Project: Lighting problems with latest SlicerVR

[cpinter]

Draft Status

Ready - team will start page creating immediately

Category

VR/AR and Rendering

Key Investigators

• Csaba Pinter (EBATINCA, Spain)
• Andras Lasso (PerkLab, Queen's, Canada)
• Matt Jolley (CHOP, USA)
• Kitware? (Jc / Thibault)

Project Description

There is a regression with how latest SlicerVR lights the scene, both with the old VR and the new XR backend.

• OpenVR: Default lighting looks as expected, but now SSAO and Lights module options are not applied on the VR view (even if the view node IDs are explicitly selected)
• OpenXR: Default lighting looks washed out

Objective

1. Make both backends of SlicerVR work like before the regression
   • "Normal" lighting by default
   • Lights module changes have effect on VR view as well

Approach and Plan

1. Investigate the problem with the help of people directly involved in the OpenXR integration
2. If we find the root cause of either issues, try to address them

Progress and Next Steps

1. Describe specific steps you have actually done.

Illustrations

The following screenshots demonstrate shadows vs no shadows in OpenVR:

Left: Slicer view using OpenVR without shadows
Right: VR view (with back lights / without two sided lighting)

Left: Slicer view using OpenVR with shadows
Right: VR view (with back lights / without two sided lighting)

---

The following screenshots demonstrate different lighting options in OpenXR:

Left: Slicer view using OpenXR without shadows
Right: VR view (with back lights / without two sided lighting)

Left: Slicer view using OpenXR without shadows
Right: VR view (without back lights / without two sided lighting)

Background and References

For those who have access to SlicerHeart internals, this is the link to the issue: https://github.com/JolleyLab/Internal/issues/205#event-14879920416

[mattjolley]

@cpinter and team

Thank you for working on this. Let us know how we can support further testing as above.

@iacovellaj and @sp318 are happy to test on our Vive Pro 2 and Meta Quest Pro.

It would be great if the lighting features in OpenVR (or similar) are implemented in the OpenXR version.

[sjh26]

@cpinter it looks like none of the image urls are working?

[cpinter]

Hm, maybe I can see them because I am a member of that private repo. I thought these ridect links worked anyway. It seems they fixed it. Thanks for letting me know, I'll replace them.

[sjh26]