Question about the Implement of occlusion culling

Cesium for Unreal
1

Hi , I have a question about Occlusion Culling.

I know we put the hook with CesiumViewExtension into the UE pipeline.
And we create some BoundingVolumeComponents with the same bounding volume of the tile.
and we can the get the occlusion culling results of these boundingVolumeComponents in the function PostRenderViewFamily_RenderThread.

My questions why using the BoundingVolumeComponent? Since we have queryed all the occlusion results in the views , in which I thought there 're the occlusion reuslts of tiles.
We can record the id of GlfPrimitiveComponent corresponding to the tile?

Thanks a lot!

Sincerely,
Qc

2

Hi @chufall,

I apologize for the delayed response. I’m not entirely sure what you mean by your questions – could you explain further what you mean?

From what I understand, occlusion culling in 3D Tiles is implemented in the tile loading and selection phase, before they are even converted into meshes to draw.

The algorithm looks at the bounding volumes of each tile’s content. If the bounding volume of one tile’s content completely occludes a volume behind it, then that occluded tile is not selected for loading / rendering in Unreal.

But perhaps you already knew all this, and I’ve misunderstood your question. :smile: So please let me know!