ComfyUI-VACE-Tools

ComfyUI custom nodes for WanVideo/VACE workflows — mask/control-frame generation and model saving.

Installation

cd ComfyUI/custom_nodes/
git clone https://github.com/ethanfel/Comfyui-VACE-Tools.git

Restart ComfyUI. Nodes appear under the VACE Tools and WanVideoWrapper categories.

Node: VACE Source Prep

Trims long source clips so they can be used with VACE Mask Generator. Place this node before the mask generator when your source clip has more frames than target_frames. It selects the relevant frames based on mode and outputs adjusted parameters to wire directly into the mask generator.

Irrelevant widgets are automatically hidden based on the selected mode.

Inputs

Input	Type	Default	Description
source_clip	IMAGE	—	Full source video frames (B, H, W, C tensor).
mode	ENUM	End Extend	Generation mode — must match the mask generator's mode.
split_index	INT	0	Split position in the full source video. Same meaning as the mask generator's split_index.
input_left	INT	0	Frames from the left side of the split point to keep (0 = all available). End: trailing context. Middle: frames before split. Edge/Join: start edge size. Bidirectional: trailing context. Replace: context before region.
input_right	INT	0	Frames from the right side of the split point to keep (0 = all available). Pre: leading reference. Middle: frames after split. Edge/Join: end edge size. Replace: context after region.
edge_frames	INT	8	Default edge size for Edge/Join modes (overridden by input_left/input_right if non-zero). Replace/Inpaint: number of frames to replace.
inpaint_mask	MASK	(optional)	Spatial inpaint mask — trimmed to match output frames for Video Inpaint mode.
keyframe_positions	STRING	(optional)	Keyframe positions pass-through for Keyframe mode.

Outputs

Output	Type	Description
source_clip	IMAGE	Trimmed frames — wire to mask generator's source_clip.
mode	STRING	Selected mode — wire to mask generator's mode (convert widget to input).
split_index	INT	Adjusted for the trimmed clip — wire to mask generator.
edge_frames	INT	Adjusted/passed through — wire to mask generator.
segment_1–segment_4	IMAGE	Frame segments per mode (same meaning as mask generator segments). Unused segments are 1-frame black placeholders.
inpaint_mask	MASK	Trimmed to match output, or placeholder.
keyframe_positions	STRING	Pass-through.
trim_start	INT	Start index of the trimmed region in the original clip — wire to VACE Merge Back.
trim_end	INT	End index of the trimmed region in the original clip — wire to VACE Merge Back.

Per-Mode Trimming

Mode	input_left	input_right	Behavior
End Extend	Trailing context frames	—	Keeps last N frames
Pre Extend	—	Leading reference frames	Keeps first N frames
Middle Extend	Frames before split	Frames after split	Window around split_index
Edge Extend	Start edge size	End edge size	Overrides edge_frames; forced symmetric (min of both)
Join Extend	Edge from first half	Edge from second half	Edge context around midpoint; forced symmetric
Bidirectional	Trailing context frames	—	Keeps last N frames
Frame Interpolation	—	—	Pass-through (no trimming)
Replace/Inpaint	Context before region	Context after region	Window around replace region
Video Inpaint	—	—	Pass-through (no trimming)
Keyframe	—	—	Pass-through (no trimming)

---

Node: VACE Mask Generator

Builds mask and control_frames sequences for all VACE generation modes. Works standalone for short clips, or downstream of VACE Source Prep for long clips.

Note: For modes that use target_frames (End, Pre, Middle, Edge, Join, Bidirectional, Keyframe), source_clip must not have more frames than target_frames. If your source is longer, use VACE Source Prep upstream to trim it first.

Inputs

Input	Type	Default	Description
source_clip	IMAGE	—	Source video frames (B, H, W, C tensor). Must not exceed target_frames for modes that use it.
mode	ENUM	End Extend	Generation mode (see below). 10 modes available.
target_frames	INT	81	Total output frame count for mask and control_frames (1–10000). Used by Keyframe to set output length. Unused by Frame Interpolation, Replace/Inpaint, and Video Inpaint.
split_index	INT	0	Where to split the source. Meaning varies by mode. Unused by Edge/Join/Keyframe. Bidirectional: frames before clip (0 = even split). Frame Interpolation: new frames per gap. Replace/Inpaint: start index of replace region.
edge_frames	INT	8	Number of edge frames for Edge and Join modes. Replace/Inpaint: number of frames to replace. Unused by End/Pre/Middle/Bidirectional/Frame Interpolation/Video Inpaint/Keyframe.
inpaint_mask	MASK	(optional)	Spatial inpaint mask for Video Inpaint mode (B, H, W). White (1.0) = regenerate, Black (0.0) = keep. Single frame broadcasts to all source frames.
keyframe_positions	STRING	(optional)	Comma-separated frame indices for Keyframe mode (e.g. 0,20,50,80). One position per source frame, sorted ascending, within [0, target_frames-1]. Leave empty for even auto-spread.

Outputs

Output	Description
mask	Black/white frame sequence (target_frames long). Black = keep, White = generate.
control_frames	Source frames composited with grey (#7f7f7f) fill (target_frames long). Fed to VACE as visual reference.
segment_1–segment_4	Clip segments whose contents depend on the mode (see below). Unused segments are 1-frame black placeholders.
frames_to_generate	INT — number of new frames the model needs to produce (the white/grey region).

Mode Reference

All diagrams show the mask and control_frames layout left-to-right (frame 0 → frame N).

---

End Extend

Generate new frames after the source clip.

• split_index — optional trim: 0 keeps the full clip; a negative value (e.g. -16) drops that many frames from the end before extending.
• frames_to_generate = target_frames − source_frames

mask:           [ BLACK × source ][ WHITE × generated ]
control_frames: [ source clip    ][ GREY  × generated ]

Segment	Content
segment_1	Source frames (trimmed if split_index ≠ 0)
segment_2–4	Placeholder

---

Pre Extend

Generate new frames before a reference portion of the source clip.

• split_index — how many frames from the start to keep as the reference tail (e.g. 24).
• frames_to_generate = target_frames − split_index

mask:           [ WHITE × generated ][ BLACK × reference ]
control_frames: [ GREY  × generated ][ reference frames  ]

Segment	Content
segment_1	Remaining frames after the reference (source[split_index:])
segment_2–4	Placeholder

---

Middle Extend

Generate new frames between two halves of the source clip, split at split_index.

• split_index — frame index where the source is split.
• frames_to_generate = target_frames − source_frames

mask:           [ BLACK × part_a ][ WHITE × generated ][ BLACK × part_b ]
control_frames: [ part_a         ][ GREY  × generated ][ part_b         ]

Segment	Content
segment_1	Part A — source[:split_index]
segment_2	Part B — source[split_index:]
segment_3–4	Placeholder

---

Edge Extend

Generate a transition between the end and start of a clip (useful for looping).

• edge_frames — number of frames taken from each edge.
• split_index — unused.
• frames_to_generate = target_frames − (2 × edge_frames)

The end segment is placed first, then the generated gap, then the start segment — so the model learns to connect the clip's end back to its beginning.

mask:           [ BLACK × end_seg ][ WHITE × generated ][ BLACK × start_seg ]
control_frames: [ end_seg         ][ GREY  × generated ][ start_seg         ]

Segment	Content
segment_1	Start edge — source[:edge_frames]
segment_2	Middle remainder — source[edge_frames:−edge_frames]
segment_3	End edge — source[−edge_frames:]
segment_4	Placeholder

---

Join Extend

Heal/blend two halves of a clip together. The source is split in half; edge_frames from each side of the split form the context.

• edge_frames — context frames taken from each side of the midpoint.
• split_index — unused.
• frames_to_generate = target_frames − (2 × edge_frames)

source layout:  [ part_1 ][ part_2 | part_3 ][ part_4 ]
                           ← edge →  ← edge →

mask:           [ BLACK × part_2 ][ WHITE × generated ][ BLACK × part_3 ]
control_frames: [ part_2         ][ GREY  × generated ][ part_3         ]

Segment	Content
segment_1	Part 1 — first half minus its trailing edge
segment_2	Part 2 — trailing edge of first half
segment_3	Part 3 — leading edge of second half
segment_4	Part 4 — second half minus its leading edge

---

Bidirectional Extend

Generate new frames both before and after the source clip.

• split_index — number of generated frames to place before the clip. 0 = even split (half before, half after).
• target_frames — total output frame count.
• frames_to_generate = target_frames − source_frames

mask:           [ WHITE × pre ][ BLACK × source ][ WHITE × post ]
control_frames: [ GREY  × pre ][ source clip    ][ GREY  × post ]

Segment	Content
segment_1	Full source clip
segment_2–4	Placeholder

---

Frame Interpolation

Insert generated frames between each consecutive pair of source frames.

• split_index — number of new frames to insert per gap (min 1). target_frames is unused.
• frames_to_generate = (source_frames − 1) × split_index
• Total output = source_frames + frames_to_generate

mask:           [ B ][ W×step ][ B ][ W×step ][ B ] ...
control_frames: [ f0][ GREY   ][ f1][ GREY   ][ f2] ...

Segment	Content
segment_1	Full source clip
segment_2–4	Placeholder

---

Replace/Inpaint

Regenerate a range of frames in-place within the source clip.

• split_index — start index of the region to replace (clamped to source length).
• edge_frames — number of frames to replace (clamped to remaining frames after start).
• frames_to_generate = edge_frames (after clamping). target_frames is unused.
• Total output = source_frames (same length — in-place replacement).

mask:           [ BLACK × before ][ WHITE × replace ][ BLACK × after ]
control_frames: [ before frames  ][ GREY  × replace ][ after frames  ]

Segment	Content
segment_1	Before — source[:start]
segment_2	Original replaced frames — source[start:start+length]
segment_3	After — source[start+length:]
segment_4	Placeholder

---

Video Inpaint

Regenerate spatial regions within frames using a per-pixel mask. Unlike other modes that work at the frame level (entire frames kept or generated), Video Inpaint operates at the pixel level — masked regions are regenerated while the rest of each frame is preserved.

• inpaint_mask (required) — a MASK (B, H, W) where white (1.0) marks regions to regenerate and black (0.0) marks regions to keep. A single-frame mask is automatically broadcast to all source frames; a multi-frame mask must have the same frame count as source_clip.
• target_frames, split_index, edge_frames — unused.
• frames_to_generate = source_frames (all frames are partially regenerated).
• Total output = source_frames (same length — in-place spatial replacement).

Compositing formula per pixel:

control_frames = source × (1 − mask) + grey × mask

mask:           [ per-pixel mask broadcast to (B, H, W, 3)        ]
control_frames: [ source pixels where mask=0, grey where mask=1   ]

Segment	Content
segment_1	Full source clip
segment_2–4	Placeholder

---

Keyframe

Place keyframe images at specific positions within a target_frames-length output, and generate everything between them.

• source_clip — a small batch of keyframe images (e.g. 4 frames).
• target_frames — total output frame count.
• keyframe_positions (optional) — comma-separated frame indices (e.g. "0,20,50,80"). Must have one value per source frame, sorted ascending, no duplicates, all within [0, target_frames-1]. Leave empty for auto-spread (first keyframe at frame 0, last at target_frames-1, others evenly distributed).
• split_index, edge_frames — unused.
• frames_to_generate = target_frames − source_frames
• Total output = target_frames

Example: 4 keyframes, target_frames=81, positions auto-spread to 0,27,53,80

mask:           [ B ][ W×26 ][ B ][ W×25 ][ B ][ W×26 ][ B ]
control_frames: [ k0][ GREY ][ k1][ GREY ][ k2][ GREY ][ k3]

Segment	Content
segment_1	Full source clip (keyframe images)
segment_2–4	Placeholder

---

Node: VACE Merge Back

Splices VACE sampler output back into the original full-length video. Connect the original (untrimmed) clip, the VACE sampler output, the mask from VACE Mask Generator, and the mode/trim_start/trim_end from VACE Source Prep.

Irrelevant widgets are automatically hidden based on the selected blend method.

Inputs

Input	Type	Default	Description
original_clip	IMAGE	—	Full original video (before any trimming).
vace_output	IMAGE	—	VACE sampler output.
mask	IMAGE	—	Mask from VACE Mask Generator — BLACK=context, WHITE=generated.
mode	STRING	(wired)	Mode from VACE Source Prep (must be wired, not typed).
trim_start	INT	(wired)	Start of trimmed region in original (from VACE Source Prep).
trim_end	INT	(wired)	End of trimmed region in original (from VACE Source Prep).
blend_frames	INT	4	Context frames to blend at each seam (0 = hard cut).
blend_method	ENUM	optical_flow	none (hard cut), alpha (linear crossfade), or optical_flow (motion-compensated).
of_preset	ENUM	balanced	Optical flow quality: fast, balanced, quality, max.

Outputs

Output	Type	Description
merged_clip	IMAGE	Full reconstructed video.

Behavior

Pass-through modes (Edge Extend, Frame Interpolation, Keyframe, Video Inpaint): returns vace_output as-is — the VACE output IS the final result for these modes.

Splice modes (End, Pre, Middle, Join, Bidirectional, Replace): reconstructs original[:trim_start] + vace_output + original[trim_end:], then blends at the seams where context frames meet original frames.

The node detects context zones by counting consecutive black frames at the start and end of the mask. At each seam, blend_frames frames are blended with a smooth alpha ramp. Optical flow blending warps both frames along the motion field before blending, reducing ghosting on moving subjects.

Example: Middle Extend

Original:  274 frames (0–273)
Prep:      split_index=137, input_left=16, input_right=16
           → trim_start=121, trim_end=153, trimmed=32 frames
Mask Gen:  target_frames=81
           → mask = [BLACK×16] [WHITE×49] [BLACK×16]
VACE out:  81 frames (from sampler)
Merge:     result = original[0:121] + vace[0:81] + original[153:274]
           → 121 + 81 + 121 = 323 frames
           Left blend:  vace[0..3] ↔ original[121..124]
           Right blend: vace[77..80] ↔ original[149..152]

Wiring Diagram

[Load Video]
     │
     ├─ source_clip ──→ [VACESourcePrep] ─┬─ source_clip ──→ [MaskGen] ─→ mask ──┐
     │                                     ├─ mode ───────────────────────────────┤
     │                                     ├─ trim_start ─────────────────────────┤
     │                                     └─ trim_end ──────────────────────────┤
     │                                                                            │
     └─ original_clip ───────────────────────────────────────────────────────────→ [VACEMergeBack]
                                                                                  │
                                        [Sampler] ─→ vace_output ────────────────┘

---

Node: WanVideo Save Merged Model

Saves a WanVideo diffusion model (with merged LoRAs) as a .safetensors file. Found under the WanVideoWrapper category.

Inputs

Input	Type	Default	Description
model	WANVIDEOMODEL	—	WanVideo model with merged LoRA from the WanVideo Model Loader.
filename_prefix	STRING	merged_wanvideo	Filename prefix for the saved file. A numeric suffix is appended to avoid overwriting.
save_dtype	ENUM	same	Cast weights before saving: same, bf16, fp16, or fp32. Set explicitly if the model was loaded in fp8.
custom_path	STRING	(optional)	Absolute path to save directory. Leave empty to save in ComfyUI/models/diffusion_models/.

Behavior

• Extracts the diffusion model state dict and saves it in safetensors format.
• Records source model name and merged LoRA details (names + strengths) in file metadata for traceability.
• Clones all tensors before saving to handle shared/aliased weights safely.
• Automatically avoids overwriting existing files by appending _1, _2, etc.

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Node: Save Latent (Absolute Path)

Saves a LATENT to an absolute file path as .latent (safetensors format). Found under the latent category.

Inputs

Input	Type	Default	Description
samples	LATENT	—	Latent samples to save.
path	STRING	/path/to/latent.latent	Absolute file path. .latent extension is appended if missing.
overwrite	BOOLEAN	False	If false, appends _1, _2, etc. to avoid overwriting.

Outputs

Output	Description
LATENT	Pass-through of the input samples (for chaining).

Behavior

• Saves all tensor data via safetensors, with device info and non-tensor metadata stored in the file header.
• Creates parent directories automatically.

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Node: Load Latent (Absolute Path)

Loads a LATENT from an absolute file path. Found under the latent category.

Inputs

Input	Type	Default	Description
path	STRING	/path/to/latent.latent	Absolute path to a .latent file previously saved by Save Latent.

Outputs

Output	Description
LATENT	Restored latent samples with original devices and non-tensor data.

Dependencies

• PyTorch and safetensors — bundled with ComfyUI.
• OpenCV (cv2) — optional, for optical flow blending in VACE Merge Back. Falls back to alpha blending if unavailable.