Parallax backgrounds

Produce a stack that remains convincing while layers move independently. Correctness belongs to the moving composite, not just the resting image.

Hidden is not transparent

Each layer needs its own complete shape, not merely the pixels visible through the layers in front of it.

• The farthest plate is ordinarily opaque throughout the sampled region. Remove nearer objects and reconstruct the scenery they covered.
• A middle layer contains its complete objects, including portions hidden by foreground objects. Alpha reveals farther scenery only where this middle plane has no material. Do not punch foreground-shaped holes into it.
• A foreground layer contains its objects and genuine openings, with transparency elsewhere. Continue cropped branches, trunks, terrain, and other forms beyond the initial viewport wherever movement can expose them.
• Nearer objects belong only on their assigned plane. Do not leave duplicate silhouettes, recognizable outlines, or inappropriate shadow residue baked into rear plates.
• Use fractional alpha for genuinely translucent material and antialiased edges. Keep opaque objects opaque; lowering a whole layer's opacity does not replace a correct cutout mask.

Example: sky → mountains → trees. Sky continues behind both mountains and trees. Mountains continue behind trees, with transparency above their own skyline. Trees reveal mountains/sky through branch gaps. Tree silhouettes must not be cut out of the mountain plane.

Establish the image and motion contract

Infer from the request/project and state assumptions; ask only for consequential missing choices: