[Opensim-dev] [Non-DoD Source] Re: PhysX vs. BulletSim vs. ODE

Fri Feb 5 18:27:16 UTC 2016

Hello Douglas
Interesting progress report. Is there any timeline available for if or when
others can configure and profile the system?
Zadark

On 5 February 2016 at 18:00, Maxwell, Douglas CIV USARMY RDECOM ARL (US) <
douglas.maxwell3.civ at mail.mil> wrote:

> Thank you for your feedback, Michael.  As you know, the OpenSimulator is a
> very complex system.  It is very important for us to isolate as many
> variables as possible to present a responsible comparison analysis of the
> three engines.  Sean presented the performance of the engines with the
> OpenSim configured as "stock".
>
>
>
> You are absolutely correct, using the "UseSeparatePhysicsThread" flag does
> improve performance.  It is just one of the variables we are examining to
> determine the affect of the physics engine on the overall system.  Sean was
> reporting that there were significant increases in performance during the
> baseline testing.  By carefully and systematically changing the variables
> in the system, we can determine which variables have the most impact
> differentiation from the baseline as well as what affect each variable has
> on each engine.
>
>
>
> I realize this looks like tedious work, and it is.  However this approach
> allows us to profile and examine the code so that meaningful changes can be
> made for the better (not accidentally stumbling upon a combination of
> variables).    As an Enterprise level user, we need the ability to predict
> how the simulator will behave under different loads so we can plan and
> provision for different usage scenarios.
>
>
>
> In the very near future we will be releasing our distributed PhysX code as
> well.  This functionality will allow you to dedicate a separate server to
> the physics engine and scale it vertically as appropriate.  We can discuss
> the implications for scaled performance as well as tradeoffs in network
> performance at that time.
>
>
>
> Lastly, we have specific needs that BulletSim cannot accommodate.  The
> decision to choose PhysX for integration was done deliberately.  If you
> would like to join us at the MOSES office hours or contact me directly, we
> can discuss in detail.
>
>
>
> Have a great weekend.  v/r -doug
>
>
>
>
>
>
> Douglas Maxwell, Ph.D.
> Science and Technology Manager
> Virtual World Strategic Applications
> U.S. Army Research Lab
> Human Research & Engineering Directorate
> (c) (407) 242-0209 <%28407%29%20242-0209>
> ------------------------------
> *From:* opensim-dev-bounces at opensimulator.org [
> opensim-dev-bounces at opensimulator.org] on behalf of Michael Emory
> Cerquoni [nebadon2025 at gmail.com]
> *Sent:* Wednesday, February 03, 2016 11:10 AM
> *To:* opensim-dev at opensimulator.org
> *Subject:* [Non-DoD Source] Re: [Opensim-dev] PhysX vs. BulletSim vs. ODE
>
> All active links contained in this email were disabled. Please verify the
> identity of the sender, and confirm the authenticity of all links contained
> within the message prior to copying and pasting the address to a Web
> browser.
>
> ------------------------------
>
>
> I have had over 100,000 physical spheres in Bulletsim without a crash and
> was still able to log in, move around and erase all the objects and have
> performance go back to normal, you need to enable running it in its own
> Thread, to achieve this level of performance. to enable this feature in the
> [BulletSim] section of OpenSim.ini add :
>
> UseSeparatePhysicsThread = true
>
>
> On Wed, Feb 3, 2016 at 10:56 AM, Sean M <mondesire.sean at gmail.com
>  < Caution-mailto:mondesire.sean at gmail.com > > wrote:
>
>> Greetings,
>>
>> The MOSES Team has been working on integrating NVIDIA's PhysX physics
>> engine into OpenSim. Once complete, this integration will give OpenSim grid
>> administrators the option of selecting the new engine for their own worlds.
>>
>> Prior to releasing the complete integration, the team has begun
>> extensively testing and analyzing the engine's performance. We are pleased
>> to report that PhysX significantly improves OpenSim's ability to support
>> more physical objects than BulletSim and ODE. Our analysis ran under
>> controlled and repeated testing (30 independent OpenSim executions per
>> engine) that isolated physics engine related variables. Under these
>> conditions, PhysX supported 86% more physical objects than BulletSim (the
>> OpenSim default physics engine) before the simulation's performance starts
>> to noticeable degrade. More specifically, before dropping below 9
>> simulation frames per second (SimFPS), PhysX supported 3,300 physical
>> objects (AtvPrm), BulletSim 1,800, and ODE 200. The reported SimFPS did not
>> use the correction factor; therefore, the highest frame rate was 11.33
>> frames per second. Attached is a graph of the performance of the three
>> physics engines as 5,000 physical objects were generated in the simulation.
>> All experiment details will be available in the 2016 proceedings of MODSIM
>> World.
>>
>> Again, we are very pleased with the result and believe everyone will
>> benefit from the effort. An announcement will be made in a few days to
>> indicate when the final integration code will be available on the MOSES
>> public GitHub.
>>
>> Thank you,
>> Sean Mondesire
>> MOSES Team
>>
>> [image: Inline image 1]
>>
>> _______________________________________________
>> Opensim-dev mailing list
>> Opensim-dev at opensimulator.org < Caution-mailto:
>> Opensim-dev at opensimulator.org >
>> Caution-http://opensimulator.org/cgi-bin/mailman/listinfo/opensim-dev
>>  < Caution-http://opensimulator.org/cgi-bin/mailman/listinfo/opensim-dev
>>  >
>>
>>
>
>
> --
> Michael Emory Cerquoni
>
> _______________________________________________
> Opensim-dev mailing list
> Opensim-dev at opensimulator.org
> http://opensimulator.org/cgi-bin/mailman/listinfo/opensim-dev
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://opensimulator.org/pipermail/opensim-dev/attachments/20160205/4c3959b7/attachment-0001.html>