Henri Gouraud | |
---|---|
Born | 1944 France |
Alma mater | University of Utah École Centrale Paris |
Known for | Gouraud Shading |
Scientific career | |
Fields | Computer science |
Henri Gouraud (born 1944) is a French computer scientist. He is the inventor of Gouraud shading used in computer graphics. He is the great-nephew of general Henri Gouraud.
During 1964–1967, he studied at École Centrale Paris. He received his Ph.D. from the University of Utah College of Engineering in 1971, working with Dave Evans and Ivan Sutherland, with his dissertation titled Computer Display of Curved Surfaces . [1]
In 1971, Gouraud made the first computer graphics geometry capture and representation of a human face in wire-frame model, and applied his shader to produce the famous human face images showing the effect of his shading, which were done using his wife Sylvie Gouraud as the model. [2]
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.
Gouraud shading, named after Henri Gouraud, is an interpolation method used in computer graphics to produce continuous shading of surfaces represented by polygon meshes. In practice, Gouraud shading is most often used to achieve continuous lighting on triangle meshes by computing the lighting at the corners of each triangle and linearly interpolating the resulting colours for each pixel covered by the triangle. Gouraud first published the technique in 1971. However, enhanced hardware support for superior shading models has yielded Gouraud shading largely obsolete in modern rendering.
In 3D computer graphics, Phong shading, Phong interpolation, or normal-vector interpolation shading is an interpolation technique for surface shading invented by computer graphics pioneer Bui Tuong Phong. Phong shading interpolates surface normals across rasterized polygons and computes pixel colors based on the interpolated normals and a reflection model. Phong shading may also refer to the specific combination of Phong interpolation and the Phong reflection model.
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.
Bui Tuong Phong was a Vietnamese-born computer graphics researcher and pioneer. He invented the widely used Phong shading algorithm and Phong reflection model.
Frederic Ira Parke is an American computer graphics researcher and academic. He did early work on animated computer renderings of human faces.
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.
Molecular graphics is the discipline and philosophy of studying molecules and their properties through graphical representation. IUPAC limits the definition to representations on a "graphical display device". Ever since Dalton's atoms and Kekulé's benzene, there has been a rich history of hand-drawn atoms and molecules, and these representations have had an important influence on modern molecular graphics.
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 geometry of computer graphics, a vertex normal at a vertex of a polyhedron is a directional vector associated with a vertex, intended as a replacement to the true geometric normal of the surface. Commonly, it is computed as the normalized average of the surface normals of the faces that contain that vertex. The average can be weighted for example by the area of the face or it can be unweighted. Vertex normals can also be computed for polygonal approximations to surfaces such as NURBS, or specified explicitly for artistic purposes. Vertex normals are used in Gouraud shading, Phong shading and other lighting models. Using vertex normals, much smoother shading than flat shading can be achieved; however, without some modifications to topology such a support loops, it cannot produce a sharper edge.
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.
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.
Computer graphics deals with generating images and art with the aid of computers. Computer graphics is a core technology in digital photography, film, video games, digital art, cell phone and computer displays, and many specialized applications. A great deal of specialized hardware and software has been developed, with the displays of most devices being driven by computer graphics hardware. It is a vast and recently developed area of computer science. The phrase was coined in 1960 by computer graphics researchers Verne Hudson and William Fetter of Boeing. It is often abbreviated as CG, or typically in the context of film as computer generated imagery (CGI). The non-artistic aspects of computer graphics are the subject of computer science research.
Brian A. Barsky is a professor at the University of California, Berkeley, working in computer graphics and geometric modeling as well as in optometry and vision science. He is a Professor of Computer Science and Vision Science and an Affiliate Professor of Optometry. He is also a member of the Joint Graduate Group in Bioengineering, an inter-campus program, between UC Berkeley and UC San Francisco.
The John and Marcia Price College of Engineering at the University of Utah is an academic college of the University of Utah in Salt Lake City, Utah. The college offers undergraduate and graduate degrees in engineering and computer science.
In technical applications of 3D computer graphics (CAx) such as computer-aided design and computer-aided manufacturing, surfaces are one way of representing objects. The other ways are wireframe and solids. Point clouds are also sometimes used as temporary ways to represent an object, with the goal of using the points to create one or more of the three permanent representations.
Computer-generated imagery (CGI) is a specific-technology or application of computer graphics for creating or improving images in art, printed media, simulators, videos and video games. These images are either static or dynamic. CGI both refers to 2D computer graphics and 3D computer graphics with the purpose of designing characters, virtual worlds, or scenes and special effects. The application of CGI for creating/improving animations is called computer animation, or CGI animation.
A Computer Animated Hand is the title of a 1972 American computer-animated short film produced by Edwin Catmull and Fred Parke. Produced during Catmull's tenure at the University of Utah, the short was created for a graduate course project. After creating a model of his left hand, 350 triangles and polygons were drawn in ink on its surface. The model was digitized from the data and laboriously animated in a three-dimensional animation program that Catmull wrote.
The Kahlert School of Computing is a school within the College of Engineering at the University of Utah in Salt Lake City, Utah.