Multipart Boundary Collision Motion Study

Create a 12-second reference-led video for coding using [multipart encoder interface], [payload samples] and [boundary policy]. Core visible action: a payload substring passes unchanged while a complete boundary line separates two parts. The intended task is to design fixtures where payload bytes resemble delimiter boundaries; distinguish complete delimiter lines from incidental substrings and specify expected part counts. Use three shots: establish at 0–3 seconds, demonstrate at 3–9 seconds, hold the result at 9–12 seconds. Make the result understandable without sound. Use one consistent set of props; do not add unsupported labels, quantities or transformations.

Confirm required reference images and timing inputs are present before generating. Keep objects, identities, spatial relationships and light direction consistent. Render the clip when video generation is supported; otherwise supply a timed shot list, reference checklist and generation-ready prompt, labeled as a production plan. Do not claim rendered output without an actual file. Check the opening, transition and final frame against the stated counts and geometry.