By Allen Zhao for MotifDeck. Prepared with AI assistance.
A background that looks good as a still image can feel distracting once the camera moves. One way to plan a layered 2D scene is to make a small, explicit parallax test before polishing the artwork.
Start with a simple model
For a single horizontal layer with no zoom or rotation, a basic screen position is:
screen_x = world_x - camera_x * parallax_factor Suppose an element starts at world x = 100 and the camera moves from x = 0 to x = 20. With a factor of 1 its screen position changes from 100 to 80; with 0.5 it changes from 100 to 90; with 0 it stays at 100. These are illustrative units and assume an otherwise stationary layer. Engines differ in coordinate and transform conventions, so use their documentation when implementing the equation.
Prepare the art for movement
Separate background, middle ground and foreground only where your project can actually edit or export them independently. Leave enough coverage beyond the initial viewport for the camera range you plan to test. Decide whether the layer should repeat or stop at an edge; a seamless repeat requires matching edges, not merely copying an image. Keep the original scene assets.
Preview at game speed
Move the camera slowly across the planned range, then repeat at normal gameplay speed. Watch for uncovered edges, distracting foreground motion, and important obstacles that become difficult to read. Use a fixed player marker to distinguish camera movement from character movement. If the game has camera zoom, camera shake or a moving layer, test those separately because the simple equation does not cover them.
Adjust deliberately
Try a few factors and record which layer each affects. A smaller background factor is one design choice, not a universal rule. Check both directions of travel and the final screen size before committing to an asset layout.
MotifDeck is an AI game-art workspace I work on; it supports creating game-art elements including scenes. The parallax calculation here is general game-development logic, not a claim of a built-in parallax editor.
