Books and Tutorials

• Parent: PathTracer Learning

Essential Books

• “Ray Tracing in One Weekend” series — Peter Shirley (free online)
  • Book 1: Ray Tracing in One Weekend — basic ray tracer
  • Book 2: Ray Tracing: The Next Week — BVH, textures, motion blur
  • Book 3: Ray Tracing: The Rest of Your Life — Monte Carlo, importance sampling
  • URL: https://raytracing.github.io/
  • Best starting point — builds intuition before GPU
• “Physically Based Rendering: From Theory to Implementation” (PBRT)
  • Pharr, Jakob, Humphreys — the definitive reference
  • 4th edition free online: https://pbr-book.org/
  • Covers everything: BVH, BRDFs, Monte Carlo, spectral rendering, volumes
  • Very dense — use as reference, not cover-to-cover
  • Chapter 9 (Reflection Models) and Chapter 13 (Monte Carlo) are essential
• “Real-Time Rendering” — Akenine-Möller et al.
  • Chapter 26: Real-Time Ray Tracing
  • Good overview of hardware RT and denoising
• “Fundamentals of Computer Graphics” — Shirley & Marschner
  • Good intro to the math before diving into PBRT

Vulkan Ray Tracing

• Vulkan Ray Tracing Tutorial — NVIDIA (nvpro-samples)
  • https://github.com/nvpro-samples/vk_raytracing_tutorial_KHR
  • Step-by-step from basic triangle to full path tracer
  • Uses C++ + GLSL, very practical
• Vulkan Specification — Ray Tracing chapters
  • https://registry.khronos.org/vulkan/specs/1.3-extensions/html/
  • Chapters on VK_KHR_ray_tracing_pipeline, VK_KHR_acceleration_structure
• “Ray Tracing Gems” (free PDF)
  • https://www.realtimerendering.com/raytracinggems/
  • Collection of practical techniques from industry experts
  • Chapter 3: Introduction to DirectX Raytracing (concepts apply to Vulkan)
  • Chapter 20: Texture Level of Detail Strategies for Real-Time Ray Tracing
• “Ray Tracing Gems II” (free PDF)
  • https://www.realtimerendering.com/raytracinggems/rtg2/
  • More advanced topics: ReSTIR, denoising, production techniques
  • Chapter 23: ReSTIR GI

Key Papers

• Kajiya 1986 — “The Rendering Equation”
  • Foundation of physically-based rendering
• Möller & Trumbore 1997 — “Fast, Minimum Storage Ray/Triangle Intersection”
  • The standard ray-triangle intersection algorithm
• Walter et al. 2007 — “Microfacet Models for Refraction through Rough Surfaces”
  • GGX BRDF derivation
• Heitz 2014 — “Understanding the Masking-Shadowing Function in Microfacet-Based BRDFs”
  • Definitive reference for Smith G term
• Heitz 2018 — “Sampling the GGX Distribution of Visible Normals”
  • VNDF sampling — better importance sampling for GGX
• Burley 2012 — “Physically-Based Shading at Disney”
  • Disney Principled BRDF — the basis for most PBR workflows
• Veach & Guibas 1995 — “Optimally Combining Sampling Techniques for Monte Carlo Rendering”
  • MIS (Multiple Importance Sampling) — essential for path tracing
• Bitterli et al. 2020 — “Spatiotemporal reservoir resampling for real-time ray tracing with dynamic direct lighting”
  • ReSTIR DI paper
• Ouyang et al. 2021 — “ReSTIR GI: Path Resampling for Real-Time Path Tracing”
  • ReSTIR GI paper
• Schied et al. 2017 — “Spatiotemporal Variance-Guided Filtering”
  • SVGF denoiser
• Müller et al. 2017 — “Practical Path Guiding for Efficient Light-Transport Simulation”
  • SD-Tree path guiding
• Woop et al. 2013 — “Watertight Ray/Triangle Intersection”
  • Prevents light leaking through mesh cracks

Video Courses

• “Computer Graphics” — TU Wien (YouTube, free)
  • Excellent lectures on rendering theory
  • Covers path tracing, BRDFs, Monte Carlo in depth
  • https://www.youtube.com/playlist?list=PLujxSBD-JXgnGmsn7gEyN28P1DnRZG7qi
• “Advances in Real-Time Rendering” — SIGGRAPH courses
  • Annual course with cutting-edge techniques
  • https://advances.realtimerendering.com/
• “Introduction to Computer Graphics” — Cem Yuksel (YouTube)
  • Clear explanations of rendering fundamentals
• “GAMES101” — Lingqi Yan (YouTube, Chinese with subtitles)
  • Comprehensive graphics course, excellent path tracing coverage

Online Resources

• Shadertoy — https://www.shadertoy.com/
  • Many path tracer implementations to study
  • Search “path tracer” for examples
• Inigo Quilez’s articles — https://iquilezles.org/articles/
  • Excellent math and rendering articles
• Physically Based Rendering blog — https://www.pbr-book.org/blog
• JCGT (Journal of Computer Graphics Techniques) — https://jcgt.org/
  • Free peer-reviewed graphics papers

Godot Specific

• Godot source code — servers/rendering/renderer_rd/
  • Best documentation is the code itself
• NVPathtracer PR/fork — study the actual implementation
• Godot rendering documentation
  • https://docs.godotengine.org/en/stable/contributing/development/core_and_modules/custom_rendering_server.html
• Godot RenderingDevice API docs
  • https://docs.godotengine.org/en/stable/classes/class_renderingdevice.html