Book Image

3D Graphics Rendering Cookbook

By : Sergey Kosarevsky, Viktor Latypov
4 (2)
Book Image

3D Graphics Rendering Cookbook

4 (2)
By: Sergey Kosarevsky, Viktor Latypov

Overview of this book

OpenGL is a popular cross-language, cross-platform application programming interface (API) used for rendering 2D and 3D graphics, while Vulkan is a low-overhead, cross-platform 3D graphics API that targets high-performance applications. 3D Graphics Rendering Cookbook helps you learn about modern graphics rendering algorithms and techniques using C++ programming along with OpenGL and Vulkan APIs. The book begins by setting up a development environment and takes you through the steps involved in building a 3D rendering engine with the help of basic, yet self-contained, recipes. Each recipe will enable you to incrementally add features to your codebase and show you how to integrate different 3D rendering techniques and algorithms into one large project. You'll also get to grips with core techniques such as physically based rendering, image-based rendering, and CPU/GPU geometry culling, to name a few. As you advance, you'll explore common techniques and solutions that will help you to work with large datasets for 2D and 3D rendering. Finally, you'll discover how to apply optimization techniques to build performant and feature-rich graphics applications. By the end of this 3D rendering book, you'll have gained an improved understanding of best practices used in modern graphics APIs and be able to create fast and versatile 3D rendering frameworks.
Table of Contents (12 chapters)

Precomputing BRDF LUTs

In the previous recipes, we learned how to initialize compute pipelines in Vulkan and demonstrated the basic functionality of compute shaders. Let's switch gears back to PBR and learn how to precompute the Smith GGX BRDF LUT. To render a PBR image, we have to evaluate the BRDF at each point based on surface properties and viewing direction. This is computationally expensive, and many real-time implementations, including the reference glTF-Sample-Viewer implementation from Khronos, use precalculated tables of some sort to find the BRDF value based on surface roughness and viewing direction. A BRDF LUT can be stored as a 2D texture where the x axis corresponds to the dot product between the surface normal vector and the viewing direction, and the y axis corresponds to the 0...1. surface roughness. Each texel stores two 16-bit floating-point values—namely, a scale and bias to F0, which is the specular reflectance at normal incidence.

Important note...