[vtkusers] Mixing images with 3D geometry

[Chris Volpe ARA/SED]

This seems like it should be an easy thing to do, but none of the documentation or examples I've seen seem to do what I want. I would like to draw 3D geometry on top of a 2D background image. I want the image to subtend a fixed angular extent, e.g. if the camera FOV is 30deg, and I define the image as 30deg, I want it to fill the vertical extent of the render window (assuming the camera is not set to Use Horizontal View Angle) . I want *all* 3D geometry also in the scene to be drawn on top of the image - i.e. the image shouldn't have a "position" which would allow it to obscure the 3D geometry. When I change the camera pose, I want to provide a new image, but I don't want the image to be viewed at an oblique angle - I want it to be centered facing the camera again. vtkImageActor just maps an image onto a planar surface sitting out in space and doesn't maintain its place and orientation  in the render window. Basically, I want the functionality of vtkFollower, but in addition to automatically correcting its orientation so that it always faces the camera, I want it to automatically correct its position so that it's always in the center of the field of view and always at the right distance. Does this functionality exist anywhere or do I need to jump through some hoops in my render loop to achieve this?

Thanks,

Chris
--
Christopher R. Volpe, Ph.D.                                                           Email: cvolpe at ara.com<mailto:cvolpe at ara.com>
Senior Scientist, Information Exploitation Systems             Main Desk: 919-582-3300
Applied Research Associates, Inc<http://www.ara.com/>                                                     Direct: 919-582-3380
8537 Six Forks Rd., Suite 6000                                                            Fax : 919-582-3301
Raleigh, NC 27615                                         Web: http://www.ara.com/offices/NC.htm


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.vtk.org/pipermail/vtkusers/attachments/20110701/63eeeb13/attachment.htm>