How is rotation determined for a 3d pdf.
When a 3D model is printed to PDF, the rotation point for the Acrobat tools is determined as follows:
For views where the camera is on — the target point for the camera is the point about which the view will be rotated in Acrobat.
For non-camera views — the pivot point is set to the center of the view, midway between the front and back clipping planes. If the front/back clipping planes are disabled, then the model range is used.