What It Does
Mask Prompter generates rotoscoping mattes using AI models that run locally on your machine. Instead of drawing masks frame by frame, you describe what to isolate with a text prompt, draw a bounding box, or click a single point on the subject. The plugin uses Segment Anything 3 and blace.ai models to analyze footage and produce alpha channels automatically.
You can isolate multiple objects in one pass by separating prompts with dots, for example “person.car.building”. A refinement module polishes edges to reduce artifacts before you commit to a final matte.
Key Features
Three input methods. Natural language text prompts, bounding rectangles for specific areas, and single-point tracking. Each suits different shot complexity and subject clarity.
Local processing. All AI computation happens on your machine. No footage is uploaded to any server.
Output options. Overlay preview, black-and-white matte, or alpha-channel content with transparent background. Detection boxes let you verify what the model identified before running the full matte.
Stable video tracking. Mattes stay consistent across frames rather than flickering, reducing the cleanup you’d otherwise do manually.
Refinement module. A secondary pass polishes edges from the initial AI output for cleaner compositing results.
Worth knowing: this works well for solid objects, vehicles, and shapes with clear boundaries. It’s not a replacement for precision roto on hair, translucency, or complex transparency.
Hardware requirements. Windows with an NVIDIA GPU (8GB+ VRAM recommended), or an Apple Silicon Mac running macOS Sequoia or later with 16GB+ RAM. Other hardware will run slowly or not at all.
Who It’s For
VFX artists and compositors who need fast mattes for background replacements, selective color grading, or element isolation without full manual roto. Good for shots with clearly defined subjects where the AI can produce reliable results with minimal cleanup.
Pricing
$49.99, one-time purchase. No subscription, no free trial. Owners of previous versions purchased after April 11, 2025 get version 3 free; earlier buyers pay $35 for the upgrade (applied automatically at checkout). Works in both After Effects and Premiere Pro.