[ODE] How to Build the Model?

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Hello everyone here,
   i try to use ode as my dynamics engine to the my project.we are majoring in mechanical engineering,when building the simulation model for ode,i have some problems to ask
  1.when build the "mass",i use the function"setparameters(....)",which will be filled the mass quatity,center point of gravity and the inertia tensor. can anybody tell be the center of gravit referencs to the local frame or global frame? and about the inertia tensor?

   2.when build the "body" ,there needs to set the "positon",the question is the same as ahead. Moreover,
is it necessary to set the orientation of the body?

   3.when build the "joint",for example the hingerjoint,
there needs to set the joint anchor and joint axis vector.do these parameter reference to local or global frame?

   4.when using the function of getRotation(),it returns the R, from the forum,i learn that it must be transposed, is it true?

   I have integrated ode into my project( we are using wtk as our rendering tool),but the result of the simulation is wrong.

    can anybody help me?

                  Allen.Wan