simtk.org

Sherm,

Just wanted to pass along my appreciation for the Theory Document. Definitely a great reference. I now fully understand the underlying reasons on why all bodies must have joints/constraints and be in a chain or loop to ground. It's not that they would "run away" in the model, you literally need them to provide any sort of "placement" as you discuss above.

Thanks,

Brad

Right! I'm glad you found that helpful -- as you can imagine it has a rather narrow audience so I'm always happy to have a new reader.

Regards,
Sherm