MoviiGen VACE GGUF + CausVid LoRA (14B 720P I2V & Video Extension)

This experimental ComfyUI workflow supports:

• Image-to-Video (I2V) and Video Extension (V2V) generation using MoviiGen1.1-VACE-GGUF

• Using CausVid LoRA with 2 samplers for faster generations

You can:

• Generate the first video as your starting point

• Extend the video one at a time to gradually build out the full sequence

• Cherry-pick the best segments for your final cut

• Refine prompts step-by-step as the scene or motion evolves

🔧 Components

🌀 MoviiGen1.1-VACE-GGUF (by Finanzamt_Endgegner)

• Based on Wan2.1, fine-tuned on cinematic 720p+ videos

• VACE (All-in-One Video Creation and Editing framework) allows motion control using reference videos (like ControlNet for video)

• Native support in ComfyUI via GGUF format

• Temporal consistency across the full sequence

Model Downloads:

• Model on Hugging Face

Official Repo:

• HuggingFace: MoviiGen

• GitHub: VACE

Related:

• Reddit: What VACE Does

• Reddit: What MoviiGen Does

• HuggingFace: VACE Example Workflow

⚡ CausVid LoRA (by Kijai)

• Speeds up Wan2.1-based video workflows

• Works best with two samplers (based on Maraan666):

  • First few steps: without CausVid LoRA

  • Remaining steps: with CausVid LoRA

  • Improves motion without suppressing natural movement

LoRA Downloads:

• 14B: Download
  Source: lightx2v/Wan2.1-T2V-14B-CausVid

• 1.3B: Download
  Source: tianweiy/CausVid - Bidirectional Checkpoint 2

Official Repo:

• GitHub: CausVid

Related:

• CivitAI: Causvid Lora, massive speedup for Wan2.1 made by Kijai

• Reddit: Causvid Lora, massive speedup for Wan2.1 made by Kijai

• Reddit: CausVid with Two Samplers

▶️ How to Use

🖼️ To Generate Video from an Image as First Frame

1. Enable "First Frame" from the muter node

2. Upload your input image

3. Set generation parameters:

   • Prompts (positive/negative)

   • Shift

   • Steps

   • Seed

   • Width / Height

   • Length (frame count)

   • Sampler

   • Scheduler

4. Click Run

🎥 To Extend an Existing Video

1. Enable "Video Extension" and "Combine" options

2. Upload your input video

3. Set extension parameters:

   • Overlap Frame Count

   • Extension Frame Count

   • Prompts (positive/negative)

   • Shift

   • Steps

   • Seed

   • Sampler

   • Scheduler

4. Click Run

⚠️ Challenges and Limitations

The base model is a T2V model, not a true I2V model.

The I2V is achieved by feeding a reference image into the VACE node, rather than directly preserving the image.

An I2V model typically keeps the input image as the exact first frame.

Here, VACE treats the image as loose guidance, not strict visual preservation

Examples:

• If your source image lacks an object, but your prompt includes it, that object might be added to the first frame.

• If the prompt contradicts the image, some original elements may be missing.

• Fine details may degrade over time, especially in extended video generations.

📂 References

• MoviiGen + VACE Overview (Reddit)

• causvid wan img2vid - improved motion with two samplers in series (Reddit)

• VACE Examples (HuggingFace)

• SkyReels Diffusion Extension Example (GitHub)

• VACE Extension is the next level beyond FLF2V (Reddit)

• Loop Anything with Wan2.1 VACE (Reddit)

FAQ (Frequently Asked Questions)

❓ Can I run this with 16GB VRAM?

Yes. I ran it on an RTX 5060 Ti with 16GB VRAM using the Q6_K GGUF model.

With GGUF models, you can choose a version that fits your GPU memory:

• Q3_X_X (3-bit) for ~8GB VRAM

• Q4_X_X (4-bit) for ~12GB

• Q5–Q6 for ~16GB

• Q8 for ~24GB+

👉 Model & hardware info: https://huggingface.co/QuantStack/MoviiGen1.1-VACE-GGUF

❓ Why do I get errors or bad video clips?

This workflow is still experimental, so crashes or poor results are common. Here are some tips:

• OOM (out of memory) error = your GPU doesn’t have enough VRAM

• Use a lower quant model (e.g. Q3 or Q4) to reduce memory usage

• Lower the video resolution or clip length to avoid overload

• If transitions look bad, try adjusting the prompt or other settings

• Generate multiple times, then pick the best clips to stitch together

❓ Why does "WanVaceToVideo" give an error with certain resolutions?

The "WanVaceToVideo" model only accepts resolutions where both width and height are divisible by 16. If your input resolution doesn’t meet this requirement, you’ll likely run into errors or processing failures.

Below are safe resolutions for commonly used aspect ratios, based on standard output heights (320, 368, 480, 544, 640, 720):

✅ Recommended Aspect Ratios & Resolutions (All values divisible by 16)

• 🖥 32:9 -> 1136x320

• 📽 21:9 -> 752x320, 864×368, 1120×480, 1264×544

• 🖼 2:1 -> 640x320, 736×368, 960×480, 1088×544, 1280×640

• 📺 16:9 -> 576x320, 656×368, 848×480, 960×544, 1136×640, 1280×720

• 🖥 16:10 -> 512x320, 592×368, 768×480, 864×544, 1024×640, 1152×720

• 📷 3:2 -> 480x320, 560×368, 720×480, 816×544, 960×640, 1088×720

• 🖼 4:3 -> 432x320, 496×368, 640×480, 720×544, 848×640, 960×720

• 🖼 5:4 -> 400x320, 464×368, 608×480, 688×544, 800×640, 896×720