- Screen Space Ambient Occlusion (SSAO), see also SSAOShader.js
- http://john-chapman-graphics.blogspot.com/2013/01/ssao-tutorial.html
- https://learnopengl.com/Advanced-Lighting/SSAO
- https://creativecoding.soe.ucsc.edu/courses/cmpm164/_schedule/AmbientOcclusion.pdf
- https://github.com/McNopper/OpenGL/blob/master/Example28/shader/ssao.frag.glsl
- https://drive.google.com/file/d/1SyagcEVplIm2KkRD3WQYSO9O0Iyi1hfy/edit
- Scalable Ambient Occlusion (SAO), see also SAOShader.js
- N8HO
- Horizon Based Ambient Occlusion (HBAO)
- http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.577.2286&rep=rep1&type=pdf
- https://www.derschmale.com/2013/12/20/an-alternative-implementation-for-hbao-2/
- https://github.com/scanberg/hbao/blob/master/resources/shaders/hbao_frag.glsl
- https://github.com/nvpro-samples/gl_ssao/blob/master/hbao.frag.glsl
- GTAO
- further reading
- https://ceur-ws.org/Vol-3027/paper5.pdf
- https://www.comp.nus.edu.sg/~lowkl/publications/mssao_visual_computer_2012.pdf
- https://web.ics.purdue.edu/~tmcgraw/papers/mcgraw-ao-2008.pdf
- https://www.activision.com/cdn/research/Practical_Real_Time_Strategies_for_Accurate_Indirect_Occlusion_NEW%20VERSION_COLOR.pdf
- https://patapom.com/blog/SHPortal/
- https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.390.2463&rep=rep1&type=pdf
- https://www.intel.com/content/www/us/en/developer/articles/technical/adaptive-screen-space-ambient-occlusion.html
- https://github.com/GameTechDev/ASSAO