Real-time Ray Tracing

• Physically based ray tracing / path tracing.
• GPU Compute workload implemented in CUDA.
• Real time rendering framework implemented with Vulkan.

Physically based rendering

• Monte Carlo uni-directional path tracing
• Surface BSDF models
• Rayleigh-Mie sky model
• Local light source

Acceleration

Variance reducing

• Low-discrepancy blue noise sampler
• Multiple importance sampling

Scene traversal

• LBVH
  • Two level BVH, each level with limited element count for better kernel efficiency
  • Triangle list -> AABB, morton codes, scene AABB
  • Radix sort -> Sorted morton codes, leaf reorder indices
  • LBVH build
  • BVH traversal using stack

Denoising

• SVGF `Atrous spatial + temporal filter

Optimizations

• Adaptive sampling/filtering with image noise level estimation
• Dynamic resolution

Post-processing

• Eye-adaptive histogram-based auto exposure
• Bloom effect
• Lens flare
• Tone mapping
• Sharpening

Prerequisites

• Windows 10 OS
• cmake 3.10
• CUDA
• Vulkan
• Git submodules
  • git clone --recurse-submodules
  • git submodule update --init --recursive
• Please note that it may have conflict with assimp NOMINMAX define

References

• Low-Discrepancy Sampler https://perso.liris.cnrs.fr/david.coeurjolly/publications/heitz19.html
• Edge-aware `Atrous https://jo.dreggn.org/home/2010_atrous.pdf
• LBVH http://graphics.snu.ac.kr/class/graphics2011/references/2007_lauterbach.pdf
• PLOC https://meistdan.github.io/publications/ploc/paper.pdf
• PBRT book and pbrt-v3 code.
• https://vulkan-tutorial.com/ and https://github.com/SaschaWillems/Vulkan for my simple vulkan implementation
• https://github.com/NVIDIA/cuda-samples for common cuda functions
• http://raytracey.blogspot.com/2015/10/gpu-path-tracing-tutorial-1-drawing.html The blog series are great
• https://www.shadertoy.com/ great place to learn cool ideas about rendering
• https://www.scratchapixel.com/ basic stuffs. well explained
• https://www.iquilezles.org/www/index.htm All solid fun stuffs
• https://developer.nvidia.com/blog/thinking-parallel-part-i-collision-detection-gpu/ LBVH explained
• https://developer.nvidia.com/gpugems/gpugems3/part-vi-gpu-computing/chapter-39-parallel-prefix-sum-scan-cuda
• HLBVH https://research.nvidia.com/sites/default/files/pubs/2010-06_HLBVH-Hierarchical-LBVH/HLBVH-final.pdf
• AAC http://graphics.cs.cmu.edu/projects/aac/
• https://alain.xyz/blog/ray-tracing-denoising great coverage of denoising