Transform

I check the example.TransformPipeline And I found that the forearm rotate around the center of the scene. How to rotate the forearm around the connection point between arm and forearm

Any tips?

You can try to translate the data, rotate and translate back.
Alternatively, you can set the transformation matrix of rotation around and arbitrary point directly.

check the API for vtkTranform here it allows you to follow either approach.

thanks