README(1).md

WanKeyframeBuilder

ComfyUI custom nodes for building keyframe timelines for Wan video generation workflows.

Nodes

WanKeyframeBuilder

Basic keyframe timeline builder for single-pass video generation.

Inputs:

• image1-8: Up to 8 keyframe images
• num_frames: Total timeline length (default 81, should be 4n+1)
• spacing_mode: Even distribution or manual positioning
• first_strength, last_strength, middle_strength: Mask strengths for keyframes

Outputs:

• images: Full timeline [T, H, W, C] with keyframes placed and gray (0.5) fill
• masks: Strength masks [T, H, W] for each position
• keyframes: Just the keyframe images [N, H, W, C]

WanKeyframeBuilderContinuation

Advanced keyframe builder for multi-segment video generation with continuation support.

Key Features:

• Continuation frames from previous video segment for smooth transitions
• First keyframe can be placed immediately after continuation frames
• Multiple reference images for scene transitions
• SVI-specific outputs for experimental SVI 2.0 workflows

Inputs:

• image1: Reference image for HuMo/quality
• image2-8: Timeline keyframes (optional, placed on timeline)
• continuation_image: Last N frames from previous generation
• continuation_frames: Number of frames to use (default 3)
• place_first_keyframe: Place image2 immediately after continuation frames (default True)
• first_keyframe_strength: Mask strength for placed first keyframe (default 1.0)

Continuation Frame Handling:

• IMPORTANT: Continuation frames are now in chronological order (reversal logic removed)
• Takes last N frames from previous video in order: oldest → newest
• Position 0 = oldest continuation frame
• Position N-1 = newest continuation frame
• This matches standard video continuation expectations

Mask Strength Modes:

• uniform: All continuation frames use same strength
• decay: Exponential decay from start strength to end strength
  • continuation_strength_start: Strength for first/oldest frame (default 0.8)
  • continuation_strength_end: Strength for last/newest frame (default 0.2)
  • continuation_decay_rate: Decay curve (3.0 = moderate, 5.0+ = aggressive)

Outputs:

• images: Standard timeline with continuation + keyframes + gray fill
• masks: Strength masks
• keyframes: All reference images [image1, image2, ...] for HuMo/multi-reference
• svi_reference_only: EXPERIMENTAL - Timeline with image1 padding for SVI-Shot
• svi_keyframe_segments: EXPERIMENTAL - Each keyframe fills equal segments for SVI 2.0

SVI Outputs (Experimental)

The svi_reference_only and svi_keyframe_segments outputs are designed for use with Stable Video Infinity (SVI) 2.0 LoRAs.

⚠️ WARNING: These outputs are experimental and NOT confirmed to work with SVI workflows.

The SVI outputs were designed based on documentation from the Stable-Video-Infinity repository, but have not been tested with actual SVI LoRAs in Kijai's WanVideoWrapper.

svi_reference_only

Timeline filled entirely with image1 (except continuation frames).

Intended for: SVI-Shot style reference padding where a single reference image persists throughout generation.

[0-2]: Continuation frames
[3-80]: image1 duplicated

svi_keyframe_segments

Timeline where each keyframe fills its segment equally.

Intended for: SVI 2.0 multi-reference workflows with smooth transitions between different reference images.

With 3 continuation frames + 3 timeline keyframes (image2, image3, image4):

[0-2]: Continuation frames
[3-28]: image2 padding (segment 1)
[29-54]: image3 padding (segment 2)
[55-80]: image4 padding (segment 3)

If you test these outputs: Please report back whether they work with SVI LoRAs!

Installation

cd ComfyUI/custom_nodes
git clone https://github.com/yourusername/WanKeyframeBuilder
# Restart ComfyUI

Example Workflow

Basic Single-Pass Generation

WanKeyframeBuilder
├─ image1-5: Your keyframe images
├─ num_frames: 81
├─ spacing_mode: even
└─ Outputs → WanVideoImageToVideoEncode → WanVideoSampler

Multi-Segment Generation with Continuation

Segment 1:
├─ WanKeyframeBuilderContinuation
│  ├─ image1: Reference face
│  ├─ image2-4: First segment keyframes
│  └─ continuation_image: None
└─ Generate 81 frames

Segment 2:
├─ WanKeyframeBuilderContinuation
│  ├─ image1: Same or new reference
│  ├─ image2-4: Second segment keyframes  
│  └─ continuation_image: Last 10-20 frames from Segment 1
└─ Generate 81 frames (uses last 3 frames for motion continuity)

Technical Notes

Frame Position Calculation

Standard output (images):

• Continuation frames: positions 0 to N-1
• First keyframe (if place_first_keyframe=True): position N
• Remaining keyframes: distributed via spacing mode
• Empty positions: gray fill (0.5)

SVI outputs:

• Both start with image1 as base padding
• Continuation frames overwrite positions 0 to N-1
• svi_reference_only: Rest stays as image1
• svi_keyframe_segments: Rest divided into equal segments per keyframe

Mask Strength Behavior

Masks control how strongly each position is "locked" to its image:

• 1.0: Fully locked (no model freedom)
• 0.8: Strong guidance (recommended for middle keyframes)
• 0.5: Balanced
• 0.2-0.3: Light guidance (good for decay endpoints)
• 0.0: Free generation (gray areas)

Resolution Requirements

All connected images must match resolution. The node will raise an error if dimensions don't match. This is intentional - mismatched resolutions indicate a workflow error.

Changelog

Current Version

• BREAKING CHANGE: Removed continuation frame reversal logic
  • Frames now in chronological order (oldest → newest)
  • Matches standard video continuation expectations
  • Update workflows that relied on reversed order
• Added place_first_keyframe option for explicit first keyframe control
• Renamed continuation strength parameters for clarity (start/end instead of ceiling/floor)
• Added experimental SVI-specific outputs
• Improved mask strength calculation with clearer decay semantics

Previous Versions

• Initial release with basic keyframe building
• Added continuation support
• Added SVI experimental outputs

Credits

Designed for use with:

• Kijai's WanVideoWrapper
• Stable Video Infinity (experimental)
• Wan 2.1/2.2 video generation models

License

[Your License Here]