[Feat] geojson onto 3D terrain

[cyyyyyyyyy]

Target Use Case

I want to i using geojson/vector tile layer overlayed on generated 3D terrain.

Proposal

[laijackylai]

Are there anyways to implement this with the current tool sets?

[cyyyyyyyyy]

Are there anyways to implement this with the current tool sets?

yes, using mapbox

[laijackylai]

yes, using mapbox

Any examples for that, cuz I can't seem to find an example for it.
Or it will just "work" when you add a geojson layer on top of the terrain layer.

[kylebarron]

I don't believe there's any support for this currently in deck.gl. As I understand it, a GPU-based solution would be pretty involved.

As an aside, you may be interested in a CPU-based solution for vector tiles and terrain tiles that I attempted a couple years ago.

[cyyyyyyyyy]

yes, using mapbox

Any examples for that, cuz I can't seem to find an example for it. Or it will just "work" when you add a geojson layer on top of the terrain layer.

sorry , what I want to express is using the mapbox-gl framework

[laijackylai]

I don't believe there's any support for this currently in deck.gl. As I understand it, a GPU-based solution would be pretty involved.

As an aside, you may be interested in a CPU-based solution for vector tiles and terrain tiles that I attempted a couple years ago.

Thank you @kylebarron, I'll give your library a go. Thanks a lot

[laijackylai]

As I understand it, a GPU-based solution would be pretty involved.

As for a GPU-based solution, is it that we have to temper with the underlying WebGL code when generating the triangular mesh? Or use the generated mesh as input for getting the z-value of the vector features that will be rendered as a new layer?

[kylebarron]

As for a GPU-based solution, is it that we have to temper with the underlying WebGL code when generating the triangular mesh?

For generating the triangular mesh, that shouldn't need any changes. That's already done on the CPU via loaders.gl/terrain or on the backend and sent to the client.

Or use the generated mesh as input for getting the z-value of the vector features that will be rendered as a new layer?

Yeah I think this is the harder problem. For one, for every vertex you need to find a z position, but additionally you need to interpolate between points along the terrain. For example if you have a long linestring, in order for it not to be underneath or over terrain, you'd need to create more points along the linestring for every edge of the TIN. At least this is what I tried to do in that library on CPU. Maybe there are much more efficient algorithms for GPU, but I'm not familiar with those 😄 .

[laijackylai]

thanks for the explanation. I'll try use your library to implement first 😂

[charlieforward9]

https://deck.gl/docs/api-reference/extensions/terrain-extension slightly less experimental when #10250 & #10251 land