Path Tracing Demo

This demo implements a Monte Carlo Path Tracing technique using hardware accelerated ray tracing support in Unity. There is no rasterization based rendering in the demo and a render pipeline is not used (the Camera doesn't render any geometry).

Prerequisites

• Windows 10 version 1809 and above.
• Any NVIDIA GPU starting from GTX 1060 with 6 GB of VRAM. AMD 6000 series GPUs based on RDNA 2 architecture might also run the demo but were not tested.
• Unity 2020.2 and above.

Recommendations

• Use winver in a command prompt to see exactly which Windows version you are using.
• NVIDIA GPUs from RTX 2000 series and above are recommended because they have hardware units dedicated to ray tracing. A GTX 1060 GPU was 10 to 15 times slower in tests because ray tracing support is emulated and runs entirely on compute units.
• Alternatively use a tool like GPU-Z to check if your system supports ray tracing. The demo will print an error in the console window if ray tracing is not supported.

Setup and Interaction

When in Play Mode, hold right mouse button down and use WASD keys to navigate through the scene. Convergence is reset when the view changes.

Acknowledgements

Alan Wolfe (@Atrix256 on Twitter) for his blog about computer graphics. The demo was inspired by the series of 3 blog posts:

https://blog.demofox.org/2020/05/25/casual-shadertoy-path-tracing-1-basic-camera-diffuse-emissive/ https://blog.demofox.org/2020/06/06/casual-shadertoy-path-tracing-2-image-improvement-and-glossy-reflections/ https://blog.demofox.org/2020/06/14/casual-shadertoy-path-tracing-3-fresnel-rough-refraction-absorption-orbit-camera/