Mechanism behind prioritization of sectors

[Veronika Solteszova]

Hi,

I am trying to understand how sectors are prioritized and loaded in/out using OrderSectorsByVisibilityCoverage.
Currently, looking at OrderSectorsByVisibilityCoverage::orderSectorsByVisibility -> OrderSectorsByVisibilityCoverage::renderSectors, which creates the priority list of sectors. The rendering of sector ids into a texture target, unpacking and reducing is all clear. However, I think I am not getting how a subset of the sectors are being rendered into the target at all.

I think it boils down to this step and which geometry is exactly rendered in step 2 vs step 3?:

 // 2. Render already loaded geometry to offscreen buffer
 this._alreadyLoadedProvider.renderOccludingGeometry(renderTarget, camera);
 // 3. Render to offscreen buffer
 this._renderer.render(this.scene, camera);

When I dive into step 2, I end in EffectRenderManager::renderDetailedToDepthOnly, where nodes are moved from _originalScene to _cadScene and later restored back to _originalScene.
What is the functionality of _cadScene and _originalScene. How are they different?

In ByVisibilitySectorCuller::update, sectors near to the camera should be put together with the priority list of sectors:
const prioritized = coverageUtil.orderSectorsByVisibility(camera);
The length of the priority list prioritized.length is greater than the number of nodes (SectorNodes with LOD=detailed) that are moved to _cadScene in renderDetailedToDepthOnly.

That means more sectors come in through the _renderer.render(this.scene, camera). Is it possible to explain how? How does _cadScene and _originalScene of the EffectRenderManager compare the scene of the GpuOrderSectorsByVisibilityCoverage ?

Maybe you @larsmoa as it seems that you wrote the code?
Thanks a lot in advance.

-veronika

[Lars Moastuen]

I'm impressed by the details in this question! Answering this in text seems like a daunting task - maybe we can set up a meeting instead? Can you reach out at [e-mail] so we can set up a call?

[Veronika Solteszova]

Perfect, thanks! Wrote you an email.

[Lars Moastuen]

Thank you for the discussion, @vero-so - here's the PR, thank you for the contribution :)

#2127

[Veronika Solteszova]

Thanks to you as well!