Support rendering 3d extrusions

[amyleew]

Please add building height styling options for building data in Mapbox GL.

Specifically building data in CartoCSS can be rendered in a 3d look using building-fill, building-fill-opacity, and building-height.

Can we add this functionality to Mapbox GL?

[kkaefer]

dupe of #292

[trallarn]

I know this issue is closed, but I can't find any doc on how to render extrusions. Has this feature really been added?

[kkaefer]

No, this feature hasn't been added yet.

[ghost]

What is the status of development on the 2.5d line extruding? Is it something that I could help with?

[ansis]

implementing this:

the first part

• merge the earcut branch Switch to tesselated fill rendering with earcut #1606
• roughly recreate the really old demo branch (example) on top of master. Manually rewriting everything with the old branch as a guide is probably better than trying to rebase.
• figure out how this should look in the style spec. Discuss and implement that
• add render tests
• port to -native

followup

• fix antialiasing (draw faded 1px lines along all edges?)
• fix depth related bugs

[lbud]

I've roughly recreated last year's demo branch at https://github.com/mapbox/mapbox-gl-js/tree/building-redux (thanks to the codespirit of @ansis 👻 the old branch ported pretty easily).

Shaders at https://github.com/mapbox/mapbox-gl-shaders/tree/js-buildings, a spec branch (filled in only by copying fill properties for validation purposes, not definitive spec suggestions) at https://github.com/mapbox/mapbox-gl-style-spec/tree/buildings. I've modified this repo's debug page/style in this branch for the sake of quick iteration, not to be merged.

Still lots of TODOs to clean up rough edges in this branch + will open a spec ticket to discuss what this should look like.

[ghost]

Nice work with the development!

I wanted to get a sense of how far along the development progress is - how long do you expect until functionality analogous to http://keks.com/dev/line3/ will be present.

[lbud]

@jonathanward at this time this feature is still very much in development, and spec changes are still not finalized at mapbox/mapbox-gl-style-spec#456, so I really can't give a timeline — though it is looking like at least initially we don't plan to support extruding non-polygon features.

[lbud]

quick status update:

• most of the spec changes proposed for extrusions are implemented in mapbox-gl-js; mostly finished with adding data-driven properties and then need to figure out antialiasing
• after that, still need to
  • port to native
  • work with Studio team to integrate extrusion type
  • solidify spec changes and do releases of -js, -native and -spec

[yocontra]

@iBud Any docs for enabling this feature? Didn't see any in the PR. Demos look great BTW - thanks a lot for putting in the work!

[lbud]

@contra check out the accompanying style spec PR mapbox/mapbox-gl-style-spec#495 — the fill-extrude-base and fill-extrude-height paint properties enable this, so a fill layer for buildings might include a property function like

"paint": {
    "fill-extrude-height": {
        "stops": [[0, 0], [1000, 1000]],
        "property": "height"
    }
}

if the specified source layer has a property called "height" in its features.
This feature will be in the next Mapbox GL JS library release.