How to make an object change over the length of a clip
Describe both ends to Vizard Agent: what the object is at the start and what it has become by the end. It generates the two states in the same frame so the lighting and background match, isolates each as a layer, and animates between them across the clip's own duration.
What do you type into Vizard Agent?
Describe the end state as a picture rather than as a process. "Rots" is a verb with an enormous range, whereas "brown, shrivelled and sunken by the final frame" tells Vizard Agent exactly where the animation has to arrive by the time the clip ends. Say how the change should be paced and what has to stay untouched.
Prompt
What does Vizard Agent actually do?
This is a replacement plus a timeline. Vizard Agent builds both ends as a pair in the same frame, so the only difference between them is the thing that is supposed to change. Generated separately, they would come back with different lighting, different shadows and different positions. In the session behind this article it:
- Checked the clip's duration and dimensions, and inspected the cup closely in the first and last frames.
- Measured the cup's exact position, checked the display orientation, and widened the crop to include the surface under the cup, because a replacement without its own shadow reads as a sticker.
- Generated a fresh apple and a rotting apple in the same frame, in parallel, and checked each for fidelity to the original background.
- Isolated both apples as transparent layers and fixed the replacement mask so the cup's edges disappeared without leaving a halo.
- Built an animation layer moving gradually from fresh to rotten and composited it over the clip, keeping the original soundtrack.
When does this not work well?
Some shots cannot hold a state change. If the object is handled, moves behind something, or the camera moves around it, the two-state approach has to become full tracking, and every frame between the states has to hold up on its own. Very long clips need building in stages, and a reflective surface keeps the old object in its reflection.
Common questions
Can it go the other way, rotten to fresh? Yes. Vizard Agent treats it as the same job with the states reversed.
Does the camera have to be still? It is much easier. With a moving camera, Vizard Agent has to track as well as animate.
Can it keep the original audio? Yes. Vizard Agent composites the picture and leaves the sound alone.