Shadows
Learn OpenGL: Shadow Mapping
Basic tutorial on shadow mapping
Experiments in Hybrid Raytraced Shadows
Explores combining rasterization and ray tracing for shadow rendering
Learn OpenGL guest article: Cascaded Shadow Mapping
Learn OpenGL guest article on cascaded shadow mapping, which resolves the resolution issues of the naive shadow mapping
Percentage-Closer Soft Shadows
NVIDIA paper introducing Percentage-Closer Soft Shadows (PCSS), based on shadow mapping and percentage‐closer filtering (PCF)
Using Blue Noise For Raytraced Soft Shadows
Article from the "blue noise guy" talking about how to apply blue noise to raytraced soft shadows
Efficient Shadows from Many Lights (2015)
Techniques for efficiently rendering shadows from many light sources in real-time