This ComfyUI workflow performs automatic video object masking from a simple text phrase using the SAM3 Video Masking node (ID: 9cea40bb-b0cf-4b40-a758-8935cfe8d52f). You load a clip with VHS_LoadVideo, describe what you want to isolate (for example, "red car" or "person") in the node’s mask_prompt, and the system finds every matching instance, tracks them across frames with stable IDs, and produces three streams: a mask overlay preview, a raw per-frame binary mask, and a subject cut-out. SaveVideo nodes handle exporting the results.

Technically, VHS_LoadVideo provides a consistent frame sequence (fps, resolution) for inference. During iteration you can cap frames using frame_load_cap to preview quickly, then switch to a full pass by setting it to 0. The SAM3 Video Masking node interprets your text prompt, segments the target across frames, and maintains identity continuity so objects don’t flicker or swap. The outputs are suitable for downstream compositing, selective blurring, color grading, or background replacement. A MarkdownNote node in the graph provides inline tips and reminders while you work.