher-level abstraction of how vehicles work.> > This> > > would have the long-term goals of compatibility and ability to swap> > > out physics engines while still using the same vehicle layer.> > >> > > SL-compatibility and abstracting vehicles from the physics engine are> > > good goals for the long term; sort of a top-down approach (start with> > > the vehicle abstraction, map it to many different physics engines).> > >> > > Complementary to this, I'd like to explore and start discussion of an> > > alternative way of handling vehicles by using a bottom-up approach.> > > Starting with the specific physics engine of ODE, can we use> > > ODE-specific features to make simple vehicles?> > >> > > I did some experiments with OpenSim and ODE and the answer seems to> > be> > > yes, we can make simple vehicles with ODE by using joints. We can> > also> > > make ragdolls. I posted some videos to YouTube of the preliminary> > results:> > >> > > http://www.youtube.com/watch?v=iYIh-eIwmjs> > > http://www.youtube.com/watch?v=z9bedzIuxdM> > >> > > This is only prototype work for now, put together sort of quickly as> > a> > > proof-of-concept with just enough "plumbing" (data flow) to work.> > > There are a number of issues that need to be solved for this to work> > > cleanly. As far as I know (please correct me if I'm wrong) there> > > hasn't been much work done to try to get ODE joints/vehicles/ragdolls> > > working in OpenSim, but I think it's an avenue worth exploring.> > >> > > Is there interest in pursuing this approach for OpenSim vehicles? I> > > would look forward to discussing some of the issues that would need> > to> > > be solved.> > >> > > Thanks,> > > N Lin (nlin)> > >> > > ---------------------------------------------------------------------> > ---> > >> > > _______________________________________________> > > Opensim-dev mailing list> > > Opensim-dev at lists.berlios.de> > > https://lists.berlios.de/mailman/listinfo/opensim-dev> > >> >> > _______________________________________________> > Opensim-dev mailing list> > Opensim-dev at lists.berlios.de> > https://lists.berlios.de/mailman/listinfo/opensim-dev> _______________________________________________> Opensim-dev mailing list> Opensim-dev at lists.berlios.de> https://lists.berlios.de/mailman/listinfo/opensim-dev
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