DrftAsset

Separate from meshes because they are not parts of the model: each one is the model, at a resolution that arrives sooner. A consumer reading a whole file at once has no use for them and ignores them; the streaming loader draws the best one it has until the real geometry is complete. See DrftLoader and docs/FORMAT.md §4.6.

Handed over unparsed on purpose. A level is a whole model, and a consumer that picks one by distance wants exactly one of them — parsing all four to hand back three that will not be drawn is work nobody asked for. Pass the one you want to readDrft again.

Assembled rather than handed over as blocks, because a caller reading a whole file at once has no use for the split: it exists so a stream can put a sparse capture on screen early, and DrftStream.onSplats is where that matters. The records still arrive in the file's coarse-first order, so a consumer that draws a prefix of them draws a sparse whole.

Each says which MATL entry it belongs to. A reader that does not know this chunk skips it by its length and loses only the material it could not have decoded, which is what keeps the format's freeze intact.

null rather than an empty mesh, because nobody built one and there is nowhere to walk are different facts, and a consumer that cannot tell them apart cannot decide whether to build one itself.

Empty means what it always meant — one mesh at the origin — so a caller written before 1.6 behaves identically against a file with a hierarchy it ignores.

The SUBS chunk, added at 1.8. Hand these to installChemistry().match — which matches exactly and reports what it could not, rather than guessing.

The SDFV chunk, added at 1.13. Views over the fetched buffer, so a file that carries fields for geometry a consumer never traces through costs one view apiece and no copy. Hand them to composeGlobalField, which is what turns per-object fields into a world around the camera.

The NNET chunk, added at 1.14. Weights are views over the fetched buffer, in the precision they were written in — half-precision bits stay bits, because the device uploads them as such.

The NGRF chunk, added at 1.15. Tensors are views over the fetched buffer where its alignment allows, in the precision they were written in. @driftengine/texture validates one before it runs, naming any operator it lacks.

Views over the fetched buffer, xyz-packed, in the asset's own space. Turning them into shapes is one line and belongs to whoever has a physics package:

const shapes = asset.colliders.map((points) => hullShape(points));