Past few days I've been trying to arrange a marriage between my Kinect Algorithms and Box2d and it finally came up very well. As they both didn't really love each other I had to forcefully arrange an Indian style of marriage between them. Box2d accepts only shapes and that too only basic shapes with less than 8 sides. And it is impossible to draw a human shape in that restrictions. So I had to bring up a basic shape filled object in the shape of a human and I had to do it live for every frame. The interaction looked really wonderful and people really enjoyed it.