Here are some ray tracing topics you can further learn about:
- More shapes
- Triangle
- Triangle mesh
- Disk
- Cylinder
- Cube
- Curve
- More lights
- Directional light
- Area light
- Objects as lights (eg. sphere light)
- Materials (dielectric/conductor)
- Soft shadows
- Displacement mapping
- Global illumination
- Path tracing
- Camera manipulation (move around)
- Animation
- Optimization and acceleration