1
I only have an idea
Use the text route. Write one sentence describing the subject, movement, setting, camera feel, and approximate mood. For example: “A red kite rises above a windy beach as the camera follows it.” If you are researching how to use vidu ai on iphone, this is the cleanest first test because there is no image to crop or upload.
2
I already have a photo
Use the image route. Pick a clear photo from Photos, check that the subject is visible near the center, and describe the motion you want added. Ask for movement that fits the source image rather than trying to change every visual detail at once.
3
I need a repeatable character or object
Use a reference-based route when identity and appearance matter across the clip. Gather one or more useful reference images first, then specify the action and setting separately so the system has fewer competing instructions.