Two independent, silent breaks made an H3 i2v scene generate from the prompt
alone.
1. The Editor always runs split_by_transitions, and the per-scene conditionings
REPLACE the single entry Studio built — but they were re-encoded with no
reference_image and no h3_references. Both the frame-0 keyframe pin and the
Qwen vision presentation were gone before the sampler looked, even for a
one-scene project. The split now carries the anchor onto scene 0 and the
references onto every scene. Gated to H3: on LTX the anchor rides in the
latent, and adding Gemma3 vision to scene 0 would change existing output.
2. A MiniMax H3 Image to Video node hands its first/last frame pins out on its
CONDITIONING output, which had nowhere to go — the sampler's positive comes
from Studio. New optional h3_keyframes input on the Chain Sampler salvages
them: first frame onto the opening scene, last frame re-indexed onto the
closing scene's own final frame (the source node's frame_count is its own,
and a stale index would land mid-clip where PackedLayout refuses it). The
editor auto-wires it for H3 projects.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
