[Bug] `TerrainLayer` zooming, `TerrainExtension` draping

[charlieforward9]

Description

TerrainExtension has a few things issues that I'd love to understand piece by piece, but I will keep it simple to start and learn more through discussion with the experts as I isolate the individual issues.

To begin, I need to be able to support super high resolution zooming, eventually, I'd like to be able to support the Google Photorealistic 3D Tiles, but as shown in the codepen, setting maxZoom property to a high zoom leads to fragmenting of the draped layers, hence hiding the details I am attempting to "extend" on the Terrain. (see the close side of the mountain when zooming in)

This does not happen when I restrict the maxZoom to a lover value (ex. 14). However, the drawn texture doesn't update and I cannot accept that as a workaround for the application.

Flavors

• Script tag
• React
• Python/Jupyter notebook
• MapboxOverlay
• GoogleMapsOverlay
• CARTO
• ArcGIS

Expected Behavior

TerrainExtension to work harmoniously across all zoom levels with PathLayer (including TripsLayer)

Steps to Reproduce

https://codepen.io/charlieforward9/pen/dPGjPjY

Environment

• Framework version: deck.gl@8.9.0 (codepen), deck.gl@9.1.11 (repo)
• Browser: Chrome
• OS: MacOS Tahoe

Logs

A glorious discussion about hubble.gl, noodles.gl and nebula.gl with @akre54 ultimately led him to recommending a hand from @felixpalmer on this Terrain specific task.

Thank you all!

[akre54]

It seems to be an issue with 3d tiles at high zoom / high lod.

You might be able to use the polygonOffset prop (see docs) and multiply your layerIndex by some value. You could try switching to offset mode and just using altitude, but if you want that drape texture behavior you'll need to work around the limitations. Maybe you want to use raycasting. Lastly, you can try switching the layer order, which affects the draw order. Something like this may or may not be impacted by the z-buffer.

[charlieforward9]

You might be able to use the polygonOffset prop (see docs) and multiply your layerIndex by some value.

Updated the codepen with my attempt, no change.

You could try switching to offset mode and just using altitude

This wont work for my use case

Maybe you want to use raycasting.

I am not familiar with this strategy, would be happy to dig in deeper once I have itemized and managed all of my other issues with Terrain, Globe and deck rendering.

Lastly, you can try switching the layer order, which affects the draw order.

All else the same, switching layer order hides the PathLayer altogether.

Thanks for all the feedback Adam