Bounce Release

The first version of Bounce has been pushed to the following git repository: https://github.com/irlanrobson/bounce. Bounce is a 3D physics engine for games and interactive applications, and hopefully will be a fun project to work on.

Bounce Update

Here is a compilation of a few physics demos using Bounce physics engine. It’s possible to visualize in these demos state-of-the art solutions for rigid body dynamics for games and interactive applications. In particular large block solvers and one-shot persistent contact manifolds. The camera controls are the same as in Maya, and continuous collision is disabled.

Bounce Update

This post is somewhat a description of what I’ve been doing recently. This week I’ve been reading cloth simulation papers to stay a bit away from rigid body dynamics since it is a well solved problem as discussed by the community. Last week I ended up finishing an implementation of contact point clustering using k-means. My experiments have shown that the optimization described in the excelent GPG4 article is available just to show how things got started. However, it can generate good results even if implemented naively, still leaving open doors for more optimization, such as the use of hysteresis to avoid jittering and the like. The video below was one of the first tests that showed some acceptable, still not plausable though, results.

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Distance Constraint Derivation

Sometimes it’s desired to have a distance constraint. That constraint assumes a choosen separation distance for two points fixed in two bodies. I’ve written a derivation for it in 3D and shared here. An implementation should be pretty simple since we have minimally one Jacobian and solve a 1D linear system. Here is an example which you can use in your own projects.

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Fast Segment-AABB Collision Detection

Let’s say we need to compute the intersection point and normal from a line segment to an axis-aligned bounding box (AABB) bounds, and we neither want to perform expensive plane computations nor keep the AABB boundaries as an intersection of 6 axis-aligned planes (as it is a waste of memory). A quick way to do that is by evaluating the slab plane equation for each axis-aligned plane of the AABB.

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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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Bounce Lite Release

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

https://github.com/irlanrobson/Bounce-Lite

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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