Simulation noise
Encyclopedia
Simulation noise is a function
that creates a divergence-free field. This signal can be used in artistic simulations for the purposes of increasing the perception of extra detail.
The function can be calculated in three dimensions by dividing the space into a regular lattice grid. With each edge is associated a random value, indicating a rotational component of material revolving around the edge. By following rotating material into and out of faces, one can quickly sum the flux passing through each face of the lattice. Flux values at lattice faces are then interpolated to create a field value for all positions.
Perlin noise
is the earliest form of lattice noise, which has become very popular in computer graphics
. Perlin Noise is not suited for simulation because it is not divergence-free.
Noises based on lattices, such as simulation noise and Perlin noise, are often calculated at different frequencies and summed together to form band-limited fractal
signals.
Other approaches developed later that use vector calculus identities to produce divergence free fields, such as "Curl-Noise" as suggested by Robert Bridson, and "Divergence-Free Noise" due to Ivan DeWolf. These often require calculation of lattice noise gradients, which are not sometimes not readily available. A naive implementation would call a lattice noise function several times to calculate its gradient, resulting in more computation than is strictly necessary. Unlike these noises, simulation noise has a geometric rational in addition to its mathematical properties. It simulates vortices scattered in space, to produce its pleasing aesthetic.
Function (mathematics)
In mathematics, a function associates one quantity, the argument of the function, also known as the input, with another quantity, the value of the function, also known as the output. A function assigns exactly one output to each input. The argument and the value may be real numbers, but they can...
that creates a divergence-free field. This signal can be used in artistic simulations for the purposes of increasing the perception of extra detail.
The function can be calculated in three dimensions by dividing the space into a regular lattice grid. With each edge is associated a random value, indicating a rotational component of material revolving around the edge. By following rotating material into and out of faces, one can quickly sum the flux passing through each face of the lattice. Flux values at lattice faces are then interpolated to create a field value for all positions.
Perlin noise
Perlin noise
Perlin noise is a computer-generated visual effect developed by Ken Perlin, who won an Academy Award for its use in the motion picture Tron...
is the earliest form of lattice noise, which has become very popular in computer graphics
Computer graphics
Computer graphics are graphics created using computers and, more generally, the representation and manipulation of image data by a computer with help from specialized software and hardware....
. Perlin Noise is not suited for simulation because it is not divergence-free.
Noises based on lattices, such as simulation noise and Perlin noise, are often calculated at different frequencies and summed together to form band-limited fractal
Fractal
A fractal has been defined as "a rough or fragmented geometric shape that can be split into parts, each of which is a reduced-size copy of the whole," a property called self-similarity...
signals.
Other approaches developed later that use vector calculus identities to produce divergence free fields, such as "Curl-Noise" as suggested by Robert Bridson, and "Divergence-Free Noise" due to Ivan DeWolf. These often require calculation of lattice noise gradients, which are not sometimes not readily available. A naive implementation would call a lattice noise function several times to calculate its gradient, resulting in more computation than is strictly necessary. Unlike these noises, simulation noise has a geometric rational in addition to its mathematical properties. It simulates vortices scattered in space, to produce its pleasing aesthetic.