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I can't seem to find any info on connected rigid bodies by a joint. Can someone explain the basics to me? I'm trying to do a little research to find out how feasible it would be to implement 3d ragdoll physics for my first person shooter game.

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That would seem to be a situation that cries out for being handled in Lagrangian mechanics (because you can define most of your generalized coordinates to be the joint angles). See any upper division or graduate mechanics text. – dmckee Mar 17 '11 at 1:57
you may also be interested in the question Resources to learn programming rigid body simulation over at gamedev.SE – Tobias Kienzler Mar 17 '11 at 12:40

A rag-doll is mostly connected with ball joints, which constrain the position of one point of the rigid body, and allow all three degrees of freedom. There are no easy answers, although the equations needed can be found in college level dynamics book.

Here is a reference that explains the science of rigid bodies.

Then again searching for manikin simulation yields a lot of hits, with some game related ones.

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Probably too late for the OP, but for the sake of the next generations or anyone searching about something related to this topic, I'm dropping this link:

This article actually contains everything you need to know about programming cool ragdoll physics engine. Code samples included!

This article is actually one of the turning points in my life, will it be yours as well? :)

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I get a broken link. – ja72 Jul 19 '12 at 14:32
Sorry, I should've included the article name. It's "Advanced character physics" by Thomas Jakobsen. It's pretty well googlable. – airguru Oct 17 '12 at 14:31

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