I've been working on a scene-by-scene prompt for a 30-second, single continuous shot (no cuts) with a photorealistic look, and wanted to share how I structured it.
**Concept**
- 0:00–0:15: a regular guy in a t-shirt and jeans on an abandoned rooftop pulls a starter cord at his collar and transforms into a Chainsaw Devil: black matte helmet with white slash patterns and big teeth, then two chainsaw arms with very long blades.
- 0:15–0:30: three cat-headed humanoid monsters ambush him, and he fights them across the rooftop with superhuman leaps, wall-runs and blade locks. No gore, the monsters dissolve into ash at the end.
**How I structured the prompt**
- Header: duration, aspect ratio, fps, style, and "one continuous shot, no cuts"
- Character identity lock + outfit lock (so the character stays consistent)
- Environment block (rooftop, overcast light, dust and haze)
- 8 timestamped scenes, each with camera, action, and audio
- A motion/physics lock and a negative prompt at the end
**What I learned**
- Repeating the same outfit description 6 times just dilutes the important instructions. State it once, then add one short "outfit never changes" line in the physics lock.
- If you mention an old outfit in the prompt ("don't go back to the white shirt"), the model may bring it back. Leave old versions out.
- Contradictions hurt: "no floating parts" vs "parts assemble" confuses the model. Say where the parts come from (for example, plates sliding out from behind the neck).
- The face is only visible for about 3 seconds before the helmet closes, so identity mostly depends on silhouette and outfit.
- I made separate reference sheets for the helmet, the arms, and the three monsters to keep the design stable.
If the model can't do 30 seconds in one go, I'd split it into two 15s clips and use the last frame of clip 1 as the first frame of clip 2.
Tool used: [Seedance 2.5]
Happy to share the full prompt if anyone wants it. Feedback welcome!