2013-08-18

Good bye ODE, hello GEAR!

I eventually grew tired of ODE's inability to handle cyclic graphs well, and looked for alternatives. Apparently cyclic dependencies in the constraints is a difficult problem to solve so very few solutions exist that will work. Luckily I found an alternative called GEAR (Geometric Engine for Articulated Rigid-body simulation) which was made with cyclic graphs in mind. GEAR is an implementation of a a novelty algorithm using some fancy new stuff called "lie group formulation for articulated rigid body dynamics". The code speaks for itself. Mr. Jinwook Kim who made the original, and Mr. Junggon Kim who adapted it to his use (and from what I can see, extended/simplified the code a bit) really know what they were up to. It seems to use more is nearer to use some basic C++ features and lacks the silly "C <--> C++ <--> C" wrapping of the ODE API. There seems to be no documentation what-so-ever, except for the extremely math-intensive and otherwise dense paper, and code comments are sparse. But the demos are stunning! Please check out the videos on this page.

"Sloop" demo of GEAR
I will make my best effort to use this code in my project, and if I am lucky, it will perform under my demands. One hurdle that I will have to get around is the lack of collision detection and handling, however there is some code for that on the video page that I might be able to adapt.

UPDATE: gear was moved to github.

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