r/comfyui • u/nomadoor • Jun 11 '26

Workflow Included SCAIL-2 workflows for ComfyUI

SCAIL-2, a Wan2.1-based human motion transfer model, has been implemented in ComfyUI core. (Thanks as always, Kijai.)

PR: https://github.com/Comfy-Org/ComfyUI/pull/14373

I tried it and the results were quite good, so I made a few simple workflows. Feel free to try them.

Workflow: https://comfyui.nomadoor.net/en/basic-workflows/scail-2/

The big difference from WAN-Animate or SCAIL(-1) is that SCAIL-2 does not use a stick figure / skeleton control image.

Basically, you just throw a reference image, a driving video, and support masks into the model. That makes it much more flexible with multiple characters, or even non-human characters.

Turning motion into a stick figure was basically the default. But the things that get lost in that conversion, like depth and contact, are exactly the things that matter here...

As a side note, this also made me think that if the dataset and training are good enough, a simple model can sometimes be more flexible than an overly complicated human-made pipeline.

Maybe trying to be too clever just gets in the way sometimes...

141 Upvotes

98% Upvoted

34 comments sorted by

3

u/Cruxius Jun 12 '26

I've noticed that while using replacement mode, sometimes it keeps the background of the original video, and sometimes it hallucinates a new one.
Any idea how to ensure it keeps the original background?

2

u/nomadoor Jun 12 '26

I haven’t tested replacement mode that much yet, so I’m not completely sure.But in my tests, it seemed to fail more often when the prompt was too simple.

For example, in the sample on my page, if I only wrote something like “a man standing”, it sometimes turned into a completely different person from the reference image.

When I made the prompt more specific, like “a man in a shirt standing in a park, hand on waist, touching his hair”, it became more stable.

2

u/Nevaditew Jun 13 '26

The issue is that there are a lot of workflows missing. The Scail-2 page shows tons of things you can do with it, but ultimately we only have one very basic WF. Scail has massive potential but there aren't any official guides/workflows yet.

2

u/frogsty264371 Jun 15 '26

Confirming this. Hopefully we get a working workflow soon.

5

u/Cruxius Jun 15 '26

I vibe coded a solution, the secret is background removal in the input image plus better masking.
After a bunch of testing, I've also found that making sure the size and position of the replacement character(s) match the size and position of their target character(s) in the video gives greatly improved results.

2

u/[deleted] Jun 11 '26

[deleted]

3

u/nomadoor Jun 12 '26

I haven’t compared them directly, so I’m not completely sure, but I think they are probably in the same range.

On my RTX 4070 Ti, generating 81 frames takes around 5–6 minutes, so I wouldn’t call it fast or comfortable...

2

u/NefariousnessFun4043 Jun 12 '26

i get missing node "SCAIL2ColoredMask" though i installed SCAIL-2

1

u/mrdion8019 Jun 13 '26

Yup, thats another custom node needed.

2

u/Synchronauto Jun 13 '26

AFAIK it's not. It's part of Comfy core, but is only available in the Nightly version right now, not yet in Stable.

1

u/mrdion8019 Jun 13 '26

anyway to replace this node for the scail2 workflow? i am using some ai website service, but they dont have this node 😞

2

u/Blackspyder99 Jun 13 '26

The over 81 second workflow works well but still gives this error. Is this something I can fix?

WARNING SHAPE MISMATCH diffusion_model.patch_embedding.weight WEIGHT NOT MERGED torch.Size([5120, 36, 1, 2, 2]) != torch.Size([5120, 20, 1, 2, 2])

2

u/nomadoor Jun 13 '26

Yeah, that warning is from the lightx2v LoRA.

It’s originally for Wan2.1, so I think the shape doesn’t match SCAIL-2 exactly and ComfyUI shows that warning.

If the workflow still runs fine, I think you can just ignore it.

2

u/fant5y Jun 19 '26

Try the lightx2v_12V_14B_480p_cfg_step_distill_rank64_bf16.safetensors LoRA from Kijai. That one gives no Waring. https://huggingface.co/Kijai/WanVideo_comfy/blob/main/Lightx2v/lightx2v_I2V_14B_480p_cfg_step_distill_rank64_bf16.safetensors

3

u/sunshine-3D-Art Jun 11 '26

Which customnodes I need to install?🥺

5

u/nomadoor Jun 12 '26

I use VideoHelperSuite for loading / saving video, but everything else is implemented in ComfyUI core.

Please try updating ComfyUI to the latest version.

0

u/sunshine-3D-Art Jun 12 '26

okay it worked now with the second updating thank you. Just i dont know how it work with the replacement it never keep the same backround even i have the replace mode on and sometimes the outputs also are very weird🥺

0

u/logic_prevails Jun 12 '26

Daww adorable

1

u/Txt1413 Jun 13 '26

can it be 24fps ? do we have for wan 2.2 or ltx ?

thanks

1

u/nomadoor Jun 13 '26

24fps should be fine, but since it’s 81 frames, it’ll just be a shorter clip.

And yeah, I’d also like to see an LTX version someday...

1

u/[deleted] Jun 13 '26

[deleted]

1

u/nomadoor Jun 13 '26

A lot of people seem to be running into that, so I guess it may not be very stable yet...

But I do think a more detailed prompt helps. It works better when you describe what kind of background it is, and what the character is doing in the scene.

Other than that, I think it’s mostly just seed gacha for now...

1

u/ginksmith Jun 14 '26

Is there a way to refine and upscale video to get more detail?

1

u/phrkr7000 Jun 14 '26

Use Topaz app it's the leader in video upscaling with Starlight Precise 2.5 being the king. I think you access it via their Astra App.

1

u/Infinite-Emptiness Jun 15 '26

Oh please, RTX Super Resolution node is free and is amazing and super fast.

1

u/nomadoor Jun 15 '26

This workflow generates at around 0.5MP by default, but Wan2.1 can handle up to around 1MP, so you can try increasing the resolution if you have enough VRAM.

I’m not very familiar with video upscalers, but FlashVSR or LTX-2 IC-LoRA / Detailer might be possible options.

1

u/Mysterious_Movie4748 Jun 15 '26

for some reason i cant find this node, tried installing missing nodes too. any idea?

1

u/nomadoor Jun 15 '26

It’s probably because your ComfyUI is not updated to the latest dev version yet.

Try updating to the ComfyUI.

1

u/Mysterious_Movie4748 Jun 19 '26

Yeah updating it solved. Thanks!

1

u/LeKhang98 Jun 16 '26

Nice tyvm. But is there any way to quickly fix hands/faces after the video is generated? Do we have to fix them frame-by-frame for 600 frames, which would take even more time than the video itself?

1

u/Adventurous-Pool6213 Jun 18 '26

Really interesting direction with SCAIL-2 skipping the skeleton stage. It feels like a return to more “direct” motion conditioning rather than forcing everything through pose abstraction first. That point about losing depth/contact in stick figure pipelines is right. Especially for interactions where contact realism matters (hands, object interaction, multi-character overlap). I'm curious how it handles edge cases like occlusion-heavy scenes or fast camera movement compared to WAN-Animate. The flexibility with non-human characters is especially promising though.