CPU Monte Carlo Path Tracer

A physically based, CPU-driven Monte Carlo Path Tracer built from scratch in C++. This project is a comprehensive implementation of advanced global illumination and ray tracing techniques, capable of rendering highly realistic scenes with complex light interactions.

✨ Core Features

• Monte Carlo Integration & PDF: Implements Importance Sampling (Cosine and Light source sampling) via Probability Density Functions (PDF) to drastically reduce noise and converge faster.
• BVH Acceleration: Uses Bounding Volume Hierarchies (bvh.h) for $O(\log N)$ ray-object intersection, enabling scenes with thousands of primitives.
• Advanced Materials:
  • Microfacet-like behaviors including Dielectrics (glass/refraction), Metals (with fuzziness), and Lambertian diffuse.
  • Emissive materials (lights) and Volumetric materials (constant medium/fog/smoke).
• Procedural & Image Textures: Support for solid colors, image-based mapping (stb_image), and procedural 3D Perlin noise (perlin.h).
• Geometry: Supports spheres, oriented quads (rectangles/boxes), and compound volumes.

🛠️ Build & Run

Prerequisites

• A modern C++17 compiler (GCC/Clang/MSVC)
• CMake (3.10+)

Compilation

mkdir build && cd build
cmake .. -DCMAKE_BUILD_TYPE=Release
make

Output

Run the executable and redirect the output to a .ppm file:

./PathTracer > image.ppm

📷 Gallery