[kuzehanka]

It'll come down to how frequently you're doing updates. A few times a second will certainly cost more than a prefab mesh with a texture fetch shader.

If you can precompute various LOD chunks for each tile and cache them, under some circumstances that's optimal, but I don't think any of them are webgl. A typical heightmap based terrain renderer today will consist of several (3-5) prefab LOD meshes deformed by height map textures in shader, like[1]. Swapping a textures in and out of vram is cheaper than swapping geometries, even if those geometries are of lower resolution.

Modern GPUs are almost never bound by the number of triangles on screen. The bottleneck will be the fillrate and bandwidth and pipeline stalls, especially in webgl. If you can throw down more triangles to do less of the other things, it's almost always worth it.

I have a toy mapbox tile renderer based on this approach. I'd love to know if you guys have plans to implement full 3d like google maps any time soon.

[1]: https://imgur.com/a/51g2bB4

[mourner]

I would really love to see your toy Mapbox renderer — please share it, even if unpolished! We'd benefit a lot from fresh ideas on how to improve Mapbox GL performance.