The point that stays stationary during a resize/rotate:
"anchor" (default) — the clip's position point. The only mode that never implicitly writes
position: a session op with "anchor" changes exactly the properties it names.
"center" — the geometry-box center (its true world location under rotation).
"opposite" — resize only: the edge/corner opposite the dragged handle.
[x, y] — an arbitrary composition-space point (escape hatch for custom host pivots).
Semantic values are resolved ONCE, from the session's captured initial bounding info — not
re-resolved per call — so repeated calls with the same inputs are idempotent (no positional creep
through a moving center).
The point that stays stationary during a resize/rotate:
"anchor"(default) — the clip'spositionpoint. The only mode that never implicitly writes position: a session op with"anchor"changes exactly the properties it names."center"— the geometry-box center (its true world location under rotation)."opposite"— resize only: the edge/corner opposite the dragged handle.[x, y]— an arbitrary composition-space point (escape hatch for custom host pivots).Semantic values are resolved ONCE, from the session's captured initial bounding info — not re-resolved per call — so repeated calls with the same inputs are idempotent (no positional creep through a moving center).