Unprojections Explained

Recently, one of the responses to the Reconstruction Positions […] post dealt with the unprojection of frustum corners. More specifically: with the inverted projection matrix and the final division with the coordinate. Being the lazy sod that I am on Sundays, I thought I’d quickly google it and paste a link¬†with the explanation. Only¬†one problem:…

Reconstructing positions from the depth buffer

Introduction [edit] To start things off more easily, I decided to limit this post to perspective projections and move on to the generalization (including orthographic projections) in a next blog post. When doing deferred shading or some post-processing effects, we’ll need the 3D position of the pixel we’re currently shading at some point. Rather than…

HBAO

An alternative implementation for HBAO

Introduction Image-space horizon-based ambient occlusion [HBAO] is a technique introduced by NVidia (Louis Bavoil et al.) in 2008. I recommend checking out the following resources to find out exactly how the algorithm works, this post will build on it further: ShaderX7 – Image-Space Horizon-Based Ambient Occlusion (by Louis Bavoil & Miguel Sainz) The original Siggraph…