Theory behind Bullet's raycast vehicle and soft bodies

[xissburg]

I want to know more about how the Bullet's raycast vehicle and soft bodies work, the theory behind them. Any articles?

Thanks.

[fishboy82]

Soft Body is based on Jacobsen's paper. Also a good reference is Muller's "Position based dynamic".
For ray_cast vehicle
see:
http://www.gamedev.net/community/forums ... 1&#2871179

[Erwin Coumans]

Indeed, as fishboy82 mentions some parts of the rope,cloth and soft body are based onAdvanced Character Physics by Thomas Jakobsen. But it is not a single algorithm, but a collection of algorithms and options for simulation and collision detection: the simulation can be velocity based, position based or mixed, and there is the option for shape matching. For collision detection, there is the "collision clusters" option, colliding with deforming convex hull of simplices (vertex, edge, triangle or tetrahedron). It uses a dynamic AABB tree, that incrementally rebuilds itself, as acceleration structure.

If you want to learn more about ray cast vehicles, you could download the free Havok SDK and check their extensive documentation on this topic.
Thanks,
Erwin

[xissburg]

Thank you both for the information.

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