Wan VACE Prep
ComfyUI nodes for preparing videos for Wan VACE generation - handles transitions and extensions with automatic control video generation.
Quick Start
What it does: Automates the tedious parts of VACE workflows by generating control videos and masks for smooth video transitions and extensions.
Install via ComfyUI Manager: Search for "Wan VACE Prep" → Install → Restart
Or clone this repository:
cd /path/to/comfyui/custom_nodes
git clone https://github.com/stuttlepress/ComfyUI-Wan-VACE-Prep
Nodes
Wan VACE Prep
For smoothly joining two video clips together. Builds VACE controls for the transition using context frames from each clip to guide frame generation.
- Builds VACE control video and mask from context frames in both clips
- Outputs video segments for final assembly
- Optional crossfade mode for artifact reduction in the surrounding workflow.
Parameters:
| Parameter | Default | Description |
|---|---|---|
| context_frames | 8 | Reference frames from each video edge that VACE uses for interpolation. These frames guide the model and are preserved in the output. Must be a multiple of 4. |
| replace_frames | 8 | Number of frames at each transition edge to discard and regenerate. These create the actual transition blend zone. Must be a multiple of 4. |
| add_frames | 0 | Number of completely new frames to generate between the two clips, extending the transition duration. Must be 0 or a multiple of 4. |
| crossfade_mode | false | When enabled, context frames are included in start_images and end_images so they can be blended with the context frames included in the VACE generated clip. This can help mitigate color or brightness artifacts at the transition. |
Outputs:
| Output | Description |
|---|---|
| control_video | VACE control video input |
| control_mask | VACE control mask input |
| width, height, length | Control video dimensions |
| start_images | Video 1 segment that precedes context frames and the transition |
| end_images | Video 2 segment that comes after the transition and context frames |
Wan VACE Extend
For smoothly extending a video. Context frames from before the chosen extension point are used to build a control video for VACE conditioning.
- Extends from arbitrary frame position
- Builds VACE control video and mask from context frames in the input video
- Outputs video segment preceding the extension for video reassembly
- Optional crossfade mode for artifact reduction in the surrounding workflow.
Parameters:
| Parameter | Default | Description |
|---|---|---|
| extend_from_idx | -1 | Frame to extend from (negative counts from end, e.g., -1 = last frame) |
| context_frames | 8 | Number of reference frames preceding extend_from_idx that VACE uses for interpolation. These frames guide the model and are preserved in the output. Must be a multiple of 4. |
| new_frames | 25 | Number of new frames to generate (must be 4n+1: e.g., 1, 5, 9, 13, 17, 25...) |
| crossfade_mode | false | When enabled, context frames are included in start_images so they can be blended with the context frames included in the VACE generated clip. This can help mitigate color or brightness artifacts at the transition. |
Outputs:
| Output | Description |
|---|---|
| control_video | VACE control video input |
| control_mask | VACE control mask input |
| width, height, length | Control video dimensions |
| start_images | Video segment that precedes the context frames and the start of the extension |
Technical Note
The Wan model likes to generate 4n+1 frames at a time. If you ask it for some other amount, it will silently round your request down to the nearest 4n+1. For this reason, parameters are restricted to multiples of 4 or 4n+1 and when necessary, the node adds +1 to the number of generated frames.
License
MIT License - feel free to use, modify, and distribute.