I hope you don't mind if I ask for a bit of advice regarding modelling robotic systems. I've recently become rather interested in using inverse kinematics (IK) to control a 5 dof robotic manipulator. I have a solid foundation in IK but what I'm having trouble with is a way to visualize how the manipulator moves with respect to joint angles. 
I've looked into using 3D toolkits (such as Blender, Panda3D, vPython) to create a 3d model of the arm, but I'm not sure if I should be looking something with physics support. I'm also not sure how well I can model motion with these packages. Anyone have any suggestions? What I'm NOT looking for is a full blown robotic simulator like Microsoft's Robotic Studio, I'd like to start with the basics and learn how everything works first, ie code the IK in Python, then visualize the motion in 3D. I'm very familiar with Python, so something that interfaces with Python would be preferable. 
Thanks!
This isn't really a hard problem, is it?  Presumably you're working out the math on your own; so if your robotic arm is visualized as, say, a few rectangular solids then all you need is something that will render these at the x,y,z coordinates and with the orientation vector you supply, updating when need be.  OpenGL should do just fine for this, you could probably do it in <50 lines.
Modelling a robotic arm motion in 3D, ideas?