Number of tiles, or points budget

[ltphy]

I have tested potree library, which is also a 3d visualization library. There is an option called point budget in that library, which will only render number of nodes depending on the allowed numbers of points and all of the leave nodes will be removed accordingly.

Is there any function in tileset-3d that can execute similarly?
If the function is currently not available, what should I implement in the code to have that similar feature?

[ibgreen]

This seems to be a good feature to handle improperly tiled datasets (the whole point of tiling datasets is to make sure that only a reasonable amount of geometry is selected for rendering at any time).

I think this could be done fairly independently as a post processing pass after the current traversal algorithm (Tileset3D.update) where we would walk the selected tiles top down and remove child tiles when budget is exceeded.

The main wrinkle is that we support multiviewport traversal, so the post processing should be done on each viewport.

If we implement in loaders, we should handle both the point cloud and mesh cases - it should not be much of a difference.

I suppose the post processing could go in here https://github.com/visgl/loaders.gl/blob/master/modules/tiles/src/tileset/tileset-3d.ts#L435

@belom88 thougths?

[ibgreen]

Perhaps we could offer a Tileset3D callback to let the user implement/experiment with tile filtering. Something like
Tileset3D.options.onTraversalComplete(...)

[belom88]

I agree. Let me do this thing.

[ltphy]

One more thing, after filtering out the selected tiles, I have to delete the remaining tiles to prevent the cacheMap to access those that are end of their lifecycle as well.

[ibgreen]

Assuming this is the cache in the deck.gl layer: if the Tile3DLayer doesn't see the tile (assuming filtering in onTraversalComplete prevents the tiles from being returned from tileset.update etc), they should not end up in the layer's cache.

[belom88]

#1596