Vidu Q3 exposes a reference-to-video endpoint that lets an application guide a generated clip using supplied pictures of a person, object or scene.
The subject is a reference, not a locked rig
Its documentation differentiates Q3 series variants rather than treating every name as a synonym. The Q3 API text lists one to seven input images and notes that `viduq3-mix` does not currently support its subject-invocation method. That caveat should influence a choice between using raw image references and a stored subject library.
Choose the route for the story
A subject library is attractive when a particular product returns in many videos, but a single reference is often sufficient for a self-contained shot. Plan a furniture catalog clip with a front view, a three-quarter view and one close-up of the fabric. Verify the approved brand color, seam direction, screw positions and number of legs at the beginning and end. If the model introduces an incorrect decorative label, discard that shot or replace the label in compositing rather than calling the output fully faithful.
API inputs that matter
The provider describes duration and output settings as model-variant dependent; never assume a Q3 duration from a different Q series page. In its reference docs, image references accept common still formats with input size constraints, the prompt has a documented upper length, and some Q3 variants provide audio-reference options. A developer must validate a chosen exact model string, media payload size and authentication format from the route being called. Transferring an example for Q2 Pro or Q4 Preview without reviewing differences risks rejected jobs.
Sequence planning and evaluation
For a three-scene launch video, assign stable product references across the scenes but generate shots separately. The first shot establishes shape; the second demonstrates motion; the third shows a use case. Evaluate clips on continuity, physically plausible handling and reading order. Maintain both accepted and rejected samples with their settings so editorial staff can compare drift. Do not claim a quantified consistency score unless the team actually executes an independent protocol.
Consent, credits and uncertain details
Images of employees or customers need a clear license and purpose limitation. A documented image-reference feature does not establish rights to reproduce an identifiable person. Cost units, queue class, commercial rights, supported regions and export marks must be checked for the relevant account. Keep unsupported or changing values null rather than filling a matrix with assumptions.
Relevant alternatives and trade-offs
For a minimal historical integration inspect Vidu 2.0. For a preview model with broader reference/audio ambitions, inspect the separate Q4 Preview record, never mix both into one undated specification.