A fixed seed is not an archival copy of an approved AI video. It may make some generations more comparable when the model and other inputs stay the same, but it does not guarantee identical frames. Preserve the approved output file and its production record rather than relying on a future rerun to recreate a delivery.
Separate similar motion from exact reproduction
Runway's Gen-4 creation documentation describes fixed seeds as producing similar motion. The page also identifies Gen-4 as an older model. Neither statement establishes pixel-for-pixel reproducibility across service updates, model versions or other products.
A seed is only one part of a request. A different source crop, image revision, duration or prompt can change the task even when the seed number remains unchanged. Some workflows expose no seed at all; do not invent a hidden field or assume an API parameter exists because another provider documents one.
Keep a minimum reproduction record
For each approved shot, retain the exact source files, their orientation and dimensions, the submitted prompt, model identifier where visible, supported settings, date and resulting video. Record whether a reference was a starting image, a motion video or an audio source. A preview screenshot is useful for review, but it cannot replace the delivered media.
Where a private task identifier is available, save it in the project record without publishing user material. Keep an untouched copy of the accepted output and a separate working copy for editing. A file checksum can confirm that an archived file still matches that copy; it cannot prove that a regenerated clip has the same performance.
A hypothetical logo-introduction request
Suppose a client approves a short entrance shot and later requests a differently sized delivery. The producer has the final video, its original reference and the prompt. First determine whether the change can be made by reframing or encoding the accepted footage. If so, review the new crop and export rather than replacing the performance unnecessarily.
If a new generation is needed, compare it as a new candidate. Check the entrance timing, face, hand contact and final pose against the accepted clip. Similar camera movement is not enough if the client approved a particular gesture. This is a hypothetical decision process, not a claim that a particular seed reproduced a clip.
Decide what counts as a replacement
Accept approximate reproduction only when the brief permits a new performance and the reviewer approves its differences. Reject the assumption that an almost matching clip can silently replace an exact contractual delivery. If a service version has changed, document that uncertainty rather than repeatedly spending attempts on an unexplained mismatch.
For an Imagild project, archive completed assets while they are accessible and retain supported request details. Seed behavior from external documentation explains a general limit; it does not promise an Imagild seed control or indefinite regeneration access.
Sources
Prepared by Imagild Editorial with AI assistance and reviewed against the linked sources on October 13, 2026. Examples are hypothetical; external procedures do not establish Imagild features or guarantee results.