“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.”
The 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.
“We use it for our character controller (our own custom one), line of sight checks, and so forth as well as for vehicle physics in the Racing and Demolition Derby instances.”
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.
- For more information, visit:https://www.cmpevents.com/GD09/a.asp?option=C&V=11&SessID=8531
- A preview of the CUDA constraint solver for Bullet can be downloaded here, or watch the Youtube movie if you don’t have an NVidia card with CUDA 2.1 installed.
- UPDATE: here are the slides as Google presentation, or as PDF
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.
- For more information visit http://www.bulletphysics.org/Bullet/phpBB3/viewtopic.php?f=18&t=3177
- Quote from a forum posting: “
Bullet 2.73 has been released, download from http://code.google.com/p/bullet/downloads/list
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.
- Check this forum topic to see what’s new
Thanks to everyone for feedback, bug fixes and improvements!
- Blender 2.48 has been released: http://www.blender.org/development/release-logs/blender-248/
- Maya Dynamica plugin next?
- 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.