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Version 2.0.0

The next release of dyn4j is ready! The new version, 2.0.0, features CCD and ray casting.

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Posted on September 09, 2010

Version 1.1.0

A new release is ready with some significant changes, mainly very stable stacking thanks to Box2d’s contact block solver.

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Posted on July 29, 2010

Equality Constraints

After the first release of the dyn4j project, I felt that it would be good to pass along what I learned about constrained dynamics. This is not an easy subject and aside from purchasing books there’s not much information out there about it for those of us not accustomed to reading research papers or theses.

Posted on July 24, 2010

Documentation Update

The latest version (1.0.3) has newly added documentation. Namely references to the open source project Box2d that I meant to have in before the first release. The @since and @version tags were also added so that differences in API versions are documented.

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Posted on July 24, 2010

Point-to-Point Constraint

As the first entry after the Equality Constraints post, we will perform the derivation of the Point-to-Point constraint, which models a Revolute Joint, in 2D.

Posted on July 24, 2010

dyn4j Is Released!

The first release of dyn4j is out!

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Posted on July 10, 2010

Version 0.7.2

It’s been a while and to be honest I haven’t completed much (as far as implementation). However, the current version of the project is now 0.7.2 so at least you can see we are getting closer to release. The latest version contains a number of improvements and two joints. The testbed received a little face lift and the tests have been tweeked for consistency.

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Posted on May 31, 2010

EPA (Expanding Polytope Algorithm)

In the last few posts we learned about using GJK for collision detection, distance between shapes, and finding the closest points. It was stated that GJK must be augmented with another algorithm to find collision information like the penetration depth and vector. One such algorithm is EPA.

Posted on May 14, 2010

GJK, Distance, Closest Points

The last installment talked about the GJK algorithm as it pertains to collision detection. The original algorithm actually is used to obtain the distance and closest points between two convex shapes.

Posted on April 26, 2010

GJK (Gilbert–Johnson–Keerthi)

Today I’m going to talk about the other collision detection algorithm packaged with the dyn4j project. You can find a lot of GJK documentation but much of it is really technical mostly because they are research papers. I strongly recommend this video tutorial and to be honest you may not even need to read any further after watching. But if you feel you need more information after watching the video please read on.

Posted on April 13, 2010