Trials HD (XBox 360) uses Bullet

trials_hd“We are also using a modified version of an open source physics engine called Bullet Physics Library to calculate our physics simulation and collision inside the game. We have in-house optimized it for the Xbox 360 CPU and vector units. Our game engine is designed to be fully multithreaded, and we are simulating physics at the same time we are processing game logic, graphics, sound and particles in other Xbox 360 hardware threads. With extensive optimization, we have achieved a very good balance, with all six CPU hardware threads constantly working under heavy load.”

Bullet ranked third physics library at 10% in Game Developers Magazine survey


0908gd_cover_250x339The August 2009 issue of Game Developers Magazine features an article about game middleware, written by Mark Deloura. They surveyed over 100 senior developers of various development houses, mainly working on PC, PlayStation 3 or XBox 360.

According to the article, developers like having access to the full source code. When purchasing a Havok or PhysX license, some of the core algorithmic implementations, such as the core constraint solver or collision detection internals are not exposed. PhysX is rated number 1 at 26.8%, Havok comes 2nd at 22.7%, Bullet third at 10.3% and Open Dynamics Engine fourth at 4.1%.

You can purchase an electronic version of this issue for $3.95 here.

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.