<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div><span>Two suggestions come to my mind:<br></span></div><div><span><br></span></div><div><span>1 - What about doing the same in VTK as you would in OpenGL?</span></div><div><br><span></span></div><div><span>2 - Setting the focal point of the vtkCamera, perhaps also requires to set the location of the camera.</span></div><div><br><span></span></div><div><span>Maarten</span></div><div><br></div><div style="font-family: times new roman, new york, times, serif; font-size: 12pt;"><div style="font-family: times new roman, new york, times, serif; font-size: 12pt;"><font face="Arial" size="2"><hr size="1"><b><span style="font-weight:bold;">From:</span></b> Wayne Christopher <wayne@4raccoons.com><br><b><span style="font-weight: bold;">To:</span></b> vtkusers <vtkusers@vtk.org><br><b><span style="font-weight:
bold;">Sent:</span></b> Monday, September 12, 2011 10:05:19 AM<br><b><span style="font-weight: bold;">Subject:</span></b> [vtkusers] Setting the center of rotation<br></font><br>I have seen this question asked a few times with no solutions - if it's not possible to do, could somebody confirm this? Do I need to write my own interactor?<br><br>I am using a trackball interactor to manipulate a scene with a number of actors. I zoom in to one area of one actor, and when I rotate the scene, I want the center of rotation to be a point that I can select on the visible actor - that is, not the center of the entire scene, which would cause what I'm looking at to move out of the screen. How can I do that?<br><br>Setting the focal point of the camera causes the scene to pan and move this point to the center of the screen, which is not what I want. Also after panning with the middle button, the center of rotation does not stay where it was
set.<br><br>If I were doing this in OpenGL I would apply a transform to translate the center point to the origin, then apply rotation and scaling operations, then translate the origin back to the center point.<br><br>Thanks,<br><br> Wayne<br>_______________________________________________<br>Powered by www.kitware.com<br><br>Visit other Kitware open-source projects at <a href="http://www.kitware.com/opensource/opensource.html" target="_blank">http://www.kitware.com/opensource/opensource.html</a><br><br>Please keep messages on-topic and check the VTK FAQ at: <a href="http://www.vtk.org/Wiki/VTK_FAQ" target="_blank">http://www.vtk.org/Wiki/VTK_FAQ</a><br><br>Follow this link to subscribe/unsubscribe:<br><a href="http://www.vtk.org/mailman/listinfo/vtkusers" target="_blank">http://www.vtk.org/mailman/listinfo/vtkusers</a><br><br><br></div></div></div></body></html>