What is back-face culling?

Back-face culling is a technique used in computer graphics to determine whether to display or discard the faces of a 3D object that are not visible to the viewer.

In 3D modeling, objects are made up of polygons with front and back faces. Back-face culling involves calculating which faces are facing away from the viewer and should not be visible. This is typically done using the normals of the polygons, which indicate the direction that the face is pointing.

If the back-facing polygons are not visible, they can be discarded, which can improve performance and reduce computational load. This is particularly useful in real-time rendering, where speed and efficiency are important.

Back-face culling can be applied at different levels of the rendering pipeline, from the application level to the hardware level. It is often used in conjunction with other techniques such as z-buffering, depth sorting, and occlusion culling to create efficient and visually appealing 3D graphics.