Switch IGN France to HIGHRES (RGE ALTI) WMS layer#1027
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The previous LAYERS=ELEVATION.ELEVATIONGRIDCOVERAGE is BD ALTI v1, capped at the WMTS z11 pyramid (~25 m EW x 38 m NS at lat 48). The WMS server nearest-neighbour-upsamples that to the requested 512x512 tile, producing 38x25-block flat patches with 2-3 m steps between them in the generated terrain. ELEVATION.ELEVATIONGRIDCOVERAGE.HIGHRES is RGE ALTI MNT served from the z14 pyramid (~3 m EW x 5 m NS), 7-8x finer. Verified at the reporter's bbox: 14 -> 108 source runs per row, plateaus shrink from ~37 px to ~5 px wide. CACHE_NAME bumped to ign_france_hires to invalidate the legacy plateau-quantised tiles on disk; name() is overridden so the user-visible "Selected elevation provider" log stays "ign_france".
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⏱️ Benchmark run finished in 0m 54s 📈 Compared against baseline: 27s time, 935 MB memory 🟢 Generation time is unchanged. 📅 Last benchmark: 2026-05-14 22:57:52 UTC You can retrigger the benchmark by commenting |
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Pull request overview
This PR updates the IGN France elevation provider to request the higher-resolution RGE ALTI MNT WMS layer (HIGHRES) instead of the legacy BD ALTI v1 layer, improving source detail and reducing visible “plateau banding” artifacts in generated terrain.
Changes:
- Switches the WMS
LAYERSparameter toELEVATION.ELEVATIONGRIDCOVERAGE.HIGHRES. - Bumps the on-disk cache namespace (
CACHE_NAME) to invalidate previously cached lower-resolution tiles. - Keeps the user-facing provider id stable by returning
"ign_france"fromElevationProvider::name().
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The previous LAYERS=ELEVATION.ELEVATIONGRIDCOVERAGE is BD ALTI v1, capped at the WMTS z11 pyramid (~25 m EW x 38 m NS at lat 48). The WMS server nearest-neighbour-upsamples that to the requested 512x512 tile, producing 38x25-block flat patches with 2-3 m steps between them in the generated terrain.
ELEVATION.ELEVATIONGRIDCOVERAGE.HIGHRES is RGE ALTI MNT served from the z14 pyramid (~3 m EW x 5 m NS), 7-8x finer. Verified at the reporter's bbox: 14 -> 108 source runs per row, plateaus shrink from ~37 px to ~5 px wide.
CACHE_NAME bumped to ign_france_hires to invalidate the legacy plateau-quantised tiles on disk; name() is overridden so the user-visible "Selected elevation provider" log stays "ign_france".