Muse Minimax Refine V2 (Beta-matched)

If you've seen the Muse MiniMax Director's Seed Hunt, the pitch for this node is short: why run four full-resolution passes to find a good seed when you can scout four cheap ones and pay for one expensive finish? Muse Minimax Refine V2 is the "one expensive finish." It's bundled in the same repo as the Director, and it's what you wire the scouted candidates into when you've picked the one that actually followed your prompt.

The important thing to understand is what it is not. Refine isn't an img2img pixel re-sample or a "sharpen the video" pass. It's a genuine latent continuation: it takes the chosen candidate's own Stage-1 latent - the exact noise state where sampling stopped - and picks up that candidate's sigma schedule from there, finishing at a higher resolution with the same learned latent upscaler the Director uses for its own Stage 2. Nothing about the candidate's content changes, only its resolution. That's why it's called "Beta-matched": this V2 node was originally built to pair with a two-stage scouting Director, got accidentally deleted, and was recovered and reinstated in this repo precisely because it's the one that matches this Director's two-stage/Seed Hunt mechanism.

The flow

On the Director, run two-stage sampling with Seed Hunt on and Latent-Only Scouting (two_stage_seed_hunt_latent_only) on - that's what makes each scout stop after the cheap Stage 1 and exposes the continuable latent on the candidate_1..4_latent outputs. Wire those four into Refine's matching inputs, then click the candidate button in Refine's own UI.

The inputs that matter beyond that: candidate starts at 0, and the node deliberately refuses to run until you pick one - there's no silent "just use candidate 1." prompt takes the Director's compiled_prompt (ignored for multi-chunk candidates, since each chunk already carries its own saved prompt). Wire ref_images from the Director's ref_images_used output so identity stays anchored - without it, any detail the prompt doesn't spell out is free to drift. Same for ref_audio_1/2/3 from the Director's ref_audio_1_used etc., if the original used voice references. model, first_frame, and last_frame are all optional: leave them unconnected and Refine auto-uses whatever the Director embedded on the chosen candidate. Outputs are plain images and audio, straight into your usual Video Combine node.

For a multi-chunk candidate it gets smarter: Refine detects that the latent carries several chunks, refines each in turn, and re-anchors continuity from the previous chunk's freshly refined output the same way the Director does between its own chunks, so the seam survives the resolution bump. raw_latent_carry_test (on by default) is what hard-freezes each continuation chunk's opening against the previous refined chunk's real latent, rather than the weaker pixel re-encode carry.

Install

Same install as the Director - it's the second node in the same package:

cd ComfyUI/custom_nodes
git clone https://github.com/muse-collective-26/MiniMaxH3-Director-V1.2

...or search Muse Minimax Director in ComfyUI Manager and restart. Because Refine's own two-stage finish uses the same latent upscaler family, it shares the Director's two less-obvious requirements: a latent-upscale checkpoint in ComfyUI/models/latent_upscale_models/, and ComfyUI-H3-Motion-Context-MultiRef for the multi-chunk carry. Model weights come from MiniMaxAI/MiniMax-H3 on Hugging Face - see the Director article for the license caveat, which matters here too.

Where people get burned

Two settings behave like traps until you know the reason. seed, steps, and two_stage_first_pass_steps must match what the chosen candidate's Stage 1 was actually generated with - Refine reconstructs the same sigma schedule to continue exactly where sampling stopped, and a mismatched seed means continuing the wrong noise curve from the wrong place. And if Refine "does nothing" with no popup, you're probably refining a candidate slot that never ran - scout only two candidates and click candidate 3, say, and you get a clean block with a console-only warning. (An older version used ExecutionBlockers for empty slots, which silently stopped Refine from running at all whenever you scouted fewer than four; that's fixed.) Pick the right button and the whole flow - scout cheap, refine once - is the closest thing MiniMax H3 has to a sensible production loop.