Using multisample anti-aliasing
Anti-aliasing is the technique of removing or reducing the visual impact of aliasing artifacts that are present whenever high-resolution or continuous information, is presented at a lower resolution. In real-time graphics, aliasing often reveals itself in the jagged appearance of polygon edges, or the visual distortion of textures that have a high degree of variation.
The following images show an example of aliasing artifacts at the edge of an object. On the left, we see that the edge appears jagged. This occurs because each pixel is determined to lie either completely inside the polygon, or completely outside it. If the pixel is determined to be inside, it is shaded, otherwise it is not. Of course, this is not entirely accurate. Some pixels lie directly on the edge of the polygon. Some of the screen area that the pixel encompasses actually lies within the polygon and some lies outside. Better results could be achieved if we were to modify the shading of a...