Bullet physics ready for testing

Bullet physics is ready for testing, and is now part of the OpenSim core code, according to Intel’s Robert Adams.

Turning on Bullet physics is as simple as changing the OpenSim.ini file, replacing the line “”physics = OpenDynamicsEngine” with “physics=BulletSim”.

It does require access to the OpenSim region server, so in order to test Bullet physics, you either need to be running OpenSim on your own computer, or have your hosting company make the change.

“While this is an ongoing effort that will see continuous improvement, I am working toward BulletSim running well enough that it could become the default OpenSimulator physics engine within the next few months,” Adams told Hypergrid Business. “I encourage everyone to test BulletSim and file any problems in the OpenSimulator bug database.”

The Bullet physics engine is more actively maintained than the Open Dynamics Engine that is the current default in OpenSim, and offers better performance while still being free and open source. It is also being used in many high-profile projects.

For example, the Bullet physics engine was used in the Toy Story 3 video game, Grand Theft Auto IV, Sony’s Free Realms games, and Activision’s Blood Drive.  It also shows up on the big screen, where it was used for special effects in such movies as “Hancock,” “The A-Team,” “Sherlock Holmes,” “Megamind” and “Shrek 4.” It is also used in Blender for animations.

BulletSim is the version of the Bullet physics engine optimized to work with OpenSim.

Adams said that he’s currently working on two areas, improving performance, and making vehicles work better in OpenSim.

For example, BulletSim supports linked objects, such as chains.

And BulletSim supports a larger number of objects, such as in the following video with 1,000 blocks.

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Maria Korolov

Maria Korolov is editor and publisher of Hypergrid Business. She has been a journalist for more than twenty years and has worked for the Chicago Tribune, Reuters, and Computerworld and has reported from over a dozen countries, including Russia and China.

  • Harriet Inglewood

    That is exciting news indeed! I bet it won’t be long until Bullet is available as an option in Kitely. That would be a blast, physical vehicles running on advanced megaregions without sim borders. Gentlemen….. start your engines 🙂

    • Minethere

      I find this very exciting and have kept an eye on the progress-)) As I understand it, this will also open up sim crossings to vehicle scripts finally…or, am I wrong? hehe

      • Harriet Inglewood

        You are correct. There are no sim borders within a megaregion, it’s all one huge region. That means no ‘rubber band effect’ when crossing borders if the vehicle is physical or hesitation at the border if the vehicle is non-physical. Crossings don’t get better than that anywhere regardless of the script/ physics engines. Plus you don’t have to worry about losing controls or the ability to turn your avatar after using a vehicle – unlike some other commercial OS grid.

        • Minethere

          well, i wasn’t referring to mega-region crossings..that’s a different critter altogether…and of course your referring to inwz and its border crossing issues..i am well aware of that as i did it often [tho it has been a couple of months since the last time i tried]..i am referring to, specifically, os grid based sim crossings finally of vehicles-))

        • Just to butt in with an FYI 🙂 AuroraSim uses something called variable regions which allows the grid owner/operator to define the size of any given region. A 16megaregion on OpenSim would be a single 1,024meter region on AuroraSim, with absoulty no region crossings since its all one region.

  • I am looking forward to giving this a try. Just waiting on the next development release. I am also thinking of promoting its adoption as an optional physics engine for AuroraSim.

    • hack13

      Why? Aurora-Sim’s physics is amazing, and I mean pretty damn amazing. I can do all that without the lag I am seeing in these videos on aurora…

      • More along the lines of having options. And the changes to the AuroraSim Physics Engine have caused me some troubles.

        And what if it turns out that BulletSim is superior?