using both kinematics and physics element for a single model


I’m working on a rigid-body dynamics simulator which handles articulated systems with loops. The simulator expects
as input a tree of bodies, linked by kinematic joints and some additional constraints for the loops.

I would like the simulator to use collada files as input. However, I’m not sure that I can describe the tree of rigid bodies in collada. If I understand the specification correctly, I would need to use elements from both the physics and the kinematics parts. Is it supported ?

From the following statement (p453), I think it is, but I don’t know how.

The kinematics elements relate as follows to existing capabilities of COLLADA:
• Use the definition of a <node> hierarchy that is independent of any joint declaration
• Allow physics- and kinematics-model instances to reference these nodes
• Use the shapes that are declared for each node for visual representation
• Define the node hierarchy using <library_nodes> (or directly in <visual_scene>)

Can somebody here shed some light on this?

Thanks !


in COLLADA the different contexts (phyics, kinematics, visual representation) are strictly seperated from each other.

The kinematics part describes objects that can move by their own.
The physics part describes objects that are moved by external forces e.g. gravity.

The combining of these different models is done through the scene element while instanciating all the different scenes.

A good example can be found here: … xample.dae