meirbon / tracer

Path tracer with an advanced BVH, variance reduction & support for CPU & GPU

Tracer

A real-time ray/path tracing application.

Features

• Implements a cache-aligned BVH & 4-way MBVH with the following build methods: SAH, Binned SAH & Central split
• Dynamic objects with support for BVH-refitting and rebuilding (Only on CPU, for now...)
• Multithreaded CPU path/ray tracer & multithreaded BVH building
• Ray & path tracer on CPU
• OpenCL path tracer on GPU
• Sphere, plane, torus & triangles on CPU & triangles on GPU
• Variance reduction: Next Event Estimation & Multiple Importance Sampling
• Lambert Diffuse BRDF & Microfacet BRDF (GGX)

Screenshots

Building

Using CMake this project can be build on MacOS, Windows & Linux. All platforms have been successfully tested. For Linux Ubuntu 18.04 was used with a NVIDIA GTX 1080.

Dependencies

• GLEW
• SDL2
• OpenCL
• GLM
• FreeImage

Libraries have been included for Windows and CMake is configured to automatically link to the libs included in this repository. For Linux/Mac you should install GLEW, SDL2, FreeImage and (only on Linux) OpenCL libraries.

This project makes use of an OpenCL/OpenGL interop. Intel iGPUs do not support texture interop and therefor the OpenCL implementation in this project will not work on these GPUs.

Controls

Switching between the modes can be done using the following buttons:

• 1 for Reference (CPU + GPU)
• 2 for Next Event Estimation (NEE) (CPU)
• 3 for Importance Sampling (IS) (CPU)
• 4 for NEE + IS (CPU)
• 5 for NEE + Multiple IS (CPU + GPU)
• 6 for Reference + Microfacets (CPU + GPU)

The camera can be controlled using the mouse & WASD. View direction can also be changed using the arrow keys. The camera can be locked/unlocked by pressing L.

Planned features

• Play around with NVIDIA RTX (through OptiX)
• Port dynamic BVH to GPU
• More material types & improved microfacets
• Spatial BVH
• Implement Assimp model loader