[vtkusers] How to Set Rotation Center?

[Ted Christiansen]

Hello,

How can I set the center of rotation for a collection of actors?

Tried this and it didnt work as expected:

1.  Use vtkPointPicker to get the point the user picked
2.  Set this to the FocalPoint

It should center the model to this point and then all rotations via the
interactor are about this point.  What am I missing?

Ted


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void CFEvisGLView::SetViewCenter(CPoint point)
{
 CRect viewdims;

 // need to do a pick instead
 // double coords[3];
 double focalpoint[3];
 DoPointPick(point, focalpoint);

 vtkCamera *pCam = Renderer->GetActiveCamera();

 // get view dimensions
 GetClientRect(&viewdims);

 // now we can actually modify the camera
 pCam->SetFocalPoint(focalpoint[0], focalpoint[1], focalpoint[2]);
 pCam->OrthogonalizeViewUp();

 // reset state
 m_state = STATE_NONE;

 Invalidate(FALSE);
}





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void CFEvisGLView::DoPointPick(CPoint point, double *coords)
{
 vtkPointPicker  *pointpicker;
 vtkPoints   *pickedpoints;
 vtkDataSet   *dataset;
 vtkActorCollection *actors;

 // create new point picker
 pointpicker = vtkPointPicker::New();

 // do pick operation (z=0)
 pointpicker->Pick(point.x, point.y, 0, Renderer);

 // get list of actors intersected
 actors = pointpicker->GetActors();
 // get list of points intersected (in same order as actors)
 pickedpoints = pointpicker->GetPickedPositions();

 // get id of point that was picked
 if (pointpicker->GetPointId() != -1) {
  // float fl[3];
  pickedpoints->GetPoint(0, coords);
  TRACE("%f %f %f\n", coords[0], coords[1], coords[2]);
  dataset = pointpicker->GetDataSet();
  if (dataset != NULL) {
   // loop through actors, and find the matching component
   // get value here using point id
  }
 }
}