Syvyyspuskurit

Syvyyspuskurit, a Finnish term often translated as "depth buffers" or "z-buffers," are a fundamental component in computer graphics rendering, particularly in 3D graphics. Their primary function is to manage and resolve visibility issues, specifically determining which objects are in front of others when rendered onto a 2D screen.

In essence, a depth buffer is a 2D array, the same resolution as the display or render target, where each pixel stores a depth value. This depth value represents the distance of the corresponding pixel from the viewer's position along the viewing axis. During the rendering process, as each pixel of a 3D object is projected onto the 2D screen, its depth value is calculated. This calculated depth value is then compared to the depth value already stored in the depth buffer at that same pixel location.

If the new pixel's depth value is closer to the viewer than the value currently stored in the depth buffer, it means this new pixel is in front of whatever was previously rendered at that location. Therefore, the depth buffer is updated with the new, closer depth value, and the color information for this new pixel is written to the color buffer (which stores the final image). Conversely, if the new pixel's depth value is further away, it is considered occluded by something already rendered, and both its depth value and color information are discarded.

This depth testing process ensures that objects correctly overlap and that only the visible surfaces of 3D scenes are drawn to the screen, creating a realistic representation of depth and occlusion. Without depth buffering, objects rendered later would simply overwrite objects rendered earlier, regardless of their actual position in 3D space.