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Ray-Tracing an Introduction - An Overview
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- 2. What We’ll DiscussToday • From rasterization to physically-based rendering. • Understanding light transport simulation. • Why this revolution matters for computer graphics. • What you need to know as future graphics engineers. • The mathematical and computational foundations. FACT: Ray tracing can simulate light behavior with near-physical accuracy
- 3. Recommend Reading 101 Ray-Tracing,Ray-Marching and Path-Tracing Projects (Paperback) Little Black Book of Ray-Tracing and Path-Tracing (Paperback) Learn how to ‘understand’ ray-tracing – but also how to build and improve ray-tracers – seeing the bigger picture (mathematics, hardware, applications, limitations, trade-offs, …) Graphics and Compute: Primer Volume 5 Ray- Tracing (Hardback) Ray-Tracing Pocket Book (Paperback) Quick introduction
- 4. The Graphics Revolution:Why Now? • Hardware acceleration finally caught up. • Consumer GPUs with dedicated RT cores. • Real-time performance becoming feasible. • Industry-wide adoption in games and film. • The end of approximation-based rendering? People Aren’t Happy They Want Better Graphics
- 5. What Exactly isRay Tracing? • Simulating the path of light through pixels. • Calculating intersections with scene geometry. • Modeling light-material interactions. • Solving the rendering equation numerically.
- 6. Ray Tracing vs.Rasterization • Rasterization: Project geometry to 2D. • Ray tracing: Simulate light from camera. • Different computational approaches. • Trade-offs between accuracy and speed. • Why both techniques still matter.
- 7. The Core Algorithm:A Single Ray's Journey • Camera generates primary rays. • Find closest intersection with scene. • Calculate lighting at intersection point. • Recursively spawn secondary rays. • Accumulate color contributions.
- 8. Key Mathematical Concepts •Vector geometry and linear algebra. • Ray-sphere/ray-plane intersections. • Barycentric coordinates. • Coordinate system transformations. • Probability and Monte Carlo methods.
- 9. The Rendering Equation •Kajiya's fundamental equation. • Describes light transport mathematically. • Accounts for emission, reflection, absorption. • The basis for all modern rendering techniques.
- 10. Why Ray TracingLooks More Realistic • Accurate shadows with penumbra. • Physically correct reflections. • Global illumination and indirect lighting. • Natural depth of field and motion blur. • Correct refraction and transparency.
- 11. The Computational Challenge •Millions of rays per frame. • Billions of intersection tests. • Exponential complexity with recursion. • Memory bandwidth limitations. STAT: A single 4K frame may require over 24 million primary rays
- 12. Acceleration Structures: BVH •Bounding Volume Hierarchies. • Reducing O(n) intersection tests to O(log n). • Spatial partitioning strategies. • Construction and traversal algorithms. • Hardware-accelerated BVH traversal.
- 13. Modern GPU Architecturefor Ray Tracing • Dedicated RT cores. • Hardware-accelerated intersection tests. • Parallel ray processing. • Memory hierarchy optimizations. • Hybrid rendering pipelines.
- 14. Real-Time vs. OfflineRay Tracing • Real-time: 30-60 fps, approximations. • Offline: Minutes to hours per frame, accuracy. • Different sampling strategies. • Quality vs. performance trade-offs.
- 15. Hybrid Rendering Approaches •Rasterization for primary visibility. • Ray tracing for specific effects. • Deferred shading with ray tracing. • Industry standard for real-time applications.
- 16. Key Ray TracingEffects: Shadows • Hard shadows vs. soft shadows. • Percentage closer filtering. • Area light sampling. • Contact shadows and occlusion.
- 17. Key Effects: Reflections •Perfect specular reflections. • Glossy reflections with roughness. • Screen space reflections limitations. • Ray traced reflections advantages.
- 18. Key Effects: GlobalIllumination • Indirect lighting simulation. • Color bleeding and ambient occlusion. • Photon mapping vs. path tracing. • Real-time GI approximations. BREAKTHROUGH: Real-time global illumination became practical with hardware RT
- 19. Sampling and NoiseReduction • Monte Carlo integration. • Importance sampling strategies. • Denoising algorithms. • Temporal accumulation. • AI-based denoising techniques.
- 20. Materials and BRDFs •Bidirectional Reflectance Distribution Functions. • Modeling surface appearance. • Diffuse, specular, metallic materials. • Energy conservation principles.
- 21. Texturing and RayTracing • UV mapping and procedural textures. • Texture filtering across rays. • Normal mapping and displacement. • Anisotropic texturing challenges.
- 22. Industry Standards: NVIDIARTX • Hardware and software ecosystem. • DirectX Raytracing (DXR) API. • Vulkan Ray Tracing extension. • OptiX for offline rendering. INDUSTRY SHIFT: 90% of AAA games now use some form of ray tracing
- 23. Programming Models andAPIs • DirectX Raytracing (DXR). • Vulkan Ray Tracing. • Metal Ray Tracing (Apple). • CUDA and OptiX for research.
- 24. Shader Types inRay Tracing Pipeline • Ray generation shaders. • Intersection shaders. • Any-hit and closest-hit shaders. • Miss shaders. • Callable shaders.
- 25. Performance Optimization Techniques •Ray coherence exploitation. • Early ray termination. • Adaptive sampling. • Memory layout optimizations. • Multi-level acceleration structures.
- 26. Common Implementation Challenges •Fireflies (high variance samples). • Memory management for acceleration structures. • Denoising artifacts. • Temporal stability issues. • Shader compilation overhead.
- 27. Ray Tracing inGame Development • Progressive adoption since 2018. • Performance budgeting strategies. • Scalability settings. • Art pipeline adaptations.
- 28. Ray Tracing inFilm and VFX • Pixar's RenderMan and path tracing. • Disney's Hyperion renderer. • Monte Carlo rendering for feature films. • Render farms and distributed rendering.
- 29. Ray Tracing inScientific Visualization • Volume rendering for medical imaging. • Molecular visualization. • Fluid dynamics simulation. • Astrophysics and cosmological simulations.
- 30. Emerging Applications: AR/VR •Mixed reality with realistic lighting. • Real-time ray tracing for passthrough AR. • Challenges for mobile and standalone VR. • Foveated rendering with eye tracking.
- 31. Future Directions: NeuralRendering • Neural radiance fields (NeRF). • Combining ray tracing with machine learning. • Neural denoising and super-resolution. • Generative models for scene completion.
- 32. Future Directions: HardwareEvolution • Specialized ray tracing processors. • Photonic computing for light simulation. • In-memory processing architectures. • Quantum computing potential.
- 33. Educational Resources andTools • NVIDIA's OptiX SDK. • Intel's Embree library. • Blender Cycles renderer. • Educational ray tracing frameworks.
- 34. Prerequisite Knowledge forThis Course • Linear algebra and vector calculus. • C++ programming experience. • Basic computer graphics concepts. • GPU architecture fundamentals. • Multivariable calculus and probability.
- 35. Course Structure andExpectations • Theory lectures and practical implementations. • Weekly programming assignments. • Final project: simple ray tracer. • Performance optimization challenge. • Research paper presentation.
- 36. Career Opportunities inRay Tracing • Graphics engineer at game studios. • R&D engineer at GPU companies. • VFX and animation technical director. • AR/VR rendering engineer. • Research scientist in academia.
- 37. Ethical Considerations • Environmentalimpact of rendering. • Deepfakes and synthetic media. • Accessibility of advanced graphics. • Digital divide in graphics technology.
- 38. Common Misconceptions AboutRay Tracing • It's not just for reflections. • It doesn't always mean photorealistic. • It's not necessarily slower than rasterization. • It doesn't replace all other rendering techniques. MYTH: Ray tracing is only for Hollywood and AAA games
- 39. Getting Started: SimpleRay Tracer • Start with spheres and planes. • Implement basic intersection tests. • Add simple shading models. • Progress to triangles and meshes. • Implement acceleration structures.
- 40. Debugging Ray TracingPrograms • Visualize ray paths and intersections. • Use heatmaps for performance analysis. • Implement validation layers. • Test with simple reference scenes.
- 41. The Beauty ofRay Tracing Mathematics • Elegant intersection algorithms. • Geometric transformations. • Probability density functions. • Numerical integration methods. • Optimization theory applications.
- 42. Why This KnowledgeMatters • Foundation for future graphics innovation. • Transferable skills to other domains. • Understanding of physical light transport. • Preparation for industry trends. • Development of mathematical intuition.
- 43. Recommend Reading 101 Ray-Tracing,Ray-Marching and Path-Tracing Projects (Paperback) Little Black Book of Ray-Tracing and Path-Tracing (Paperback) Learn how to ‘understand’ ray-tracing – but also how to build and improve ray-tracers – seeing the bigger picture (mathematics, hardware, applications, limitations, trade-offs, …) Graphics and Compute: Primer Volume 5 Ray- Tracing (Hardback) Ray-Tracing Pocket Book (Paperback) Quick introduction
- 44. Questions and Discussion •What excites you about ray tracing? • What challenges do you anticipate? • How might this technology evolve? • What applications interest you most?