Ray Tracing Gems

This book is a must-have for anyone serious about rendering in real time. With the announcement of new ray tracing APIs and hardware to support them, developers can easily create real-time applications with ray tracing as a core component. As ray tracing on the GPU becomes faster, it will play a more central role in real-time rendering. Ray Tracing Gems provides key building blocks for developers of games, architectural applications, visualizations, and more. Experts in rendering share their knowledge by explaining everything from nitty-gritty techniques that will improve any ray tracer to mastery of the new capabilities of current and future hardware. What you'll learn: The latest ray tracing techniques for developing real-time applications in multiple domains Guidance, advice, and best practices for rendering applications with Microsoft DirectX Raytracing (DXR) How to implement high-performance graphics for interactive visualizations, games, simulations, and more Who this book is for: Developers who are looking to leverage the latest APIs and GPU technology for real-time rendering and ray tracing Students looking to learn about best practices in these areas Enthusiasts who want to understand and experiment with their new GPU

An approximation to multiple scattering in volumetric illumination towards real-time rendering

Many volumetric illumination techniques for volume rendering were developed through out the years. However, there are still many constraints regarding the computation of multiple scattering path tracing in real-time applications due to its natural complexity and scale. Path tracing with multiple scattering support can produce physically correct results but suffers from noise and low convergence rates. This work proposes a new real-time algorithm to approximate multiple scattering, usually only available in offline rendering production, to real-time. Our approach explores the human perceptual system to speed up computation. Given two images, we use a CIE metric stating that the two will be perceived as similar to the human eye if the Euclidean distance between the two images in CIELAB color space is smaller than 2.3. Hence, we use this premise to guide our in vestigations when changing ray and bounce parameters in our renderer. Our results show that we can reduce from 105 to 104 Samples Per Pixel (SPP) with a negligible perceptual difference between both results, allowing us to cut rendering times by 10 whenever we divide SPP by 10. Similarly, we can reduce the number of bounces from 1000 to 100 with a negligible perceptual difference while reducing rendering times by almost half. We also propose a new algorithm in real-time, Lobe Estimator, that approximates these behaviors and parameters while performing twice as faster as the classic Ray Marching technique.Muitas técnicas de ilmuninação volumétrica foram desenvolvidas ao longo dos anos. Entretanto, ainda há muitas restrições na computação de multiple scattering em aplicações de tempo real usando path tracing, devido à sua complexidade e escala. Path tracing com suporte a multiple scattering é capaz de produzir resultados fisicamente corretos, mas sofre de ruídos e baixa taixa de convergência. Portanto, este trabalho propõe um novo algoritmo de tempo real para aproximar multiple scattering, usado em offline rendering. Nossa abordagem irá explorar o sistema perceptual visual humano para acelerar a computação. A partir de duas imagens, nós usamos a métrica da CIE que afirma que duas imagens são percebidas como similar ao olho humano se a distância Euclidiana das duas imagens no espaço de cores CIELAB for menor que 2.3. Dessa forma, nós usamos essa premissa para guiar nossas investigações quando alterando os parâmetros de Samples Per Pixel (SPP) e bounces nos renderizadores. Nossos resultados mostram que podemos redu zir de 105 para 104 Samples Per Pixel (SPP) com uma diferença perceptual negligenciável entre ambos paramêtros, permitindo reduzir o tempo de renderização por 10 a cada vez que dividimos o SPP por 10. Similarmente, nós podemos reduzir o número de bounces de 1000 para 100 com uma diferença perceptual negligenciável, enquanto reduzindo o tempo de renderização por quase metade. Nós também propusemos um novo algoritmo em tempo real, Lobe Estimator, que permite aproximar esses comportamentos e paramê tros enquanto permformando duas vezes mais rápido que o clássico Ray Marching