Expose preview enums as configurable properties.

[PeterSHollander]

Exposes realtime lightfield preview options as overlappable and configurable properties for improved realtime rendering performance options.

I keep my LKG Portrait angled on my desk, so when working I am looking at the right-most perspectives. This made the default restricted viewcone preview (which was centred) inconvenient for my setup, so I figured I'd expose the settings to customize it in the UI! This lets users configure the parameters for skipped-view and restricted viewcone previews, and select multiple different lightfield preview optimisations at once.

Exploring various combinations of these properties, it would appear that the low-res preview is almost required for snappy realtime performance on my system, and then adding either or both skipped-view or restricted viewcone rendering gives greater overhead. It's worth mentioning that I was unable to get the starting cube to render performantly (1 FPS at best) using only skipped-view and/or restricted viewcone rendering (GTX 970, Ryzen 5 3600, LKG Portrait) - even with the viewcone coverage set to 0%, which yielded blank for all perspectives and good recorded debug timings (5ms), but still poor responsiveness and multiple-second delays. This behaviour is at parity with the previous implementation. Adding low-res rendering to the mix made it instantly responsive (>30 FPS). So food for thought that even with fully blanked frames there's something outside of graphics rendering that's bogging down the pipeline, if this isn't known already.

As this is my first pull request, please let me know if you need any additional information :)

[regcs]

Thank you for the pull request. I like the idea of making the restricted viewcone shiftable. However, I am always trying to keep the UI options at a minimum so that (especially new users) don't get overwhelmed by a multitude of controls. I already had a discussion with another users and mad some plans on how to optimize the UI of the live view to allow for more combinations of liveview render modes:

[Lightfield Viewport] Rework the UI for the live view settings enhancement

It would be good, if you would modify your pull request so that it reflects the UI from this discussion. For the new controls you implemented, I would suggest the following:

1. Skipped views: I think there is no need for a slider, if there are only 2 or 3 options. Therefore, I would stick with the dropdown.
2. Restricted viewcone: I think the sliders here are fine, but I would not show them all the time. It would be better, if they would be displayed only when the user has this mode activated.

It's worth mentioning that I was unable to get the starting cube to render performantly (1 FPS at best) using only skipped-view and/or restricted viewcone rendering (GTX 970, Ryzen 5 3600, LKG Portrait) - even with the viewcone coverage set to 0%, which yielded blank for all perspectives and good recorded debug timings (5ms), but still poor responsiveness and multiple-second delays.

That is strange. You should at least get 6 to 10 fps for the default cube scene. Could you please open a bug report issue for that, reproduce the problem in Blender, and post the alice-lg.log and pylightio.log there? Then, we can have a look into this specific issue.

[PeterSHollander]

Sure, thank you for the feedback! I'll play around with those tweaks and submit the bug request 🙂