GDC 2009 Physics Tutorial on CUDA, SPU, OpenCL and Larrabee optimizations


We have been working for a while on parallel physics optimizations for various platforms. As part of the Math and Physics Tutorial on Tuesday March 24th, Takahiro Harada and Erwin Coumans will do a joint presentation that discusses our experiences how to optimize a rigid body physics pipeline for CUDA, SPU, Larrabee and OpenCL.

Bullet 2.74 released: constraint limit debug visualization

Bullet 2.74 physics sdk has been released and can be downloaded from the Google Code website.


Constraint debug visualization has been added to make it easier to setup constraint limits. Other improvements include SIMD constraint solving, buoyancy demos, single-shot multiple contact point generation, improved documentation etc.

IEEE VR 2009 Tutorial on Interactive Physics Simulation


This tutorial presents the different components required in real-time physical-based simulations. It covers a broad scope of topics while discussing a few recent developments, allowing attendees to see and understand what is currently possible to integrate physics within a virtual environment. We focus on practical methods, as implemented in publicly available toolkits. It is mainly intended as an introduction for anyone interested in integrating physical behaviors in virtual environments, but the recently published interactive simulation technics that are presented might also be of interest to more experienced participants.

  • Jeremie Allard – Research Scientist at Alcove, INRIA Lille
  • Francois Faure – Assistant Professor at Evasion, Grenoble Universities.
  • Erwin Coumans – Simulation team lead at Sony Computer Entertainment America
  • Kenny Erleben – Assistant Professor at DIKU, University of Copenhagen
  • Richard Tonge – Senior Software Engineer at NVIDIA

For more information or to attend visit

Bullet 2.73 released: fast btCudaBroadphase

Bullet 2.73 has been released, download from


For 8192 fast moving objects on NVidia 8800 GTX, Intel Core 2 3Ghz: CUDA (btCudaBroadphase) 6ms, OPCODE Array SAP 37ms, Bullet dynamic BVH (AABB tree, btDbvtBroadphase): 12ms. When nothing moves, the CUDA broadphase still takes 4ms, whereas SAP and dynamic BVH (btDbvtBroadphase) are practically 0ms. For even larger amounts of moving objects (64k) the CUDA still performs fine, whereas SAP/dynamic BVH grind to a halt. This makes it a good candidate broadphase for environments with huge destruction.

Thanks to everyone for feedback, bug fixes and improvements!

Bullet presentation @ GDC Austin, Monday September 15th 2008


  • Developing Games with Open Source Technologies: Full-day Tutorial
  • Monday, September 15th Austin Convetion Center, Room 9C
  • 11:00am – 11:50am: Tumbling, falling and breaking: Bullet open source, professional physics engine

Open source technologies bring cutting edge innovation, source code accessibility, rich community support, and a pricetag that can’t be beat to developers in every industry — including the online game industry. In this one day mini-track you will learn first hand from leading game developers and technology providers about open source game engines, tools, and server technologies that are changing the economics of online game development today.

Bullet 2.71 released: Disney Maya Plugin, CUDA experiments

Download here

Apart from numerous bug fixes, this is new:

  • Walt Disney Studios contributes their in-house Dynamica Maya Plugin for Bullet physics simulation.
  • Check out the Dynama Maya Plugin instruction videos.
  • This Dynamica Plugin is used in Disney’s upcoming 3D animated movie Bolt, for example in the peanuts shot below.
    Thanks to Nicola Candussi and Arthur Shek from Disney for this contribution!
  • Several bug fixes and contributions related to inertia tensor, memory leaks etc.
    Thanks to Ole K and several other contributors.
  • Added btCudaBroadphase in Extras/CUDA: some preliminary research into accelerating Bullet using CUDA.
    Thanks to the particle demo from the NVidia CUDA SDK.
  • Updated CDTestFramework, with latest version of OPCODE Array SAP. See Extras/CDTestFramework
    Thanks to Pierre Terdiman for the update
  • ForkLiftDemo has been finished, finally!
  • Improved performance for btDbvtBroadphase.
    Thanks to Nathanael Presson again, for all his work.


OLPC Physics Game Jam

OLPC is hosting a Physics Game Jam in Boston from August 29 to 31.

This is a team based rapid game development competition based on creating a physics game for OLPC XO laptops in 48 hours. Remote entries are allowed, and there will be prizes for the winners. PyBox2D is the main physics library that will be used, but anything open source that will run on the XO is fine.

There will be programming workshops such as developing in Sugar, using PyBox2D, and integrating computer vision with physics, so prior experience is not a requirement.

There is more information on the OLPC Wiki:

Registration is free, but donations are encouraged:

Bullet @ SIGGRAPH 2008

We are visiting SIGGRAPH again next week.

Some of the Bullet/physics related activities:

  • There will be a Bullet presentation at the Sony booth #521 (exhibition hall) Tuesday, Wednesday and Thursday from 14.15-14.45.
  • We will do a short COLLADA Physics presentation at the COLLADA BOF, Thursday, 14 August | 4:00 pm – 6:00 pm | LACC – Room 511A.
  • And present about Bullet integration in Blender at the Blender BOF, Monday August 11, ~3-4 PM, Convention Center room 501A
  • Some physics enthousiasts will gather on Wednesday after the Jiggly Fluids session (at the exit door), around 6.30PM.

Hope to meet you there,