How to Generate B-Roll from Text and Images with AI

Generate to fill a known hole in the edit. “Cinematic startup b-roll” is not a shot brief.

Workflow

1. Lock a rough edit and list missing shots with purpose, duration, framing, subject, action, environment, camera, and exit motion.
2. Create or choose an approved first frame. Image-to-video usually preserves composition better than text alone.
3. Run the same three briefs through Runway, Luma, and Kling AI. Use Pika for effect-led inserts.
4. Reject identity drift, object mutation, impossible motion, unreadable text, and continuity errors.
5. Cut accepted shots short, color-match them, design sound, and label synthetic footage when context requires it.

Cost control

Set an attempt ceiling per shot. If no model produces an acceptable result after that limit, use stock, animation, or a real shoot. Record accepted shots per credit and correction time; model reputation does not predict performance on your scene.

Never use generated b-roll as documentary evidence of a real person, place, product behavior, or event.

Sources & further reading

• Runway product
• Luma product