support sheared camera projection

[demarle]

VTK users would like OSPRay to support sheared camera projections.

[johguenther]

If I have the right idea what "shared" means, then I think this is supported already, via "imageStart/End" parameters of the camera:

The region of the camera sensor that is rendered to the image can be specified in normalized screen-space coordinates with imageStart (lower left corner) and imageEnd (upper right corner). This can be used, for example, to crop the image, to achieve asymmetrical view frusta...

[demarle]

It appears to be slightly different from that, working to collect more details...

[aylward]

Let me know if you need more info.

[demarle]

original report, with images for more context to help us reproduce https://gitlab.kitware.com/paraview/paraview/-/issues/20467