With --report the scenario prints, on Navara, the scene, globe and
combined depths at the sample pixel with the drape hidden, shown and
hidden again, the buffer the ground pass classifies it as, and whether a
shown tile lies on the ray, so a drape on the wrong surface explains
itself.
Navara's 3D Tiles source defaults to model.height 1, which moves a
transformed tileset by a metre along Earth-fixed X: on the synthetic set
flat roofs read 0.12 m high and a sloping roof 0.68 m off, and the drawn
meshes move with them. The adapter sets the height to 0 and records the
package behaviour in WORKAROUNDS.md, with a test that loads the real
package. The downward surface ray now takes its direction from the
place's own normal, so it no longer drifts sideways.
qa-tiles-fixture gains --report (heights and drape pixels per engine,
without asserting), starts on Cesium, and checks each drape hidden, shown
and hidden again; qa-surface-heights uses the plan's 0.5 m tolerance under
tiles and names the point that misses.
A generated tileset (a plate at ellipsoid level, 50 m and 200 m blocks and
a pitched roof, 27 KB) replaces Google's tiles when a QA page passes
?qaTileset=/path; only a root-relative path on the page origin is
accepted, and the Google credit is not shown for it. The strict harness
serves the set from disk, so nothing reaches Google.
qa-tiles-fixture checks on both engines that sampleHeight reads the block
at 50 m, clampToHeight lands on the roof, tiles and terrain drapes draw
where they should, tilesLoaded turns true, surface points land on the
roof within their budget, and pick renders per pass stay within it.
German Khokhlov