ComfyUI-SAM3

ComfyUI integration for Meta's SAM3 (Segment Anything Model 3) - enabling open-vocabulary image segmentation using natural language text prompts.

###Examples

Nodes

LoadSAM3Model

Loads the SAM3 model and creates a processor for inference.

Inputs:

• device (auto/cuda/cpu): Device to run the model on (default: auto)
• model_path (optional): Path to custom checkpoint (leave empty to auto-download)

Outputs:

• sam3_model: Model object to be used by segmentation nodes

Notes:

• First run will download the model (~3.2GB) from HuggingFace
• Model is cached in ComfyUI/models/sam3/sam3.pt
• Subsequent loads are instant (uses in-memory cache)

SAM3Segmentation

Performs segmentation using text prompts.

Inputs:

• sam3_model: Model from LoadSAM3Model node
• image: Input image (ComfyUI IMAGE format)
• text_prompt: Natural language description of objects to segment
  • Examples: "person", "cat", "person in red", "car on the left"
• confidence_threshold (0.0-1.0): Minimum confidence score (default: 0.5)
• max_detections (optional): Maximum number of detections to return (-1 for all)

Outputs:

• masks: Binary segmentation masks (ComfyUI MASK format)
• visualization: Image with colored mask overlays and bounding boxes
• boxes: JSON string containing bounding box coordinates [[x0, y0, x1, y1], ...]
• scores: JSON string containing confidence scores [0.95, 0.87, ...]

Example Prompts:

• Single object: "shoe", "cat", "person"
• With attributes: "person in red", "black car", "wooden table"
• Spatial relations: "person on the left", "car in the background"

SAM3GeometricRefine

Refines segmentation using geometric box prompts (advanced usage).

Inputs:

• sam3_model: Model from LoadSAM3Model node
• image: Input image
• box_x, box_y: Box center coordinates (normalized 0-1)
• box_w, box_h: Box width and height (normalized 0-1)
• is_positive: True for positive prompt, False for negative
• confidence_threshold: Minimum confidence score
• text_prompt (optional): Combine with text prompt

Outputs:

• Same as SAM3Segmentation

Notes:

• Box coordinates are normalized to [0, 1] range
• Positive prompts include the box region, negative prompts exclude it
• Can be combined with text prompts for more precise control

Credits

• SAM3: Meta AI Research (https://github.com/facebookresearch/sam3)
• ComfyUI Integration: ComfyUI-SAM3
• Interactive Points Editor: Adapted from ComfyUI-KJNodes by kijai (Apache 2.0 License). The SAM3PointsEditor node is based on the PointsEditor implementation from KJNodes, simplified for SAM3-specific point-based segmentation.