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How does screen space ambient occlusion work?
Screen Space Ambient Occlusion (SSAO) works by examining an onscreen pixel, and then comparing its location in a depth buffer to the pixels around it. To counter this, the SSAO pass is often blurred to remove such grain. As with traditional AO, SSAO is completely independent of the normal lighting system.
Is ambient occlusion post processing?
Ambient Occlusion is a post-processing effect that approximates crevice shadows in real time, darkening creases, holes, intersections, and surfaces that are close to each other.
How Ambient occlusion is calculated?
In most cases, ambient occlusion is calculated by constructing a hemisphere of rays emanating from a point on the surface in all directions and then checking them for the intersection with other objects.
How does screen space ambient occlusion work on a computer?
Screen-space ambient occlusion works more or less by looking for these “folds”—areas where the depth changes sharply, as defined by comparing the depths of neighboring pixels—and darkening them to simulate the decreased illumination from the points’ environment. Thanks for contributing an answer to Computer Graphics Stack Exchange!
How is ambient occlusion calculated in a pixel shader?
The algorithm is implemented as a pixel shader, analyzing the scene depth buffer which is stored in a texture. For every pixel on the screen, the pixel shader samples the depth values around the current pixel and tries to compute the amount of occlusion from each of the sampled points.
Are there any problems with ambient occlusion algorithms?
Though SSAO is an effective method, some problems can occur. Here is an example of insufficient shading. The tank bottom should be shaded because it should receive little light, but since the depth buffer has no information about the back face, the screen space effect does not obscure these areas.
Which is the first game to use ambient occlusion?
“Crysis,” released in the fall of 2007, is the first game on the CryEngine 2 game engine that used the ambient occlusion method called SSAO (Screen Space Ambient Occlusion). The screen space ambient occlusion method works as a post-effect, and it is calculated in the screen space. Today, this technology is used in all modern game engines.