Ambient occlusion的意思
"Ambient Occlusion" is a term used in computer graphics and 3D rendering to describe the technique of calculating how much ambient light is blocked by surfaces and objects within a scene. Ambient occlusion is a global illumination effect that helps to add realism to rendered images by taking into account the shadows that are created where surfaces and objects meet.
Here's a breakdown of the terms:
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Ambient: In the context of computer graphics, "ambient" refers to the indirect, global lighting that illuminates a scene uniformly from all directions. This is in contrast to direct lighting, which comes from a specific source like a light bulb or the sun.
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Occlusion: "Occlusion" means blocking or hiding. In the context of ambient occlusion, it refers to the blocking of ambient light by objects and surfaces within a scene.
When ambient occlusion is applied to a 3D scene, it calculates the amount of ambient light that is blocked at each point on a surface. This is done by considering the surface's geometry and the presence of other objects nearby. Areas where the geometry is complex or where objects are closely packed together will receive less ambient light, and thus will appear darker. This helps to create more realistic shadows and crevices, adding depth and detail to the scene.
Ambient occlusion can be computed in various ways, from simple methods like ambient occlusion maps (pre-baked onto the surfaces of 3D models) to more complex and accurate real-time or offline rendering techniques that simulate global illumination more closely.
The effect of ambient occlusion is subtle but significant, as it can greatly enhance the realism and visual appeal of a rendered scene by adding a level of detail that would be difficult to achieve with traditional lighting models alone.