I have been trying to use the coordinates of some exported sequences from Slicer to replicate the movements in Blender for demonstration/learning purposes. These sequences have been recorded with slicer using an electromagnetic tracking system.
I have tried both the solution from this post (Exporting Transformations from Sequence in 3D Slicer) and parsing the *.seq.mha files directly, obtaining the same coordinates (so I guess I am looking at the correct data).
However, I have hit a snag trying to replicate the same scene outside Slicer. When importing the models to Blender, I import the sequence by creating a keyframe for each transform that has been exported. Doing it this way, I can’t manage to replicate the same movements in Blender at all. Everything moves erratically, even if the starting positions of the elements coincide between Slicer and the scene in Blender.
It looks like there is some kind of transform hierarchy among the models in Slicer’s scene that is affecting the coordinates (so some of them are relative to other models and not to the “world”, I assume?). Is there any way to check if this is what is happening (I am not an experienced Slicer user) and/or export the coordinates being relative to the world instead to other models? Maybe exporting the models somehow according to how they have been defined in Slicer (pivot points, dependencies, etc.) or something like that.
I have also tried to connect slicer to Unity directly for troubleshooting using OpenIGTLink, and I get the same problem. Can somebody guide me on how to debug this?
Thank you very much.