Rendering 3D Models

[hactar]

Is your feature request related to a problem? Please describe.
Many modern mapping solutions can display 3D models of landmarks such as the Eiffel Tower, or the Statue of Liberty. MapLibreJS offers a solution for this too (https://maplibre.org/maplibre-gl-js/docs/examples/add-3d-model-with-terrain/) MapLibre Native does not. We'd like to be able to add 3D models of a handful of buildings to the map.

Describe the solution you'd like
We're looking for a solution similar to https://maplibre.org/maplibre-gl-js/docs/examples/add-3d-model-with-terrain/, but for MapLibre Native.

Short Term: some form of custom layer that could be added which loads in 3d models and renders them on the map. 3D building extrusions would need to be made compatible with this to ensure that 3d models behind builds are occluded by extrusions.
Long Term: 3D tile support, potentially as part of/compatible with 3D terrain support.

Describe alternatives you've considered
While a hack can be made where one draws 3D models on top of MapLibre Native using a different 3D engine such as SceneKit or RealityKit and then synchronizes offsets and zoom with MapLibre Native, one big problem of this solution would be that building extrusions would always be drawn behind the 3D model, which would cause z-order issues for tilted maps.

Additional context
@sjg-wdw can provide additional technical context from the call we had (thanks again for that 😊)

[louwers]

Related #2725

[sjg-wdw]

I think you described it well!