Astrid/perlin_noise.scad
2024-12-21 21:35:09 +01:00

103 lines
2.7 KiB
OpenSCAD

// $fn=3;
// randomize = true;
// setseed = 123456;
// seed = randomize ? floor(rands(0, 1000000, 1)[0]) : setseed;
// echo(Seed = seed);
{
// Functions
{
// Main noise generator
//
// b = base random array, don't set this
// a = recursion array, don't set this!
// no = number of octaves, you can set this, number of elements is no^2
// o = current octave iteration, don't set this
// seed = rands seed, you can set this
//
// Returns: Perlin noise array, length(no ^ 2)
function perlin_noise(b=[], a=[], no=4, o=0, seed=0) =
(o > no)
? scalevec(2, a) // Done, return the array
: (len(b) == 0)
? perlin_noise(rands(0, 1, no ^ 2, seed), a=[], no=no, o=o, seed=seed)
: (len(a) == 0)
? perlin_noise(b=b, a=octave(o=0, b=b), no=no, o=o + 1, seed=seed)
: perlin_noise(b=b, a=addvec(a, octave(o=o, b=b)), no=no, o=o + 1, seed=seed);
}
// ^ Main noise generator
{
// Octave generator
//
// o = octave
// b = base random array
//
// Returns: array of values from a single noise octave
function octave(o=0, b=[]) =
expand(c=len(b), a=[
for(i=[0 : len(b) / (2 ^ o) : len(b) - 1]) b[i]
]);
}
// ^ Octave generator
{
// Expand octave
//
// c = base array length
// a = octave array
//
// Returns: array of length=length(base) with interpolated octave values
function expand(c=0, a=[]) = [
for(i=[0 : c - 1])
(len(a) == 1)
? a[0]
: (len(a) == c)
? a[i] * (c / len(a) / c)
: (interp(v=[
a[floor(i / (c / len(a)))],
(floor(i / (c / len(a))) + 1 == len(a))
? a[0]
: a[floor(i / (c / len(a))) + 1]],
s=c / len(a))
* (i % (c / len(a)))
+ a[floor(i / (c / len(a)))])
* ((c / len(a)) / c)
];
}
// ^ Expand octave
{
// Helper functions
function interp(v=[], s=0) = (v[1] - v[0]) / s;
function addvec(a=[], b=[]) = [
for(i=[0 : len(a) - 1])
a[i] + b[i]
];
function scalevec(d=2, v=[]) = [
for(i=[0 : len(v) - 1])
v[i] / d
];
}
// ^ Helper functions
}
// ^ Functions
// // Example:
// //
// // no = 8 means we will get a noise array with 8 ^ 2 = 64 values (range 0-1)
// // seed = seed, this is set up with the variables above, you could set it manually. Defaults to 0 if not set
// a = noise(no=8, seed=seed);
// // This displays the values.
// repeat = 1;
// for(i=[0 : len(a) - 1], x=[0 : repeat]) {
// translate([i + len(a) * x, 0, 0]) cylinder(a[i] * 100, d=1);
// }