CRITICALFailure Reference

Seedance Physics Collapse — Pre-Generation Risk Reference

Technical Classification

Physical Plausibility & Momentum Coherence Failure

Seedance 1 Pro's diffusion model has no explicit physics simulation; physical behaviour is learned statistically from training video and breaks under unfamiliar scene compositions. The most common failures are gravity inversion (objects floating mid-clip), momentum collapse (motion stopping or reversing without contact), and fluid behaviour failures (water moving against gravity or in non-Newtonian patterns). The failure makes the output unusable for any technical or commercial context.

How to identify this failure

✕Object floating without support mid-clip
✕Water flowing uphill or hanging in air
✕Vehicle motion stopping without contact
✕Falling object accelerating in the wrong direction
✕Smoke or hair moving in a way inconsistent with the apparent wind direction

Real generation examples

Prompt used

"Glass of water tipping over on a wooden table"

Failure observed @ 0:02

Water exited the glass and pooled in mid-air at 0:02; glass returned upright with no spill

Prompt used

"Bicycle rolling down a steep hill"

Failure observed @ 0:04

Bicycle decelerated then began rolling uphill at 0:04 without external force

Documentation strength

If you need to escalate

VERY HIGH — physics failures are unambiguously refundable; Seedance support treats them as a recognised critical mode.

AVA is a pre-purchase prevention tool, not a post-purchase recovery tool. Platforms generally do not guarantee credit refunds for output-quality failures; goodwill credits are at each platform's discretion. The strength rating reflects how well-formed your support ticket can be, not a promised outcome.

Prevention + documentation steps

01
Score your prompt before you generate
Run your prompt through AVA's pre-flight scoring against the Physical Plausibility & Momentum Coherence Failure pattern. Green light = generate. Yellow/red = rewrite using the suggested fix before you commit credits.
02
Capture Generation ID + timestamp if it failed anyway
Find the Generation ID in the URL or share link. Note the exact time when the Physical Plausibility & Momentum Coherence Failure first appears (e.g. "failure first visible at 1.2s"). Timestamped evidence is significantly stronger than a general complaint.
03
Use the correct technical term in your support ticket
Describe this failure as "Physical Plausibility & Momentum Coherence Failure". This term maps to a recognised internal workflow in the support system and routes the ticket to the right team.
04
Submit via the correct support channel
Runway has no direct email intake. Pro+ plan: open the in-app AI Assistant (help widget bottom-right of app.runwayml.com), describe the failure with the technical term, attach evidence. Free/Standard plan: human support isn't available — your channel is Discord #community-help with @On Call - Moderators.

Frequently asked questions

Does Seedance refund credits for physics failures?

Yes. Submit the generation ID, a description using the term "Physical Plausibility & Momentum Coherence Failure", and a timestamped failure point. Refunds are routinely approved.

Why does Seedance generate impossible physics?

Seedance's diffusion model learns physical behaviour statistically from training videos rather than running an explicit physics simulation. Under unfamiliar scene compositions the statistical priors fail and gravity/momentum/fluid behaviour breaks.

Which Seedance prompts are highest risk for physics failures?

Fluid dynamics (water, oil, smoke), gravity-driven motion (falling objects, rolling vehicles), and complex object interactions. AVA pre-flags these and suggests safer alternatives.

Score your prompt

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Paste your prompt and the platform you intend to use. AVA returns a red/yellow/green score against this specific failure mode plus a concrete rewrite if the risk is high.

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