Zbufferiin

Zbufferiin, commonly rendered as Z-buffering in English, is a fundamental technique in computer graphics for hidden surface removal during rasterization. It uses a per-pixel depth buffer to record the distance from the camera to the closest surface that has been drawn for each image pixel.

Originating in the 1970s with hardware-accelerated rasterizers, Z-buffering became a standard component of real-time 3D rendering. It complements polygon filling by ensuring that only the closest fragments contribute to the final color at each screen position.

During rendering, every visible polygon is rasterized. For each sample or pixel covered by the polygon, the depth value (z) is computed, often using perspective-correct interpolation. A depth test compares this value to the current entry in the depth buffer. If the new value is nearer, the color buffer is updated and the depth buffer is replaced; otherwise the fragment is discarded.

Implementation relies on a depth buffer (and usually a color buffer) of the same resolution as the output image. Depth precision and range must be chosen carefully to minimize artifacts, such as z-fighting when two surfaces have very similar depths. Transparent objects require additional techniques because Z-buffering handles opaque surfaces by default.

Variants and improvements include extended precision depth formats, hierarchical depth caching, and depth peeling for order-independent transparency. In modern GPUs, Z-buffering is a core component of the rendering pipeline and remains essential for real-time 3D graphics, graphics engines, and visualization tools.