WanAnimatePlus SCAIL_2 TwoPhase Settings

If you've tried to generate a long SCAIL-2 clip on the wrapper side - the WANVIDIMAGE_EMBEDS chain, not the official Flow chain - you've met the drift problem. The model's native context is 81 frames, so anything longer is chunked, and each new chunk starts by re-denoising the tail of the previous one. That re-denoise is where the handoff area turns to mush and identity starts wandering. This node is the targeted fix: three numbers that tell the sampler to freeze (or lightly denoise) the front of each chunk so the handoff survives.

It's a thin, honest node. One input in - image_embeds in the wrapper's WANVIDIMAGE_EMBEDS type - three settings, one output out, and it just stamps the settings into the embeds dict it passes along. No VAE, no images, no geometry. If that sounds like a passing-through settings node, it is. What matters is what it adds.

The three knobs

• phase1_mask (default 0.5) - protection strength for the first phase of sampling. 1=freeze/protect, 0=free denoise, per the author's own tooltips.
• phase2_mask (default 1.0) - protection strength for phase 2. The default of 1 means "fully protect," i.e. hold the handoff frames through the second phase.
• phase2_start_step (default 0) - the chunk-local step where phase 2 begins. Set to 0 and two-phase sampling is disabled entirely, so the whole chunk runs as one phase.

The mental model: your chunk gets sampled in two regimes, and these masks control how much of the front of each chunk is pinned to the previous segment's output versus allowed to denoise freely. Start with the defaults, then nudge phase1_mask down if the handoff looks frozen/blocky, or up if it's drifting.

Where it sits

If you're on the Flow nodes, you don't need this - the Flow Sampler exposes phase1_mask, phase2_mask, and phase2_start_step directly. This node is for the legacy wrapper chain: drop it between WanAnimatePlus SCAIL_2 Embeds and the sampler, and the sampler picks up the settings from the embeds object.

One warning the README-level docs make plain: the two-phase settings only affect the internal loop's handoff chunks. If your model already carries a context handler, the official context path takes over and these numbers stop forcing anything - you'll see it logged.

Install

Part of the ComfyUI-WanAnimatePlus pack, so the usual routine:

cd ComfyUI/custom_nodes
git clone https://github.com/wuwukaka/ComfyUI-WanAnimatePlus.git

Restart ComfyUI (or grab it via Manager by searching "ComfyUI-WanAnimatePlus"), keep the original ComfyUI-WanVideoWrapper installed, and don't mix node families in one workflow.

Honest verdict: this is a utility node, not a headline feature - 300 words of settings that only matter once you're pushing past 81 frames and hitting the chunk handoff. But if you're chasing long SCAIL-2 takes, it's exactly the kind of small, specific tool that saves you a weekend of babysitting a sampler.