ComfyUI StoryMem Nodes

Custom ComfyUI nodes for StoryMem - Multi-shot long video storytelling with memory-conditioned video diffusion models.

Overview

StoryMem is an AI system that generates extended narrative videos from text prompts. These ComfyUI nodes allow you to create minute-long, multi-shot videos with consistent characters and cinematic quality directly in ComfyUI workflows.

Features

• Shot-level control: Generate videos shot-by-shot with full control over each segment
• Memory-conditioned generation: Maintain character and scene consistency across shots
• Three generation modes: M2V (memory-only), MI2V (memory+first-frame), MM2V (memory+motion)
• Flexible workflows: Chain nodes together to create complex narratives
• ComfyUI integration: Native tensor format support and model management

Requirements

Hardware

• GPU: NVIDIA GPU with 80GB VRAM (for full models) or 24GB+ VRAM (with optimizations)
• Storage: ~40-60GB for model files
• RAM: 32GB+ recommended

Software

• ComfyUI (latest version)
• Python 3.10 or 3.11
• CUDA 11.8 or higher
• PyTorch 2.4.0 or higher

Installation

Method 1: ComfyUI Manager (Recommended - Coming Soon)

1. Open ComfyUI Manager
2. Search for "StoryMem"
3. Click Install
4. Restart ComfyUI
5. Download models (see below)

Method 2: Manual Installation

# Navigate to ComfyUI custom_nodes directory
cd ComfyUI/custom_nodes

# Clone this repository
git clone https://github.com/[your-username]/comfyui_storymem.git
cd comfyui_storymem

# Install dependencies
pip install -r requirements.txt

# Optional: Install flash attention for better performance
pip install flash-attn --no-build-isolation

# Optional: Install xformers for memory efficiency
pip install xformers

Downloading Models

The StoryMem models are large (~40-60GB total). You can download them using the provided script:

python scripts/download_models.py

Or manually using HuggingFace CLI:

# Create models directory in ComfyUI
mkdir -p ../../models/storymem

# Download T2V model (~20-30GB)
huggingface-cli download Wan-AI/Wan2.2-T2V-A14B --local-dir ../../models/storymem/Wan2.2-T2V-A14B

# Download I2V model (~20-30GB)
huggingface-cli download Wan-AI/Wan2.2-I2V-A14B --local-dir ../../models/storymem/Wan2.2-I2V-A14B

# Download M2V LoRA weights
huggingface-cli download Kevin-thu/StoryMem --local-dir ../../models/storymem/StoryMem

Model Storage Location: Models should be placed in ComfyUI/models/storymem/

Available Nodes

StoryMem Model Loader

Loads and caches the three StoryMem models (T2V, I2V, M2V LoRA).

Inputs:

• t2v_model: Text-to-Video model selection
• i2v_model: Image-to-Video model selection
• m2v_lora: LoRA type (MI2V or MM2V)
• device: Device selection (auto/cuda/cpu)
• enable_offload: Enable CPU offloading for VRAM management

Outputs: STORYMEM_MODELS

StoryMem Memory Buffer

Creates and configures a memory buffer for shot-to-shot continuity.

Inputs:

• max_memory_size: Maximum keyframes to retain (default: 10)
• fixed_frames: Number of earliest frames to always keep (default: 3)

Outputs: STORYMEM_MEMORY

StoryMem First Shot

Generates the first shot of a story using T2V model.

Inputs:

• models: STORYMEM_MODELS from loader
• prompt: Text description (multiline)
• num_frames: Frame count (default: 25, must be 4n+1)
• width, height: Resolution (default: 832x480)
• seed, steps, cfg_scale: Generation parameters
• use_t2v: Use T2V vs M2V for first shot

Outputs: VIDEO, STORYMEM_MEMORY, IMAGE (last frame)

StoryMem Continuation Shot

Generates subsequent shots with memory conditioning.

Inputs:

• models: STORYMEM_MODELS
• memory: STORYMEM_MEMORY from previous shot
• prompt: Text description
• generation_mode: M2V / MI2V / MM2V
• num_frames, seed, steps, cfg_scale: Generation parameters
• is_scene_cut: Reset memory for scene transitions

Outputs: VIDEO, STORYMEM_MEMORY (updated), IMAGE (last frame)

Generation Modes:

• M2V: Memory-only conditioning (most flexible)
• MI2V: Memory + first frame (better continuity)
• MM2V: Memory + 5 motion frames (smoothest transitions)

StoryMem Memory Visualizer

Visualizes the current state of the memory buffer.

Inputs: STORYMEM_MEMORY Outputs: IMAGE (grid of keyframes)

StoryMem Video Combine

Concatenates multiple video shots into a single video.

Inputs: Multiple VIDEO inputs Outputs: Single VIDEO

Basic Workflow Example

[StoryMemModelLoader]
    ↓ models
[StoryMemMemoryBuffer] (max_size=10)
    ↓ memory
[StoryMemFirstShot]
    prompt: "A young woman walks through a bustling city street at sunset"
    ↓ video, memory, last_frame
[StoryMemContinuationShot]
    prompt: "She stops at a café window, looking at her reflection"
    mode: MI2V
    ↓ video, memory, last_frame
[StoryMemContinuationShot]
    prompt: "Inside the café, warm lighting illuminates the cozy interior"
    mode: M2V
    is_scene_cut: True
    ↓ video, memory, last_frame
[StoryMemVideoCombine]
    ↓ final_video
[VideoPreview]

Memory Management

Memory Buffer Strategy

StoryMem uses a sliding window approach:

• max_size: Total keyframes to retain (e.g., 10)
• fixed_frames: Earliest frames to always keep (e.g., 3)
• Strategy: Keep fixed_frames + most recent frames to fill remaining slots

This ensures:

• Long-term consistency (fixed frames preserve initial character appearance)
• Recent context (recent frames ensure smooth transitions)
• Bounded memory usage (never exceeds max_size)

VRAM Management

The full StoryMem models require ~80GB VRAM. To manage this:

1. Enable model offloading: Set enable_offload=True in ModelLoader
2. Use quantization: Consider quantized model versions (lower quality but much less VRAM)
3. Clear cache: ComfyUI automatically manages cache, but you can force-clear if needed
4. Sequential generation: Generate one shot at a time rather than batching

Tips for Best Results

1. Prompt writing: Be specific and descriptive. Include details about characters, setting, lighting, and camera angles.

2. Generation modes:

   • Use MI2V for smooth continuity within a scene
   • Use M2V for more variety or when scene cut occurs
   • Use MM2V for the smoothest transitions (requires more VRAM)

3. Scene cuts: Set is_scene_cut=True when transitioning to a completely new scene or location.

4. Memory size: Larger memory buffers (10-15) maintain consistency better but use more VRAM.

5. Resolution: Start with 832x480, increase to 720p if you have sufficient VRAM.

Troubleshooting

Out of Memory Errors

Problem: CUDA out of memory during model loading or generation.

Solutions:

• Enable enable_offload=True in ModelLoader
• Reduce num_frames (e.g., from 25 to 17 or 13)
• Lower resolution (e.g., 640x360)
• Close other VRAM-intensive applications
• Consider quantized model versions

Slow Generation

Problem: Generation takes a very long time.

Solutions:

• Install flash-attn and xformers for acceleration
• Reduce steps (try 30-40 instead of 50)
• Use M2V mode instead of MM2V (less conditioning data)
• Ensure models are on GPU, not CPU

Character Consistency Issues

Problem: Characters look different between shots.

Solutions:

• Increase max_memory_size (try 15-20)
• Use MI2V mode for better continuity
• Ensure is_scene_cut=False for same-scene transitions
• Use more detailed character descriptions in prompts

Model Download Fails

Problem: HuggingFace download interrupted or fails.

Solutions:

• Downloads are resumable - just run the command again
• Check disk space (~60GB needed)
• Check internet connection
• Try manual download from HuggingFace website

Technical Details

Tensor Formats

• ComfyUI format: [B, F, H, W, C] (batch, frames, height, width, channels)
• StoryMem format: [B, C, F, H, W] (channels first)
• Conversion is handled automatically by the nodes

Model Architecture

StoryMem uses:

• Wan2.2-T2V-A14B: 14B parameter text-to-video model with MoE architecture
• Wan2.2-I2V-A14B: 14B parameter image-to-video model
• M2V LoRA: Fine-tuned adaptation weights for memory conditioning

Keyframe Extraction

Keyframes are extracted using:

• CLIP embeddings for similarity detection
• HPSv3 for quality filtering
• Configurable similarity threshold (default: 0.9)
• Maximum keyframes per shot (default: 3)

Credits and License

This project wraps the original StoryMem repository.

Original StoryMem:

• Paper: StoryMem: Multi-Shot Long Video Storytelling with Memory
• Authors: Kevin Thu et al.
• License: Check the original repository for license details

ComfyUI Nodes:

• Repository: [Add your repo URL here]
• License: [Add your license here]

Support and Contributing

• Issues: Report bugs or request features via GitHub Issues
• Discussions: Join discussions on ComfyUI forums
• Contributing: Pull requests are welcome!

Changelog

v0.1.0 (Initial Release)

• Basic node implementations
• Model loader with offloading support
• Shot-level generation (First Shot, Continuation Shot)
• Memory buffer management
• Three generation modes (M2V, MI2V, MM2V)
• Video combination utilities

References

• StoryMem Paper
• StoryMem GitHub
• Wan2.2 Models on HuggingFace
• ComfyUI