New answers tagged physics-engine
I guess you are using the initial world transformation of the body. you should get the current motionState transformation of the body to get the current position. Also make sure you are not stepping the dynamicworld or you will get the values after applying physics. I am usually using the below trick: Instead of using my_body->getWorldTransform(), try ...
I finally found a very clear derivation, here: https://fgiesen.wordpress.com/2012/08/24/quaternion-differentiation/ It's by Fabian Giesen (ryg) of demo-scene fame.
Top 50 recent answers are included