Multishot Advance Project Cache Preview

The whole selling point of Multishot Advance Project is that finished shots are cached as raw reusable state, so you can come back a day later, tweak one prompt, and only re-render what actually changed. That's great until you want to check what a cached shot looks like - because the obvious way is to load the model, run the sampler, and watch it either skip or re-render. Both waste time, and one defeats the point.

This node closes that gap: it plays back completed cached clips straight from the project's cache-v2 artifacts, without sampling, without loading the model, and without VAE decoding. It's a preview-only tool for the cache itself.

How it works

Connect the Project node's output:

Multishot Advance Project.project -> Multishot Advance Project Cache Preview.project

The node walks the project's cache manifest, verifies every artifact it plans to show - file sizes, SHA-256 checksums, sampler identity, and schema - and only then builds a temporary player copy and encodes it for playback. If an artifact fails verification, it's treated as a cache miss rather than a crash.

Two details are worth understanding. First, prefix_index selects which cache prefix to show; 0 means "the latest prefix compatible with the current project prompts and sampler identity." Second, the node is strictly read-only - it doesn't prune, rewrite, invalidate, or resume anything. It's a window into the cache, not a management tool. If you want to force a fresh render, that's the Project node's rebuild_project mode or the sampler's rebuild_cache.

The inputs and output

The four settings are small and self-explanatory once you know what a "prefix" is:

• project - the Project handle. Required, obviously.
• prefix_index - 0 = latest compatible prefix. Bump it only if you've rendered multiple prefix generations of the same project.
• view_mode - complete_prefix plays every cached clip through the selected prefix; last_clip_only shows just the final one.
• preview_quality - quick caps the temporary copy at 720p; full keeps cached resolution. Neither touches the cache.

Outputs: video_path (the temporary file it made), frame_count, duration, and a report string with the verification details.

Installing it

It ships in the pack, so:

cd ComfyUI/custom_nodes
git clone https://github.com/KursatAs/ComfyUI-H3-Multishot-Advance

Restart ComfyUI. It needs the same things the pack's video save node needs - an ffmpeg binary, which the pack resolves via imageio-ffmpeg first (handy for portable ComfyUI installs) and falls back to ffmpeg on PATH.

Common issues

The most common "issue" is actually good news: nothing to preview. If the project has no compatible cached prefix - because settings changed, the cache is empty, or you're in a state where every shot is dirty - the node has nothing to verify and tells you so via report. You can't preview a shot that hasn't been cached.

Second: it's read-only by design, so people who expect it to also trim or repair the cache get confused. Third, remember this previews cache state, not the final joined master - the seams and joins you'd see in the finished video aren't in the per-shot cache artifacts, so a clip can look fine here and still need the sampler's join logic to look right end-to-end.