quasi3D

Quasi3D is a term used in computer graphics and digital media to describe approaches that create the impression of three-dimensional space without employing a full, interactive 3D model pipeline. This category covers methods that rely on two-dimensional assets, simplified geometry, and depth cues to convey depth and perspective.

Techniques include isometric or oblique projection, parallax scrolling, and billboarded sprites; ray casting or voxel-like rendering that approximates 3D from 2D data; and 2.5D representations where a scene has depth layers but limited true 3D movement. The goal is to achieve a convincing sense of depth while keeping rendering costs low.

Quasi-3D has been used in early video games, mobile apps, and visualization tools where performance constraints or design choices favor speed over full 3D realism. It is also used for stylistic effects, retro aesthetics, and rapid prototyping of spatial concepts.

Limitations include restricted camera freedom, simplified occlusion and lighting, and difficulty scaling to complex scenes. While modern engines favor true 3D, quasi-3D techniques remain relevant for lightweight experiences and certain visual goals.

Related concepts include 2.5D, pseudo-3D, isometric graphics, and parallax scrolling.