The RenderMan Interface Specification, or RISpec in short, is an open API developed by Pixar Animation Studios to describe three-dimensional scenes and turn them into digital photorealistic images. It includes the RenderMan Shading Language.
Constructive solid geometry is a technique used in solid modeling. Constructive solid geometry allows a modeler to create a complex surface or object by using Boolean operators to combine simpler objects, potentially generating visually complex objects by combining a few primitive ones.
In computer graphics, a shader is a computer program that calculates the appropriate levels of light, darkness, and color during the rendering of a 3D scene—a process known as shading. Shaders have evolved to perform a variety of specialized functions in computer graphics special effects and video post-processing, as well as general-purpose computing on graphics processing units.
In computer graphics, level of detail (LOD) refers to the complexity of a 3D model representation. LOD can be decreased as the model moves away from the viewer or according to other metrics such as object importance, viewpoint-relative speed or position. LOD techniques increase the efficiency of rendering by decreasing the workload on graphics pipeline stages, usually vertex transformations. The reduced visual quality of the model is often unnoticed because of the small effect on object appearance when distant or moving fast.
In computing, procedural generation is a method of creating data algorithmically as opposed to manually, typically through a combination of human-generated content and algorithms coupled with computer-generated randomness and processing power. In computer graphics, it is commonly used to create textures and 3D models. In video games, it is used to automatically create large amounts of content in a game. Depending on the implementation, advantages of procedural generation can include smaller file sizes, larger amounts of content, and randomness for less predictable gameplay. Procedural generation is a branch of media synthesis.
Texture synthesis is the process of algorithmically constructing a large digital image from a small digital sample image by taking advantage of its structural content. It is an object of research in computer graphics and is used in many fields, amongst others digital image editing, 3D computer graphics and post-production of films.
Generative Modelling Language (GML) in computer graphics and generative computer programming is a very simple programming language for the concise description of complex 3D shapes. It follows the "Generative Modelling" paradigm, where complex datasets are represented by "lists of operations" rather than by lists of objects, which is for instance the case in a relational database.
3D computer graphics, sometimes called CGI, 3-D-CGI or three-dimensional computer graphics, are graphics that use a three-dimensional representation of geometric data that is stored in the computer for the purposes of performing calculations and rendering digital images, usually 2D images but sometimes 3D images. The resulting images may be stored for viewing later or displayed in real time.
A scenery generator is software used to create landscape images, 3D models, and animations. These programs often use procedural generation to generate the landscapes. If not using procedural generation to create the landscapes, then normally a 3D artist would render and create the landscapes. These programs are often used in video games or movies. Basic elements of landscapes created by scenery generators include terrain, water, foliage, and clouds. The process for basic random generation uses a diamond square algorithm.
Gradient noise is a type of noise commonly used as a procedural texture primitive in computer graphics. It is conceptually different from, and often confused with, value noise. This method consists of a creation of a lattice of random gradients, dot products of which are then interpolated to obtain values in between the lattices. An artifact of some implementations of this noise is that the returned value at the lattice points is 0. Unlike the value noise, gradient noise has more energy in the high frequencies.
Geometrical design (GD) is a branch of computational geometry. It deals with the construction and representation of free-form curves, surfaces, or volumes and is closely related to geometric modeling. Core problems are curve and surface modelling and representation. GD studies especially the construction and manipulation of curves and surfaces given by a set of points using polynomial, rational, piecewise polynomial, or piecewise rational methods. The most important instruments here are parametric curves and parametric surfaces, such as Bézier curves, spline curves and surfaces. An important non-parametric approach is the level-set method.
Generative design is an iterative design process that uses software to generate outputs that fulfill a set of constraints iteratively adjusted by a designer. Whether a human, test program, or artificial intelligence, the designer algorithmically or manually refines the feasible region of the program's inputs and outputs with each iteration to fulfill evolving design requirements. By employing computing power to evaluate more design permutations than a human alone is capable of, the process is capable of producing an optimal design that mimics nature's evolutionary approach to design through genetic variation and selection. The output can be images, sounds, architectural models, animation, and much more. It is therefore a fast method of exploring design possibilities that is used in various design fields such as art, architecture, communication design, and product design.
Worley noise, also called Voronoi noise and cellular noise, is a noise function introduced by Steven Worley in 1996. Worley noise is an extension of the Voronoi diagram that outputs a real value at a given coordinate that corresponds to the Distance of the nth nearest seed, usually nearest seed, and the seeds are distributed evenly through the region. Worley noise is used to create procedural textures.
ArcGIS CityEngine is a commercial three-dimensional (3D) modeling program developed by Esri R&D Center Zurich and specialises in the generation of 3D urban environments. Using a procedural modeling approach, it supports the creation of detailed large-scale 3D city models. CityEngine works with architectural object placement and arrangement in the same manner that software like VUE manages terrain, ecosystems and atmosphere mapping. Unlike the traditional 3D modeling methodology which uses Computer-Aided Design (CAD) tools and techniques, CityEngine takes a different approach to shape generation via a rule-based system. It can also use Geographic Information System (GIS) datasets due to its integration with the wider Esri/ArcGIS platform. Due to this unique feature set, CityEngine has been used in academic research and built environment professions, e.g., urban planning, architecture, visualization, game development, entertainment, archeology, military and cultural heritage. CityEngine can be used within Building Information Model (BIM) workflows as well as visualizing the data of buildings in a larger urban context, enhancing its working scenario toward real construction projects.
In 3D computer graphics, 3D modeling is the process of developing a mathematical coordinate-based representation of a surface of an object in three dimensions via specialized software by manipulating edges, vertices, and polygons in a simulated 3D space.
In computer graphics, a procedural texture is a texture created using a mathematical description rather than directly stored data. The advantage of this approach is low storage cost, unlimited texture resolution and easy texture mapping. These kinds of textures are often used to model surface or volumetric representations of natural elements such as wood, marble, granite, metal, stone, and others.
Maxon Computer GmbH is a German software company that produces software for content creators. The company’s product lines include the 3D software Cinema 4D, the Red Giant tools for editing, motion design and filmmaking, Redshift renderer and the digital sculpting and painting software ZBrush as well as the mobile sculpting app Forger. The company’s cross-platform benchmarking application Cinebench is used by developers, reviewers and users to evaluate hardware performance.
Parametric design is a design method in which features, such as building elements and engineering components, are shaped based on algorithmic processes rather than direct manipulation. In this approach, parameters and rules establish the relationship between design intent and design response. The term parametric refers to the input parameters that are fed into the algorithms.
This is a glossary of terms relating to computer graphics.
David S. Ebert is a computer scientist, holding the position of Silicon Valley Professor of Electrical and Computer Engineering Department at Purdue University.
