Optionalopts: ShadowFeatureOptionsReadonlynameStable identifier used for lookup, signature hashing, and pass-name keying.
When false, the feature is skipped each frame. Toggling triggers a cached-graph invalidation.
Filled in by update each frame; reused by addPasses.
External shadow caster overrides; when null, uses frame.shadowCasters.
Active shadow mode ('cascade' | 'clipmap').
Virtual-shadow-map page pooling (only with mode:'clipmap'). Mutable at runtime.
Cascaded directional shadow map. Writes
frame.shadowMapand stashes the frame's cascades + caster list onframe.extrasfor downstream consumers (e.g. aBlockShadowFeaturechain).