symbol, circle, fill-extrusion *-translate properties do not account for terrain height
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Description
Currently `*-translate` properties are implemented by applying[ the translation to the projection matrix of the tile](https://github.com/mapbox/mapbox-gl-js-internal/blob/72082ca47f0c74aeb9c1610c5e861d0eed386721/src/render/painter.js#L619).
Elevation lookups inside various shaders get the height value per-vertex/per-feature using tile-coordinates, which do not have the translations applied.
This effects `circles`, `fill-extrusions` and `symbols`.
`fill-extrusion-translate` and `fill-extrusion-translate-anchor: "map"` used to move a fill-extrusion off the hill.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start at the linked translation logic in src/render/painter.js around line 619, then trace the elevation lookups used by the circle, fill-extrusion, and symbol shaders. Compare how tile-coordinate heights are obtained with how *-translate is applied. Done means translated circles, fill-extrusions, and symbols remain correctly aligned with terrain, including fill-extrusion-translate with map anchoring.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- typescript
- Domain
- computer-graphics, frontend
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 25/100