[英]JavaScript simplex / perlin noise
我正在嘗試在JavaScript中創建一個perlin / simplex / value噪聲函數,它將產生類似於以下內容的結果:
(注意:此圖像已經應用了閾值。我希望它沒有閾值。)
我已經在互聯網上看了2天了。 有很多鏈接可以解釋噪聲和很多代碼,但JavaScript中沒有,每當我嘗試轉換它時,我都會得到奇怪的結果。 以下是我的一些嘗試:
我認為問題的一部分可能源於在JavaScript中使用按位運算符,其中很難強制執行數字類型。
我正在尋找的是一個工作的例子,JavaScript噪音(無論什么類型)。
我也願意為有關參數的任何信息提供獎勵,這些信息可能導致類似於我發布的圖像(閾值之前)或任何優化提示的模式,因為我需要盡可能快地運行(盡管如此)。
我不久前做過這樣的事,但是我使用了中點位移。 如果你能弄清楚它們會有什么幫助,
http://www.somethinghitme.com/projects/canvasterrain/
它也在這里
https://github.com/loktar00/Javascript-Canvas-Terrain-Generator
這里只是用一些很酷的燈光實現的噪音部分,
http://jsfiddle.net/loktar/4qAxZ/
祝好運 :)。
我知道這已經很老了,但也許它對其他人來說仍然有用。 我已經構建了一個將Perlin和Simplex噪音呈現給HTML5畫布的javascript應用程序,請在此處查看: http : //lencinhaus.github.com/canvas-noise
該應用程序允許調整噪聲計算和渲染中涉及的每個參數,並保存生成的紋理。 它還將參數添加到URL,以便可以共享它。 例如, 此配置會生成與您顯示的紋理非常相似的紋理。
希望有所幫助!
這就是我最終得到的2D / 3D Perlin噪聲代碼。 請注意,它使用RequireJS的AMD模塊語法,但如果您不使用AMD加載程序,則可以將其刪除。
define(
[],
function()
{
function fade(t)
{
return t * t * t * (t * (t * 6 - 15) + 10);
}
function lerp(t, a, b)
{
return a + t * (b - a);
}
function grad(hash, x, y, z)
{
// Convert lo 4 bits of hash code into 12 gradient directions.
var h = hash & 15,
u = h < 8 ? x : y,
v = h < 4 ? y : h == 12 || h == 14 ? x : z;
return ((h & 1) == 0 ? u : -u) + ((h & 2) == 0 ? v : -v);
}
function scale(n)
{
return (1 + n) / 2;
}
var p = new Array(512);
var permutation = [
151, 160, 137, 91, 90, 15, 131, 13, 201, 95, 96, 53, 194, 233, 7, 225, 140, 36, 103, 30, 69, 142, 8, 99,
37, 240, 21, 10, 23, 190, 6, 148, 247, 120, 234, 75, 0, 26, 197, 62, 94, 252, 219, 203, 117, 35, 11, 32,
57, 177, 33, 88, 237, 149, 56, 87, 174, 20, 125, 136, 171, 168, 68, 175, 74, 165, 71, 134, 139, 48, 27, 166,
77, 146, 158, 231, 83, 111, 229, 122, 60, 211, 133, 230, 220, 105, 92, 41, 55, 46, 245, 40, 244, 102, 143,
54, 65, 25, 63, 161, 1, 216, 80, 73, 209, 76, 132, 187, 208, 89, 18, 169, 200, 196, 135, 130, 116, 188, 159,
86, 164, 100, 109, 198, 173, 186, 3, 64, 52, 217, 226, 250, 124, 123, 5, 202, 38, 147, 118, 126, 255, 82,
85, 212, 207, 206, 59, 227, 47, 16, 58, 17, 182, 189, 28, 42, 223, 183, 170, 213, 119, 248, 152, 2, 44,
154, 163, 70, 221, 153, 101, 155, 167, 43, 172, 9, 129, 22, 39, 253, 19, 98, 108, 110, 79, 113, 224, 232,
178, 185, 112, 104, 218, 246, 97, 228, 251, 34, 242, 193, 238, 210, 144, 12, 191, 179, 162, 241, 81, 51,
145, 235, 249, 14, 239, 107, 49, 192, 214, 31, 181, 199, 106, 157, 184, 84, 204, 176, 115, 121, 50, 45,
127, 4, 150, 254, 138, 236, 205, 93, 222, 114, 67, 29, 24, 72, 243, 141, 128, 195, 78, 66, 215, 61, 156, 180
];
for (var i = 0; i < 256; i++) {
p[256 + i] = p[i] = permutation[i];
}
return {
/** Returns a number between 0 and 1. */
noise3d: function(x, y, z)
{
// Find unit cube that contains point.
var X = Math.floor(x) & 255,
Y = Math.floor(y) & 255,
Z = Math.floor(z) & 255;
// Find relative x,y,z of point in cube.
x -= Math.floor(x);
y -= Math.floor(y);
z -= Math.floor(z);
// Compute fade curves for each of x,y,z.
var u = fade(x),
v = fade(y),
w = fade(z);
// Hash coordinates of the corners.
var A = p[X ] + Y, AA = p[A] + Z, AB = p[A + 1] + Z,
B = p[X + 1] + Y, BA = p[B] + Z, BB = p[B + 1] + Z;
// Add blended results from 8 corners of cube.
return scale(
lerp(
w,
lerp(
v,
lerp(
u,
grad(p[AA], x, y, z),
grad(p[BA], x - 1, y, z)
),
lerp(
u,
grad(p[AB], x, y - 1, z),
grad(p[BB], x - 1, y - 1, z)
)
),
lerp(
v,
lerp(
u,
grad(p[AA + 1], x, y, z - 1),
grad(p[BA + 1], x - 1, y, z - 1)
),
lerp(
u,
grad(p[AB + 1], x, y - 1, z - 1),
grad(p[BB + 1], x - 1, y - 1, z - 1)
)
)
)
);
},
/** Returns a number between 0 and 1. */
noise2d: function(x, y)
{
// Find unit square that contains point.
var X = Math.floor(x) & 255,
Y = Math.floor(y) & 255;
// Find relative x,y of point in square.
x -= Math.floor(x);
y -= Math.floor(y);
// Compute fade curves for each of x,y.
var u = fade(x),
v = fade(y);
// Hash coordinates of the corners.
var A = p[X ] + Y, AA = p[A], AB = p[A + 1],
B = p[X + 1] + Y, BA = p[B], BB = p[B + 1];
// Add blended results from the corners.
return scale(
lerp(
v,
lerp(
u,
grad(p[AA], x, y, 0),
grad(p[BA], x - 1, y, 0)
),
lerp(
u,
grad(p[AB], x, y - 1, 0),
grad(p[BB], x - 1, y - 1, 0)
)
)
);
}
};
}
);
我提出了這個解決方案,它為我的用例提供了更好的結果:
http://asserttrue.blogspot.com/2011/12/perlin-noise-in-javascript_31.html
它使用了一個大的排列矩陣:
var permutation = [ 151,160,137,91,90,15,
131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23,
190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33,
88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166,
77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244,
102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196,
135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123,
5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42,
223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9,
129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228,
251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107,
49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254,
138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180
];
用它作為:
pn = PerlinNoise()
n = pn.noise( random_x, random_y, .8 )
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