[vtkusers] get visible surface

[David E DeMarle]

Use vtkHardwareSelector, it is a more recent implementation of visible
surface selection. It will give you cells if you ask it to for
instance. See: http://www.vtk.org/doc/nightly/html/classvtkHardwareSelector.html

I think the only thing that can be done about not needing a monitor is
to use an offscreen rendering context (osmesa for example). Screen
space operations like visible surface selection get too much from the
infrastructure that VTK's display pipeline (and openGL underneath)
provide to make removing them practical.

David E DeMarle
Kitware, Inc.
R&D Engineer
21 Corporate Drive
Clifton Park, NY 12065-8662
Phone: 518-881-4909


On Tue, Aug 21, 2012 at 7:51 AM, Lodron, Gerald
<Gerald.Lodron at joanneum.at> wrote:
> Hi
>
> I have a surface (vtkPolyData) and camera coordinates.
>
>  I do not want to visualize the scene, I only want to get the current visible triangle as a second vtkPolyData object. I found vtkSelectVisiblePoints but it has two problems:
> - it needs a vtkRenderer which needs a vtkRendererWindow, so I always need to display something on real monitor
> - it only returns points, I also want surface cells, especially triangles / polygons
>
> Any hints or do I need to reimplement the stuff? Is there also a raycast opportunity?
>
> Best regards
>
> Gerald
>
> _______________________________________________
> Powered by www.kitware.com
>
> Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html
>
> Please keep messages on-topic and check the VTK FAQ at: http://www.vtk.org/Wiki/VTK_FAQ
>
> Follow this link to subscribe/unsubscribe:
> http://www.vtk.org/mailman/listinfo/vtkusers