I believe there is a means in the LLUDP protocol to stuff many updates for many objects into a single packet, though I'm not sure OpenSimulator is smart enough to do it in your simulation. It may be a way to improve networking performance quite a bit when may physical objects change velocity during the same simulation frame.
On Tue, Apr 14, 2015 at 1:44 PM, steve l <[email protected]> wrote: > Hi! > > Robert- Thanks for the answer and the thought you put into it! > > So I am going to play dummy (Not far from the truth!) here. This means > that we need to do re-writing on several parts of OS to speed things up and > eliminate bottlenecks. a couple of questions then. > > 1. Is the explosion of blocks or prims something that the viewer can > handle? Or is this too tricky to make happen with the wide variations of > machine running viewers and even more so that soon the viewer will run in a > web browser? > > 2. Is there a way to make the explosion an overlay streaming event that > runs over the current screen? - Just a crazy idea.... I am thinking of this > more on a browser-viewer as that needs to run on devices that would have > issues processing all that... > > 3. Is it possible to make OS Physics run faster than 11FPS? > > 4. It seems that the number of avatars exponentially changes the workload > here. Maybe a graphics server could be designed as a sub service to handle > that type of load, maybe running on a GPU instead of a CPU? It just seems > to me that with all the other things that the region server has to do, > offloading some of the heavy lifting would be a good thing. Maybe it is > time to think of an OS "Pro" level of setup that separates the workload a > bit more would be a good idea. > > These things always get me thinking...! > > Steve LaVigne > A Dimension Beyond, Inc. > www.adimensionbeyond.com > > On Tue, Apr 14, 2015 at 10:45 AM, Adams, Robert <[email protected]> > wrote: > >> I don’t think the only problem is finding a physics engine that can >> handle 240 moving objects. Another is optimizing the updates from the >> physics engine. >> >> >> >> Think of the whole pipeline: the physics engine computes interactions and >> new locations/rotations for each object. That position update is sent to >> the simulator. The simulator updates the object data structures and sets an >> update flag. The location/position update is noticed and an update >> packet[1] is created and placed in output queues for each viewer. At some >> time, the packet is transmitted to each viewer. >> >> >> >> The update processing time can easily be more than the physics engine >> time. >> >> >> >> The OpenSimulator physics engines are run 11 times a second so they >> generate 11 position updates a second for each moving object. So, even an >> efficient physics engine will generate (240 * 11) updates per second which >> then turn into (240 * 11 * numberOfAvatars) packets sent per second. >> >> >> >> There are many optimizations possible in this chain. >> >> >> >> -- mb >> >> >> >> [1] This is technically wrong for the current version of OpenSimulator. >> For the technically inclined, an ‘update needed’ packet is put in the >> output queue and the actual packet to transmit is created when it is time >> to send the update. This is done because the update output packet queue can >> get long and the position/location information can be stale if multiple >> updates are in the queue. Only one ‘update needed’ packet is put in the >> queue and the current object location/rotation is put in the transmitted >> packet at the time of transmission. >> >> >> >> *From:* [email protected] [mailto: >> [email protected]] *On Behalf Of *steve l >> *Sent:* Tuesday, April 14, 2015 8:09 AM >> *To:* Michael Emory Cerquoni >> *Cc:* [email protected]; [email protected] >> *Subject:* Re: [Opensim-dev] New MOSES Physics Video >> >> >> >> Hi! >> >> An excellent video on the physics of exploding grenades and the wall. On >> the OS Dev list Mister Blue has an excellent observation that the server >> crashes are due to the extreme amount of changes that have to be sent to >> every avatar. His idea of a client side solution might just be a good one. >> In the end is there any way that OpenSim can handle more events than that >> in it's present form? Is there any physics engine that can handle 240 >> moving scripted objects moving at once without lag? >> >> If we could get OS to the point that it would handle this load easily, we >> would have all our load issues solved! >> >> Steve LaVigne >> >> >> >> On Tue, Apr 14, 2015 at 6:33 AM, Michael Emory Cerquoni < >> [email protected]> wrote: >> >> Could these test scripts be shared so testing against other engines can >> occur as well, I would be interested to see how this same test goes against >> ODE and BulletSim as well. >> >> >> >> On Tue, Apr 14, 2015 at 8:18 AM, Maxwell, Douglas CIV USARMY ARL (US) < >> [email protected]> wrote: >> >> Good Morning, as you all know the MOSES developers are working on >> PhysX integration into the Open Simulator to support functionality >> currently not possible in the platform. We are a methodical group and a >> couple months ago I asked one of our interns to work with the developers to >> create a series of baseline physics behavior case studies. The first case >> study is a destructible wall caused by an explosive charge. This wall is >> composed of blocks that are tested at a high density and a low density to >> simulate different destruction effects. >> >> >> >> The goal here is to eventually have all of the prims in the sim loaded >> with the scripts needed to react to any type of random explosive charge set >> by the participants in the training scenario. >> >> >> >> The video can be found below: >> >> >> >> https://youtu.be/jSofWcwWi7g >> >> >> >> Your feedback is welcome. >> >> >> >> Observations: >> >> 1) Current limitations of the open simulator prevent us from expanding >> the tests beyond a simple wall. >> >> 2) The scripts exercise the engine well and expose limitations between >> the sim frame rate and the physics frame rate. >> >> 3) It is easy to crash the sim with this demonstration, especially if >> more than a handful of people are present (more than 3-4 client >> connections). >> >> >> >> Douglas Maxwell, MSME >> Science and Technology Manager >> Virtual World Strategic Applications >> U.S. Army Research Lab >> >> Human Research & Engineering Directorate >> Simulation & Training Technology Center >> (c) (407) 242-0209 <%28407%29%20242-0209> >> >> >> >> _______________________________________________ >> Opensim-dev mailing list >> [email protected] >> http://opensimulator.org/cgi-bin/mailman/listinfo/opensim-dev >> >> >> >> >> -- >> >> Michael Emory Cerquoni >> >> >> > > > _______________________________________________ > Opensim-dev mailing list > [email protected] > http://opensimulator.org/cgi-bin/mailman/listinfo/opensim-dev > >
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