Gooch shading is a non-photorealistic rendering technique for shading objects. It is also known as "cool to warm" shading, and is widely used in technical illustration.
Gooch shading was developed by Amy Gooch et al. at the University of Utah School of Computing and first presented at the 1998 SIGGRAPH conference. [1] [2] It has since been implemented in shader libraries, software, and games released by Autodesk, NVIDIA, and Valve. [3] [4] [5]
Gooch shading defines an additional two colors in conjunction with the original model color: a warm color (such as yellow) and a cool color (such as blue). The warm color indicates surfaces that are facing toward the light source while the cool color indicates surfaces facing away. This allows shading to occur only in mid-tones so that edge lines and highlights remain visually prominent. The Gooch shader is typically implemented in two passes: all objects in the scene are first drawn with the "cool to warm" shading, and in the second pass the object’s edges are rendered in black.
Rendering or image synthesis is the process of generating a photorealistic or non-photorealistic image from a 2D or 3D model by means of a computer program. The resulting image is referred to as a rendering. Multiple models can be defined in a scene file containing objects in a strictly defined language or data structure. The scene file contains geometry, viewpoint, textures, lighting, and shading information describing the virtual scene. The data contained in the scene file is then passed to a rendering program to be processed and output to a digital image or raster graphics image file. The term "rendering" is analogous to the concept of an artist's impression of a scene. The term "rendering" is also used to describe the process of calculating effects in a video editing program to produce the final video output.
In 3D computer graphics, ray tracing is a technique for modeling light transport for use in a wide variety of rendering algorithms for generating digital images.
Shading refers to the depiction of depth perception in 3D models or illustrations by varying the level of darkness. Shading tries to approximate local behavior of light on the object's surface and is not to be confused with techniques of adding shadows, such as shadow mapping or shadow volumes, which fall under global behavior of light.
A particle system is a technique in game physics, motion graphics, and computer graphics that uses many minute sprites, 3D models, or other graphic objects to simulate certain kinds of "fuzzy" phenomena, which are otherwise very hard to reproduce with conventional rendering techniques – usually highly chaotic systems, natural phenomena, or processes caused by chemical reactions.
Cel shading or toon shading is a type of non-photorealistic rendering designed to make 3-D computer graphics appear to be flat by using less shading color instead of a shade gradient or tints and shades. A cel shader is often used to mimic the style of a comic book or cartoon and/or give the render a characteristic paper-like texture. There are similar techniques that can make an image look like a sketch, an oil painting or an ink painting. The name comes from cels, clear sheets of acetate which were painted on for use in traditional 2D animation.
In scientific visualization and computer graphics, volume rendering is a set of techniques used to display a 2D projection of a 3D discretely sampled data set, typically a 3D scalar field.
Non-photorealistic rendering (NPR) is an area of computer graphics that focuses on enabling a wide variety of expressive styles for digital art, in contrast to traditional computer graphics, which focuses on photorealism. NPR is inspired by other artistic modes such as painting, drawing, technical illustration, and animated cartoons. NPR has appeared in movies and video games in the form of cel-shaded animation as well as in scientific visualization, architectural illustration and experimental animation.
High-dynamic-range rendering, also known as high-dynamic-range lighting, is the rendering of computer graphics scenes by using lighting calculations done in high dynamic range (HDR). This allows preservation of details that may be lost due to limiting contrast ratios. Video games and computer-generated movies and special effects benefit from this as it creates more realistic scenes than with more simplistic lighting models.
In computer graphics, per-pixel lighting refers to any technique for lighting an image or scene that calculates illumination for each pixel on a rendered image. This is in contrast to other popular methods of lighting such as vertex lighting, which calculates illumination at each vertex of a 3D model and then interpolates the resulting values over the model's faces to calculate the final per-pixel color values.
3D rendering is the 3D computer graphics process of converting 3D models into 2D images on a computer. 3D renders may include photorealistic effects or non-photorealistic styles.
Patrick M. Hanrahan is an American computer graphics researcher, the Canon USA Professor of Computer Science and Electrical Engineering in the Computer Graphics Laboratory at Stanford University. His research focuses on rendering algorithms, graphics processing units, as well as scientific illustration and visualization. He has received numerous awards, including the 2019 Turing Award.
Computer graphics lighting is the collection of techniques used to simulate light in computer graphics scenes. While lighting techniques offer flexibility in the level of detail and functionality available, they also operate at different levels of computational demand and complexity. Graphics artists can choose from a variety of light sources, models, shading techniques, and effects to suit the needs of each application.
In the field of 3D computer graphics, deferred shading is a screen-space shading technique that is performed on a second rendering pass, after the vertex and pixel shaders are rendered. It was first suggested by Michael Deering in 1988.
Computer graphics is a sub-field of computer science which studies methods for digitally synthesizing and manipulating visual content. Although the term often refers to the study of three-dimensional computer graphics, it also encompasses two-dimensional graphics and image processing.
The Scientific Computing and Imaging (SCI) Institute is a permanent research institute at the University of Utah that focuses on the development of new scientific computing and visualization techniques, tools, and systems with primary applications to biomedical engineering. The SCI Institute is noted worldwide in the visualization community for contributions by faculty, alumni, and staff. Faculty are associated primarily with the School of Computing, Department of Bioengineering, Department of Mathematics, and Department of Electrical and Computer Engineering, with auxiliary faculty in the Medical School and School of Architecture.
Amy Ashurst Gooch is a computer scientist known for her contributions in non-photorealistic rendering. She is currently the Chief Operations Officer at ViSOAR LLC, a data visualization research spin-off software company from the Scientific Computing and Imaging Institute. She is also an adjunct professor of computer science at Texas A&M University. Her current research is part of an interdisciplinary effort involving computer graphics, perceptual psychology, and computational vision. She is interested in better understanding the spatial information potentially available in CG imagery, determining what spatial cues are actually used when CG imagery is viewed, and using this information to create improved rendering algorithms and visualizations.
Autodesk Arnold is a computer program for rendering three-dimensional, computer-generated scenes using unbiased, physically-based, Monte Carlo path tracing techniques. Created in Spain by Marcos Fajardo and later co-developed by his company Solid Angle SL and Sony Pictures Imageworks, Arnold is one of the most widely used photorealistic rendering systems in computer graphics worldwide, particularly in animation and VFX for film and TV. Notable feature films that have used Arnold include Monster House, Cloudy with a Chance of Meatballs, Alice in Wonderland, Thor, Captain America, X-Men: First Class, The Avengers, Space Pirate Captain Harlock, Elysium, Pacific Rim, Gravity, Guardians of the Galaxy, Star Wars: The Force Awakens, Arrival and Blade Runner 2049. Notable television series include Game of Thrones, Westworld, Trollhunters, LOVE DEATH + ROBOTS, Jelly Jamm and The Mandalorian.
This is a glossary of terms relating to computer graphics.
Physically based rendering (PBR) is a computer graphics approach that seeks to render images in a way that models the lights and surfaces with optics in the real world. It is often referred to as "Physically Based Lighting" or "Physically Based Shading". Many PBR pipelines aim to achieve photorealism. Feasible and quick approximations of the bidirectional reflectance distribution function and rendering equation are of mathematical importance in this field. Photogrammetry may be used to help discover and encode accurate optical properties of materials. PBR principles may be implemented in real-time applications using Shaders or offline applications using ray tracing or path tracing.
Michael F. Cohen is an American computer scientist and researcher in computer graphics. He is currently a Senior Fellow at Meta in their Generative AI Group. He was a senior research scientist at Microsoft Research for 21 years until he joined Facebook in 2015. In 1998, he received the ACM SIGGRAPH CG Achievement Award for his work in developing radiosity methods for realistic image synthesis. He was elected a Fellow of the Association for Computing Machinery in 2007 for his "contributions to computer graphics and computer vision." In 2019, he received the ACM SIGGRAPH Steven A. Coons Award for Outstanding Creative Contributions to Computer Graphics for “his groundbreaking work in numerous areas of research—radiosity, motion simulation & editing, light field rendering, matting & compositing, and computational photography”.