OptionalbaseOptionalextrudeExtrude each polygon to this absolute height (m above ground) → vertical walls + a roof cap. A number, or a per-feature function; undefined / ≤ base means a flat fill.
OptionalcolorFill / roof color (linear RGB), constant or per-feature. Default white.
OptionalheightDrape onto streamed terrain: height (m) at a lon/lat, added to baseHeight.
OptionalcollectWhen set, the builder records — for CPU picking — one feature id per emitted vertex
(incrementing per polygon) into ids, and that polygon's properties into props (so
props[id] is the hit feature's bag). ids aligns 1:1 with the result's vertices.
Base height (m above the ground / ellipsoid) of the fill or the wall bottom. Default 0.