Custom Mesh File (.bin)

Binary files are the game industry standard format for streaming data from disk to memory at engine run-time  because they can be easily interpreted.

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Bounce Lite Update

I’ve added two joint types to Bounce Lite. Ball-in-socket, and revolute with angle limits. Bounce Lite is available at its repository: here. There is a video below showing how five revolute joints can be used to simulate a small ragdoll.

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MATLAB R2015a Experiences

I look forward to get a MATLAB license after using the R2015a trial for a week. Scalar and vector functions, gradient fields, and level curves are very easy to be evaluated in my experience. Example:

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Reducing Reduntant Render State Changes from DirectX 11.0

I’ve been experiencing frame rate drops when rendering different meshes using my DirectX 11.0 based framework to debug physics and create testbeds. My GPU is a (very-old but still working) NVIDIA 8400 GS 512 MiB of VRAM, so I’ve noted that the problem was brute-force setting a bunch of render states before issuing a draw call.

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Mouse Constraint Derivation

You can read here how to compute the mouse constraint Jacobian, which I think is the simplest constraint along with a distance constraint. It can be helpfull when you’re selecting geometries in the scene using the mouse world space position (as a joint anchor point), since there is lack of controlability by directly applying forces at a particular point of a rigid body shape.

Errata: There is a minus sign before the stabilization term. It should be:

Lambda = (J * M * J^T)-1 * (-J * V – Beta / TimeStep * C)

Note: You can bound excessive impulses to avoid excessive velocity changes.

Thanks to Dirk Gregorius of Valve for pointing those things out via e-mail.

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Bounce Lite Release

I’m happy for distributing Bounce Lite, a portable 3D physics engine for games:

Bounce Lite is available at its GitHub repository. It is the second physics engine that I (Irlan) have written and the first that is publically distributed.

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Vectors and Points

I gave a simplistic talk last week at university for a couple of math and engineering students about vectors and points. You can download the slides translated to the English language here.