computer graphics Computer graphics deals with generating images with the aid of computers. Today, computer graphics is a core technology in digital photography, film, video games, cell phone and computer displays, and many specialized applications. A great deal ...

, a procedural surface is a representation of a

surface A surface, as the term is most generally used, is the outermost or uppermost layer of a physical object or space. It is the portion or region of the object that can first be perceived by an observer using the senses of sight and touch, and is t ...

as a mathematical

implicit equation In mathematics, an implicit equation is a relation of the form R(x_1, \dots, x_n) = 0, where is a function of several variables (often a polynomial). For example, the implicit equation of the unit circle is x^2 + y^2 - 1 = 0. An implicit fun ...

, rather than an explicit representation. An explicit representation, for example, describes a line as the straight segment going through two given points. A procedural surface is one which is defined as a procedure. For example, in

CAD Computer-aided design (CAD) is the use of computers (or ) to aid in the creation, modification, analysis, or optimization of a design. This software is used to increase the productivity of the designer, improve the quality of design, improve c ...

Computer-aided manufacturing Computer-aided manufacturing (CAM) also known as computer-aided modeling or computer-aided machining is the use of software to control machine tools in the manufacturing of work pieces. This is not the only definition for CAM, but it is the most ...

milling Milling may refer to: * Milling (minting), forming narrow ridges around the edge of a coin * Milling (grinding), breaking solid materials into smaller pieces by grinding, crushing, or cutting in a mill * Milling (machining), a process of using rota ...

applications, an

offset surface A parallel of a curve is the envelope of a family of congruent circles centered on the curve. It generalises the concept of '' parallel (straight) lines''. It can also be defined as a curve whose points are at a constant '' normal distance'' ...

is a procedural representation because it is defined as the surface which is a fixed distance from another surface. Another well-known procedural edge on a 3D body is the

silhouette edge In computer graphics, a silhouette edge on a 3D body projected onto a 2D plane (display plane) is the collection of points whose outwards ''surface normal is perpendicular to the view vector''. Due to discontinuities in the surface normal, a silhou ...

. This edge is defined as the collection of points on a surface whose outwards

surface normal In geometry, a normal is an object such as a line, ray, or vector that is perpendicular to a given object. For example, the normal line to a plane curve at a given point is the (infinite) line perpendicular to the tangent line to the curve ...

is perpendicular to the

view vector This is a glossary of terms relating to computer graphics. For more general computer hardware terms, see glossary of computer hardware terms. 0–9 A B ...

. Another example of a procedural surface is a

Blob Blob may refer to: Science Computing * Binary blob, in open source software, a non-free object file loaded into the kernel * Binary large object (BLOB), in computer database systems * A storage mechanism in the cloud computing platform Mi ...

as illustrated in movies like ''

The Abyss ''The Abyss'' is a 1989 American science fiction film written and directed by James Cameron and starring Ed Harris, Mary Elizabeth Mastrantonio, and Michael Biehn. When an American submarine sinks in the Caribbean, a US search and recovery te ...

'' in the scene where the creature made up of water reaches out and touches the character. The surface is defined as a surface which exists when two or more control points are oriented in such a way as to make the contribution potential exceed a certain threshold. Such procedural surfaces require far more processing to calculate, and for this reason are often used in pre-rendered rather than real-time applications. This approach is commonly used by structural chemists and was defined by van der Waals when defining a region of space where the electric charge

equipotential surface In mathematics and physics, an equipotential or isopotential refers to a region in space where every point is at the same potential. This usually refers to a scalar potential (in that case it is a level set of the potential), although it can al ...

had a definite value.

References

{{DEFAULTSORT:Procedural Surface Computer graphics data structures