Shader

Abstract: To accurately render a two-dimensional image of a three-dimensional scene, global illumination information that affects the intensity of each pixel of the image must be known at the time the intensity is calculated. In a simplified form, this information is stored in a tree of “rays” extending from the viewer to the first surface encountered and from there to other surfaces and to the light sources. A visible surface algorithm creates this tree for each pixel of the display and passes it to the shader. The shader then traverses the tree to determine the intensity of the light received by the viewer. Consideration of all of these factors allows the shader to accurately simulate true reflection, shadows, and refraction, as well as the effects simulated by conventional shaders. Anti-aliasing is included as an integral part of the visibility calculations. Surfaces displayed include curved as well as polygonal surfaces.

Abstract: SUMMARY: Today's graphics processing units (GPUs) compose the scene from individual triangles. As about 320 triangles are needed to approximate a single sphere-an atom-in a convincing way, visualizing larger proteins with atomic details requires tens of millions of triangles, far too many for smooth interactive frame rates. We describe a new approach to solve this 'molecular graphics problem', which shares the work between GPU and multiple CPU cores, generates high-quality results with perfectly round spheres, shadows and ambient lighting and requires only OpenGL 1.0 functionality, without any pixel shader Z-buffer access (a feature which is missing in most mobile devices). AVAILABILITY AND IMPLEMENTATION: YASARA View, a molecular modeling program built around the visualization algorithm described here, is freely available (including commercial use) for Linux, MacOS, Windows and Android (Intel) from www.YASARA.org. CONTACT: elmar@yasara.org SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Abstract: We introduce a novel texture-based volume rendering approach that achieves the image quality of the best post-shading approaches with far less slices. It is suitable for new flexible consumer graphics hardware and provides high image quality even for low-resolution volume data and non-linear transfer functions with high frequencies, without the performance overhead caused by rendering additional interpolated slices. This is especially useful for volumetric effects in computer games and professional scientific volume visualization, which heavily depend on memory bandwidth and rasterization power.We present an implementation of the algorithm on current programmable consumer graphics hardware using multi-textures with advanced texture fetch and pixel shading operations. We implemented direct volume rendering, volume shading, arbitrary number of isosurfaces, and mixed mode rendering. The performance does neither depend on the number of isosurfaces nor the definition of the transfer functions, and is therefore suited for interactive high-quality volume graphics.

Abstract: As the Red Book is known to be the gold standard for OpenGL, the Orange Book is considered to be the gold standard for the OpenGL Shading Language. With Randis extensive knowledge of OpenGL and GLSL, you can be assured you will be learning from a graphics industry veteran. Within the pages of the second edition you can find topics from beginning shader development to advanced topics such as the spherical harmonic lighting model and more. David Tommeraasen, CEO/Programmer, Plasma Software This will be the definitive guide for OpenGL shaders; no other book goes into this detail. Rost has done an excellent job at setting the stage for shader development, what the purpose is, how to do it, and how it all fits together. The book includes great examples and details, as well as good additional coverage of 2.0 changes! Jeffery Galinovsky, Director of Emerging Market, Platform Development, Intel Corporation The coverage in this new edition of the book is pitched just right to help many new shader-writers get started, but with enough deep information for the old hands. Marc Olano, Assistant Professor, University of Maryland This is a really great book on GLSLwell written and organized, very accessible, and with good real-world examples and sample code. The topics flow naturally and easily, explanatory code fragments are inserted in very logical places to illustrate concepts, and, all in all, this book makes an excellent tutorial as well as a reference. John Carey, Chief Technology Officer, C.O.R.E. Feature Animation OpenGL Shading Languageprovides a timely, thorough, and entertaining introduction to the only OpenGL ARB-approved high-level shading language in existence. Whether an expert or a novice, there are gems to be discovered throughout the book, and the reference pages will be your constant companion as you dig into the depths of the shading APIs. From algorithms to APIs, this book has you covered. Bob Kuehne, CEO, Blue Newt Software Computer graphics and rendering technologies just took a giant leap forward with hardware vendors rapidly adopting the new OpenGL Shading Language. This book presents a detailed treatment of these exciting technologies in a way that is extremely helpful for visualization and game developers. Andy McGovern, Founder, Virtual Geographics, Inc. The OpenGL Shading Language is at the epicenter of the programmable graphics revolution, and Randi Rost has been at the center of the development of this significant new industry standard. If you need the inside track on how to use the OpenGL Shading Language to unleash new visual effects and unlock the supercomputer hiding inside the new generation of graphics hardware, then this is the book for you. Neil Trevett, Senior Vice President, Market Development, 3Dlabs OpenGL Shading Language, Third Edition, extensively updated for OpenGL 3.1, is the experienced application programmers guide to writing shaders. Part reference, part tutorial, this book thoroughly explains the shift from fixed-functionality graphics hardware to the new era of programmable graphics hardware and the additions to the OpenGL API that support this programmability. With OpenGL and shaders written in the OpenGL Shading Language, applications can perform better, achieving stunning graphics effects by using the capabilities of both the visual processing unit and the central processing unit. In this book, you will find a detailed introduction to the OpenGL Shading Language (GLSL) and the new OpenGL function calls that support it. The text begins by describing the syntax and semantics of this high-level programming language. Once this foundation has been established, the book explores the creation and manipulation of shaders using new OpenGL function calls. OpenGL Shading Language, Third Edition, includes updated descriptions for the language and all the GLSL entry points added though OpenGL 3.1, as well as updated chapters that discuss transformations, lighting, shadows, and surface characteristics. The third edition also features shaders that have been updated to OpenGL Shading Language Version 1.40 and their underlying algorithms, including Traditional OpenGL fixed functionality Stored textures and procedural textures Image-based lighting Lighting with spherical harmonics Ambient occlusion and shadow mapping Volume shadows using deferred lighting Wards BRDF model The color plate section illustrates the power and sophistication of the OpenGL Shading Language. The API Function Reference at the end of the book is an excellent guide to the API entry points that support the OpenGL Shading Language.