[vtkusers] Mixing images with 3D geometry

[David Gobbi]

Hi Chris,

The way to do this is with vtkActor2D and vtkImageMapper.  Since
vtkImageMapper uses display coordinates, you will have to resample
the image to the correct size and repositiion the actor every time the
window size changes.

 - David

On Fri, Jul 1, 2011 at 7:27 AM, Chris Volpe ARA/SED <cvolpe at ara.com> wrote:
> 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
>
> Senior Scientist, Information Exploitation Systems             Main Desk:
> 919-582-3300
>
> Applied Research Associates,
> Inc                                                     Direct: 919-582-3380
>
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