Further reading
Global illumination is an incredibly big topic that’s covered extensively in all rendering literature, but we wanted to highlight links that are more connected to the implementation of DDGI.
DDGI itself is an idea that mostly came from a team at Nvidia in 2017, with the central ideas described at https://morgan3d.github.io/articles/2019-04-01-ddgi/index.html.
The original articles on DDGI and its evolution are as follows. They also contain supplemental code that was incredibly helpful in implementing the technique:
- https://casual-effects.com/research/McGuire2017LightField/index.html
- https://www.jcgt.org/published/0008/02/01/
- https://jcgt.org/published/0010/02/01/
The following is a great overview of DDGI with Spherical Harmonics support, and the only diagram to copy the border pixels for bilinear interpolation. It also describes other interesting topics: https://handmade.network/p/75/monter/blog/p/7288-engine_work__global_illumination_with_irradiance_probes...