Vector slime
Encyclopedia
In the demoscene
(demo (computer programming)
), vector slime refers to a class of visual effects achieved by procedural deformation of geometric shapes.
. In the process of deformation, each vertex in the original shape undergoes one or more linear transformations (usually rotation
or translation
), defined as a function of the vertex' position in space (usually a function of the magnitude of the vector) and time. The desired result is an animated geometric object behaving in a harmonic way, creating some degree of illusion of physical realism.
Older vector slime implementations kept old copies of the rendering result from simple vector objects in RAM, and selected scan-lines from the different buffers in order to make a time-displacement illusion over the y-axis.
, the object would appear as a cubic piece of jelly
propelled by a gyro
force from the inside.
to create impressive visual effects at relatively low computational cost. Interactive vector slime implementations can also eventually be found in computer games as a substitute for a more correct physical simulation algorithm.
Demoscene
The demoscene is a computer art subculture that specializes in producing demos, which are non-interactive audio-visual presentations that run in real-time on a computer...
(demo (computer programming)
Demo (computer programming)
A demo is a non-interactive multimedia presentation made within the computer subculture known as the demoscene. Demogroups create demos to demonstrate their abilities in programming, music, drawing, and 3D modeling...
), vector slime refers to a class of visual effects achieved by procedural deformation of geometric shapes.
Synopsis
A geometric object exposed to vector slime is usually defined by vertices and faces in two or three dimensionsDimensions
Dimensions is a French project that makes educational movies about mathematics, focusing on spatial geometry. It uses POV-Ray to render some of the animations, and the films are release under a Creative Commons licence....
. In the process of deformation, each vertex in the original shape undergoes one or more linear transformations (usually rotation
Rotation
A rotation is a circular movement of an object around a center of rotation. A three-dimensional object rotates always around an imaginary line called a rotation axis. If the axis is within the body, and passes through its center of mass the body is said to rotate upon itself, or spin. A rotation...
or translation
Translation
Translation is the communication of the meaning of a source-language text by means of an equivalent target-language text. Whereas interpreting undoubtedly antedates writing, translation began only after the appearance of written literature; there exist partial translations of the Sumerian Epic of...
), defined as a function of the vertex' position in space (usually a function of the magnitude of the vector) and time. The desired result is an animated geometric object behaving in a harmonic way, creating some degree of illusion of physical realism.
Older vector slime implementations kept old copies of the rendering result from simple vector objects in RAM, and selected scan-lines from the different buffers in order to make a time-displacement illusion over the y-axis.
Appearance
Depending on variances in implementation, vector slime can approximate an array of physical properties. A traditional approach is to let the linear transformation vary as a smooth function of time minus the magnitude of the vector in question. This creates the illusion that there is a force applied to the origin of the object space (where the object is usually centered), and the rest of the object's body reacts as a soft body, as each vertex reacts to a change in the force delayed by the distance to the origin. Applied to a spikeball (a sphere with extracted arms), the object could resemble the behaviour of a soft squid-like animal. Applied to a cubeCube
In geometry, a cube is a three-dimensional solid object bounded by six square faces, facets or sides, with three meeting at each vertex. The cube can also be called a regular hexahedron and is one of the five Platonic solids. It is a special kind of square prism, of rectangular parallelepiped and...
, the object would appear as a cubic piece of jelly
Gelatin dessert
Gelatin desserts are desserts made with sweetened and flavored gelatin. They can be made by combining plain gelatin with other ingredients or by using a premixed blend of gelatin with additives...
propelled by a gyro
Gyro
- Science and technology :* An abbreviation for gyroscope, an orientation-stabilizing device* An abbreviation for autogyro, a type of rotary-wing aircraft* The casually used brand name of a detangler mechanism, part of a stunt-adapted BMX bicycle...
force from the inside.
Areas of Application
Although the classical vector slime algorithms are far from an attempt of correct physical modelling, the result can, under certain conditions, trick the viewer into believing that there is some sophisticated physical simulation involved. The effect has therefore grown quite popular in the demosceneDemoscene
The demoscene is a computer art subculture that specializes in producing demos, which are non-interactive audio-visual presentations that run in real-time on a computer...
to create impressive visual effects at relatively low computational cost. Interactive vector slime implementations can also eventually be found in computer games as a substitute for a more correct physical simulation algorithm.
Demos featuring vector slime
- Crystal Dream 2Crystal Dream 2Crystal Dream 2 is a PC demo by the demogroup Triton. It was released in 1993 at The Computer Crossroads demo party where it ranked 1st.Crystal Dream 2 is often considered one of the most influential classical PC demos, on par with Second Reality, released the same year by Future Crew.-...
by Triton http://www.pouet.net/prod.php?which=462 - Lethal Exit by Digital http://www.pouet.net/prod.php?which=3226 (possibly the first demo to use this term)
- Yuri Nation by Non Alien Nature-V http://www.pouet.net/prod.php?which=1943 (possibly the first hardware vector slime)
- Shapeshifter by Excess http://www.pouet.net/prod.php?which=6983