OSPRay volume rendering not available

[demarle]

Describe the bug

In VisIt develop today (just beyond the VTK 9 bump) OSPRay volume rendering does not seem to be choosable on the Volume plot page like it is in VisIt 3.3.0. OSPRay surface rendering works fine in my build and Allen did demonstrate volume rendering in his branch so I am thinking that it is likely something trivial like not exposing a new name for the GUI widget to show or something like that.

Helpful additional information

• Did VisIt crash: No
• Did you get wrong results: Yes

To Reproduce

Steps to reproduce the behavior. For example:

1. Build develop branch and enable ospray
2. load a .vti file
3. add volume plot and draw
4. PlotAtts->Renderer Options
5. OSPRay is not available as it was in 3.3.0.

Desktop

• Ubuntu 20.04 ish
• VisIt Version: develop e2db1ce9fe53a5688782b01eccfa15f8096220ab

[biagas]

Did you build with VTK 9 or VTK 8 ?

[demarle]

I built with VTK 9, and more specifically the VTK that was constructed via the build_visit script from the visit develop branch.

thanks

[biagas]

Here's what the Volume Plot window looks like when I build develop against VTK 9 and OSPRay 2.8 .

Is your build of VisIt a completely new build? Are you using OSPRay 2.8? It should have been built automatically when vtk9 was chosen during build_visit. Did your host profile get updated to use this version?

[demarle]

Thanks again. The issue I think I see is that in the "Rendering Method" pulldown above I don't see "OSPRay in one of the alternative options to "Serial Rendering". In 3.3.0 there was.

[biagas]

The OSPRay rendering for VTK 9 is now available in the Serial or Parallel method when you enable OSPray for either of those methods. You would have to ask @ARSanderson how they differ from the 'Ray casting: OSPRay' option.

[demarle]

Ah that is right. I do recall that OSPRay volumes are now funelled through the render pass.

However, with "Serial Rendering" selected above, when I enable OSPRay for the whole scene via Options->Rendering->Advanced->"OSPRay Rendering", and apply, the bounding box is OSPRay renderered, but the volume disappears.

Perhaps the bug is that VTK/Rendering/RayTracing/vtkOSPRayViewNodeFactory needs a new visit specific class name.

Alan please do advise, I could be doing something else wrong too of course.

[biagas]

This problem sounds like something Alan noticed, it was happening for him only with certain datasets. He tried to make note of everything and create issue tickets, but I'm not certain that everything made it in yet. VTK 9 support is still considered experimental and definitely not complete at this point in time. Feel free to document any problems you encounter so we don't lose track. Add VTK-9 to the title for easier searching.

[ARSanderson]

OSPRay volume is an option of the serial/parallel rendering. It is no longer a separate rendering type. OSPRay surface rendering is the same as before via the Options->Rendering->Advanced->"OSPRay Rendering."

I notice volumes not being rendered in certain circumstances with the serial rendering. I am not sure I made it an issue.

[cyrush]

resolved in 3.4.1