Screen space ambient occlusion

[1] The algorithm is implemented as a pixel shader, analyzing the scene depth buffer which is stored in a texture.

Without additional smart solutions, such a brute force method would require about 200 texture reads per pixel for good visual quality.

In order to get high quality results with far fewer reads, sampling is performed using a randomly rotated kernel.

The kernel orientation is repeated every N screen pixels in order to have only high-frequency noise in the final picture.

Such a solution allows a reduction in the number of depth samples per pixel to about 16 or fewer while maintaining a high quality result, and allows the use of SSAO in soft real-time applications like computer games.