Various improvements related to height queries against an ellipsoid #1000
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EllipsoidTilesetLoader can conceptually create tiles of any level. But because we use a uint32_t for the tile X and Y coordinates, and because tile level 31 has 2*2^31=2^32 tiles, we end up overflowing the uint32_t and producing nonsense tile coordinates. So this change prevents the loader from creating tiles past level 30.
EllipsoidTilesetLoader was passing a size to the constructor for the std::vector used to store the indices, and then it was also adding the indices by calling `insert`. That resulted in a giant block of useless (0,0,0) indices, followed by the useful ones created by the insert. This change uses `reserve` instead of passing a size to the constructor.
IntersectionTests::rayTriangleParametric was returning "no intersection" when `det < Math::Epsilon6`. This was causing it to miss intersections in very small tiles. So I changed it to `Epsilon8`.
The min and max properties of a glTF accessor are optional. But `intersectRayScenePrimitive` in `GltfUtilities` was assuming the primitive's position accessor had them, and it would crash if they did not.
kring
changed the title
j9liu
reviewed
Nov 20, 2024
Cesium3DTilesSelection/include/Cesium3DTilesSelection/TilesetContentLoader.h
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Thanks @kring ! Just tried this out in Unity and confirmed that sampling ellipsoid heights no longer causes a crash. Merging! |
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EllipsoidTilesetLoadercreate tiles past level 30, because the integers used for ourQuadtreeTileIDwill overflow at level 31.IntersectionTests::rayTriangleParametric, allowing it to find intersections with smaller triangles (such as the ones generated byEllipsoidTilesetLoaderfor a level 30 tile).GltfUtilities::intersectRayGltfModelto crash when the model contains a primitive whose position accessor does not have min/max values (such as the ones created byEllipsoidTilesetLoader).ITilesetHeightQueryinterface. It may be optionally implemented by aTilesetContentLoaderin order to provide a more efficient way to query heights. For example,EllipsoidTilesetLoadersimply returns 0.0. Or, a tileset that has a corresponding web service to query heights could use that, instead of downloading and sampling tiles.Fixes #994