threejs-procedural-fields

Procedural Fields

Author one deterministic field bundle, then adapt it to each shader stage and consumer. Coordinates, seed, causes, derivatives, and output meanings belong to the field; fragment footprints, vertex LOD, storage, and diagnostics are consumer adapters.

For multi-system work, $threejs-choose-skills is an optional coordinator. Materials own PBR response, geometry owns topology, water owns free-surface state, and the final-image skill owns tone mapping and output conversion. Publish each cross-system field output with units, coordinate/frame convention, producer and consumer owners, revision, spatial/temporal support and filter, validity domain, error bound, update cadence, and staleness rule. Keep GPU resource layout and render LOD private to the consuming adapter.

1. Freeze the field contract

Record before implementation:

coordinate domain and units
seed owner, hash/noise family, and wrapping convention
primary fields -> derived causes -> named outputs
consumer, filter, precision, update cadence, and validity per output
direct-versus-bake decision inputs
debug view and invalidation key per output

Choose coordinates from the cause: world/tile-local for terrain and weather, undeformed radial physical coordinates for planets, object/local coordinates for ornament, or a declared generated-texture domain. Large domains use an integer tile plus local float (or another split representation) before f32 phase error changes the field.

This step is complete when every output has one coordinate/seed owner, units, consumer, filter, precision, update rule, invalid state, and diagnostic.

2. Author one stage-portable core

Implement the shared causes as a deterministic TSL Fn. Keep the core free of fragment-only derivatives, vertex camera policy, storage layout, and dispatch state. Materialize common intermediates once with .toVar() or an equivalent local; inspect generated WGSL when separate outputs might rebuild the same warp, hash, or octave chain.