Guide · Block or Build

Step 1: the blockout

You lay out the shot in Blender, record the viewport (the playblast) and a video model paints the final picture over it. This guide covers what to put in that blockout, and how to check what comes back.

The rule

The model copies the blockout: its shapes and its motion. A copied shape is what you want. A copied motion is only as good as its keys, and usually looks mechanical.

1. Build the shapes.Products, named props and set pieces seen close: model them, so the model copies the exact design.
2. Block the motion.People and animals: a capsule with no legs, so the model invents the gait. A rig's motion is copied as it is: worth it only with a clean cycle of the exact motion.
3. Hybrid, for most shots.Build the set and some props, block the characters and other elements.

1. Characters and creatures: block them

1. A capsule at true height.A ball head on top. For a creature, a horizontal body at its length.
2. Two or three features that tell them apart.Hair, a hood, a backpack; for a creature, snout, ears, tail. Two capsules that differ only in color can swap identities.
3. No legs.Frozen legs slide. A rigged walk cycle slid in The Last Lantern, and a wolf's walk sped up came back as a fast walk. A clean biped run cycle was copied well: rig only when you have the exact motion.
4. Key the path, nothing more.Position and heading, at the real pace. The model adds the steps.
5. Arms only when a hand-off matters.Two capsules with arms gave the same kneel and hand-off as posed mannequins. Leave them off a runner: still arms came back hanging low.

2. Props and set pieces: build what must look exact

1. Build products and named props.A block gives the model a size to fill: blocked braziers vanished in two takes and became planters in another.
2. Build set pieces the camera passes close.Generate each from a concept image, place it at its block and fit it to the block's visible height.
3. Block the far set and the filler.One flat color per kind and one legend sentence in the prompt: "the cones on brown posts are pines".
4. Avoid shapes that can be misread.A disc under a turtle came back as a fifth flipper; a yellow lamp post as a second lantern.

3. Scale, camera and still

1. Real sizes.Meters in Blender. The model keeps where things are and how big they are.
2. One camera move, locked.Playblast from the shot camera, in flat colors.
3. The still from the blockout's first frame.Same framing, so the look lands on the right shapes. Any exact design goes in the still too.

4. The prompt

One sentence says what the stand-ins are and what they mark. "Only marks" leaves the design and the gait to the model.

Character, blockedIn @video1 the girl is a plain red stand-in shape with no legs: it only marks where she is, her height and her direction; replace it with the real girl from @image1. She runs naturally at a steady pace: knees driving forward, feet striking the dirt under her hips and pushing off, never sliding.

Creature, blockedIn @video1 the wolf is a plain blue-gray stand-in shape with no legs: it only marks where the wolf is, its size and its direction; replace it with the real wolf from @image1. It runs in a loose, natural gallop: front legs reaching far forward, hind legs gathering under the body, paws striking the dirt and never sliding.

Prop, builtIn @video1 the sneaker is a 3D model of the real shoe in its two colors: keep its exact shape on every side.

5. Run the takes

1. Reference mode.Seedance 2.5: the playblast as @video1, the still as @image1, nothing else.
2. Draft first.480p drafts, then finish the keepers at 1080p.
3. Re-roll before you change the setup.The same inputs can give a different take.

6. Review: what to check

What these tests cannot tell you

Each variant shows one or a few takes: observations, not rates. All tests used one model, Seedance 2.5, in reference mode. Run your own A/B with the skill before committing a production.

Download the Scenario MCP skill See the six examples