Thanks Dahlia :) On Fri, Dec 5, 2014 at 4:05 PM, Dahlia Trimble <[email protected]> wrote:
> A lot depends on where the "physical" (moving, rigid objects or avatars) > are relative to the static (non-movable) non-phantom objects. Collision > testing can be a significant part of simulation load. It generally happens > in multiple phases: a "broad phase" where any moving objects' sizes and > positions are compared to other objects to see if they are close enough to > warrant more precise testing, and a "narrow phase" where any potentially > colliding surfaces are tested. If your scene is set up so that you have > many complex collidable (non-phantom) static objects but all of your > avatars are not near them then collision testing load should be fairly low. > However if they are all standing on colidable objects made of hundreds of > small prims then collision testing load will be much higher. Some prims > and/or mesh models can have thousands of triangles which could each be > subject to collision testing. > > In general if you have very complex objects it's probably better to make > them phantom and superimpose a simpler, invisible shape which can be used > for collisions. The mesh uploader in most viewers offers an optional > "physics mesh" which could be used for this purpose as well. However, if > simulation CPU load is not an issue for you then you could probably get > away with ignoring such optimizations although considering how content is > often repurposed it could be considered a best practice to use them. > > On Fri, Dec 5, 2014 at 12:16 PM, Dr Ramesh Ramloll <[email protected]> > wrote: > >> Hello there, >> As I was reading about opensim performance on the opensimulator.org >> site, I came across these two recommendations >> >> - Make as many objects phantom as possible. Phantom objects do not >> need to be tested for collisions with avatars and other objects, reducing >> physics frame time and increasing performance. >> - Make as few objects subject to physics (e.g. falling under gravity, >> movable by other avatars) as possible. Physics objects need a lot more >> collision testing than ordinary non-phantom objects. >> >> >> I understand these appear fairly logical. I am curious though, are these >> differences really going to make perceptible improvements in user >> experiences? Are there any metrics that would say help us know when to >> start converting unnecessarily physical objects to phantom? >> Thanks >> Ramesh >> -- >> 'Consider how the lilies grow. They do not labor or spin.' >> *Rameshsharma Ramloll* PhD, CEO CTO DeepSemaphore LLC, Affiliate *Research >> Associate Professor*, Idaho State University, Pocatello, ID 83209 Tel: >> 208-240-0040 >> LinkedIn <http://www.linkedin.com/in/rameshramloll>, DeepSemaphore LLC >> <http://www.deepsemaphore.com>, RezMela <http://www.rezmela.com>, Google+ >> profile <https://plus.google.com/103652369558830540272/about> >> >> _______________________________________________ >> Opensim-users mailing list >> [email protected] >> http://opensimulator.org/cgi-bin/mailman/listinfo/opensim-users >> >> > > _______________________________________________ > Opensim-users mailing list > [email protected] > http://opensimulator.org/cgi-bin/mailman/listinfo/opensim-users > > -- 'Consider how the lilies grow. They do not labor or spin.' *Rameshsharma Ramloll* PhD, CEO CTO DeepSemaphore LLC, Affiliate *Research Associate Professor*, Idaho State University, Pocatello, ID 83209 Tel: 208-240-0040 LinkedIn <http://www.linkedin.com/in/rameshramloll>, DeepSemaphore LLC <http://www.deepsemaphore.com>, RezMela <http://www.rezmela.com>, Google+ profile <https://plus.google.com/103652369558830540272/about>
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