CUDA Path Tracer

Features

• Wavefront Path Tracing

  • Separating mega-kernels into several kernels: RayGen, Intersection, Shade ...
  • Less Warp Divergence: Stream compacting the ray path segments
  • Improve Memory Access Coalescing: SoA data layout and sorting path segments by material type before shading

• Texture Mapping: More surface color based on CUDA Texture Object

• Triangle Primitive Mesh: More shapes based on Obj loader

• Accelerate Data Structure BVH:

  • Binary Radix Tree Construction
  • Parallel Tree Traversal
  • Two Level Acceleration Structures: world level (TLAS) & model level (BLAS)

• Efficient Monte Carlo Integrator:

  • Next Event Estimation: Shadow rays are explicitly aimed at light sources
  • Multiple Importance Sampling: Combining the PDFs of different sampling techniques

• Physically Based Rendering:

  • Diffuse (Lambertian)
  • Dielectric
  • Conductor
  • Plastic

  Kulla Conty approximation for multi-scattering is implemented for Dielectrics and Conductors

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TODO:

• Denoiser

• Material BSDF Data Structure

• Global Queue

Screenshots

Dependencies

• CUDA
• OpenGL
• GLFW
• GLEW
• GLM
• ImGui
• Stb Image
• Tinyobj loader
• nlohmann-json

Reference

• CIS 5650 GPU Programming and Architecture
• Physically Based Rendering V4
• GPU-Raytracer (Open Source Code)