Cinematic Ray Tracer

Description

For this showcase, I augmented the standard Ray Tracer to produce a “Cinematic” rendering effect. The goal was to move away from the perfect, sterile look of a pinhole camera and simulate a real-world camera lens.

Features Added:

1. Depth of Field (Defocus Blur)

   • Implementation: In main.cpp, I modified the ray generation logic. Instead of all rays originating from a single point (pinhole), I simulate a lens aperture. Rays are jittered on a disk around the camera origin (camera.e) and directed towards a focal point on the focal plane.
   • Effect: Objects at the focal distance remain sharp, while objects closer or further away become realistically blurry.

2. Anti-Aliasing (Super-Sampling)

   • Implementation: In main.cpp, I implemented a loop to cast multiple rays (50 samples) per pixel. Each ray’s screen coordinate is slightly jittered by a random amount. The final pixel color is the average of these samples.
   • Effect: This eliminates jagged edges (“jaggies”) on geometry and shadows, producing a much smoother, high-quality image.

3. Auto-Focus System

   • Implementation: In main.cpp, before the main render loop, I cast a single probe ray through the center of the screen to determine the distance to the nearest object.
   • Effect: This automatically sets the focal distance (t_focus) so the main subject of the scene is always in sharp focus without manual tuning.

Acknowledgements

• Base Code: CSC317 Course Material (Ray Tracing Assignment).
• External Libraries:
  • Eigen: For linear algebra operations.
  • nlohmann/json: For parsing scene files.
• Scene Data: sphere-packing.json from the course data folder.