我想创建一个带有three.js 和单纯形噪声的地形生成器，但我不知道如何根据它们的生物群系为平面上的顶点着色。这是我的代码：
document.addEventListener("DOMContentLoaded", function(){
var noise = new SimplexNoise();
var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 1, 100000);
var renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
camera.position.z = 100;
var width, height, resolution, maxHeight, cameraDist;
/*
*/
//write code here
width = 100;
height = 100;
resolution = 50;
maxHeight = 10;
cameraDist = 1000;
//write code here
/*
*/
var geometry = new THREE.PlaneGeometry(width, height, resolution, resolution);
var light = new THREE.DirectionalLight(0xFFFFFF, 5);
scene.add(light);
light.position.y = 10;
var mat = new THREE.MeshBasicMaterial({color: 0xffffff});
var xOff = 0.0;
let i = 0;
const WATER = "rgb(0, 0, 255)";
const WOODLAND = 0x3f2a14;
const MOUNTAIN = "rgb(200, 200, 200)";
const SNOW = "rgb(255, 255, 255)";
for (let x = 0; x <= width; x += width / resolution){
let yOff = 0.0;
for (let y = 0; y <= height; y += height / resolution){
let microHills = 0.03125 * noise.noise(32 * xOff, 32 * yOff)
let extremelytinyHills = 0.0625 * noise.noise(16 * xOff, 16 * yOff);
let verytinyHills = 0.125 * noise.noise(8 * xOff, 8 * yOff);
let tinyHills = 0.25 * noise.noise(4 * xOff, 4 * yOff);
let mediumHills = 0.5 * noise.noise(2 * xOff, 2 * yOff);
let largeHills = noise.noise(xOff, yOff);
let z = (microHills + extremelytinyHills + verytinyHills + tinyHills + mediumHills + largeHills) * maxHeight;
geometry.vertices[i].z = z;
let biome;
if(Math.random() < 0.2){
biome = WATER;
}
else if(Math.random() < 0.5){
biome = WOODLAND;
}
else if(Math.random() < 0.6){
biome = MOUNTAIN;
}
else if(Math.random() > 0.8){
biome = SNOW;
}
//color???
mat[i] = new THREE.MeshBasicMaterial({color: biome});
yOff ++;
i ++;
}
xOff ++;
}
var Mesh = new THREE.Mesh(geometry, mat);
var controls = new THREE.OrbitControls(camera, renderer.domElement);
controls.enableDamping = true;
controls.dampingFactor = 0.25;
controls.enableZoom = true;
controls.autoRotate = true;
scene.add(Mesh);
function loop(){
renderer.render(scene, camera);
requestAnimationFrame(loop);
};
requestAnimationFrame(loop);
});<script src="https://gist.githubusercontent.com/heisters/1146b7f20149e1e3925b/raw/c5d6028df20a20e339bf8c9e1708422c42779495/three.orbitcontrols.js"></script>
<script src="https://threejs.org/build/three.min.js"></script>
<script>// Ported from Stefan Gustavson's java implementation
// http://staffwww.itn.liu.se/~stegu/simplexnoise/simplexnoise.pdf
// Read Stefan's excellent paper for details on how this code works.
//
// Sean McCullough banksean@gmail.com
/**
* You can pass in a random number generator object if you like.
* It is assumed to have a random() method.
*/
var SimplexNoise = function(r) {
if (r == undefined) r = Math;
this.grad3 = [[1,1,0],[-1,1,0],[1,-1,0],[-1,-1,0],
[1,0,1],[-1,0,1],[1,0,-1],[-1,0,-1],
[0,1,1],[0,-1,1],[0,1,-1],[0,-1,-1]];
this.p = [];
for (var i=0; i<256; i++) {
this.p[i] = Math.floor(r.random()*256);
}
// To remove the need for index wrapping, double the permutation table length
this.perm = [];
for(var i=0; i<512; i++) {
this.perm[i]=this.p[i & 255];
}
// A lookup table to traverse the simplex around a given point in 4D.
// Details can be found where this table is used, in the 4D noise method.
this.simplex = [
[0,1,2,3],[0,1,3,2],[0,0,0,0],[0,2,3,1],[0,0,0,0],[0,0,0,0],[0,0,0,0],[1,2,3,0],
[0,2,1,3],[0,0,0,0],[0,3,1,2],[0,3,2,1],[0,0,0,0],[0,0,0,0],[0,0,0,0],[1,3,2,0],
[0,0,0,0],[0,0,0,0],[0,0,0,0],[0,0,0,0],[0,0,0,0],[0,0,0,0],[0,0,0,0],[0,0,0,0],
[1,2,0,3],[0,0,0,0],[1,3,0,2],[0,0,0,0],[0,0,0,0],[0,0,0,0],[2,3,0,1],[2,3,1,0],
[1,0,2,3],[1,0,3,2],[0,0,0,0],[0,0,0,0],[0,0,0,0],[2,0,3,1],[0,0,0,0],[2,1,3,0],
[0,0,0,0],[0,0,0,0],[0,0,0,0],[0,0,0,0],[0,0,0,0],[0,0,0,0],[0,0,0,0],[0,0,0,0],
[2,0,1,3],[0,0,0,0],[0,0,0,0],[0,0,0,0],[3,0,1,2],[3,0,2,1],[0,0,0,0],[3,1,2,0],
[2,1,0,3],[0,0,0,0],[0,0,0,0],[0,0,0,0],[3,1,0,2],[0,0,0,0],[3,2,0,1],[3,2,1,0]];
this.dot = function(g, x, y) {
return g[0]*x + g[1]*y;
};
this.noise = function(xin, yin) {
var n0, n1, n2; // Noise contributions from the three corners
// Skew the input space to determine which simplex cell we're in
var F2 = 0.5*(Math.sqrt(3.0)-1.0);
var s = (xin+yin)*F2; // Hairy factor for 2D
var i = Math.floor(xin+s);
var j = Math.floor(yin+s);
var G2 = (3.0-Math.sqrt(3.0))/6.0;
var t = (i+j)*G2;
var X0 = i-t; // Unskew the cell origin back to (x,y) space
var Y0 = j-t;
var x0 = xin-X0; // The x,y distances from the cell origin
var y0 = yin-Y0;
// For the 2D case, the simplex shape is an equilateral triangle.
// Determine which simplex we are in.
var i1, j1; // Offsets for second (middle) corner of simplex in (i,j) coords
if(x0>y0) {i1=1; j1=0;} // lower triangle, XY order: (0,0)->(1,0)->(1,1)
else {i1=0; j1=1;} // upper triangle, YX order: (0,0)->(0,1)->(1,1)
// A step of (1,0) in (i,j) means a step of (1-c,-c) in (x,y), and
// a step of (0,1) in (i,j) means a step of (-c,1-c) in (x,y), where
// c = (3-sqrt(3))/6
var x1 = x0 - i1 + G2; // Offsets for middle corner in (x,y) unskewed coords
var y1 = y0 - j1 + G2;
var x2 = x0 - 1.0 + 2.0 * G2; // Offsets for last corner in (x,y) unskewed coords
var y2 = y0 - 1.0 + 2.0 * G2;
// Work out the hashed gradient indices of the three simplex corners
var ii = i & 255;
var jj = j & 255;
var gi0 = this.perm[ii+this.perm[jj]] % 12;
var gi1 = this.perm[ii+i1+this.perm[jj+j1]] % 12;
var gi2 = this.perm[ii+1+this.perm[jj+1]] % 12;
// Calculate the contribution from the three corners
var t0 = 0.5 - x0*x0-y0*y0;
if(t0<0) n0 = 0.0;
else {
t0 *= t0;
n0 = t0 * t0 * this.dot(this.grad3[gi0], x0, y0); // (x,y) of grad3 used for 2D gradient
}
var t1 = 0.5 - x1*x1-y1*y1;
if(t1<0) n1 = 0.0;
else {
t1 *= t1;
n1 = t1 * t1 * this.dot(this.grad3[gi1], x1, y1);
}
var t2 = 0.5 - x2*x2-y2*y2;
if(t2<0) n2 = 0.0;
else {
t2 *= t2;
n2 = t2 * t2 * this.dot(this.grad3[gi2], x2, y2);
}
// Add contributions from each corner to get the final noise value.
// The result is scaled to return values in the interval [-1,1].
return 70.0 * (n0 + n1 + n2);
};
// 3D simplex noise
this.noise3d = function(xin, yin, zin) {
var n0, n1, n2, n3; // Noise contributions from the four corners
// Skew the input space to determine which simplex cell we're in
var F3 = 1.0/3.0;
var s = (xin+yin+zin)*F3; // Very nice and simple skew factor for 3D
var i = Math.floor(xin+s);
var j = Math.floor(yin+s);
var k = Math.floor(zin+s);
var G3 = 1.0/6.0; // Very nice and simple unskew factor, too
var t = (i+j+k)*G3;
var X0 = i-t; // Unskew the cell origin back to (x,y,z) space
var Y0 = j-t;
var Z0 = k-t;
var x0 = xin-X0; // The x,y,z distances from the cell origin
var y0 = yin-Y0;
var z0 = zin-Z0;
// For the 3D case, the simplex shape is a slightly irregular tetrahedron.
// Determine which simplex we are in.
var i1, j1, k1; // Offsets for second corner of simplex in (i,j,k) coords
var i2, j2, k2; // Offsets for third corner of simplex in (i,j,k) coords
if(x0>=y0) {
if(y0>=z0)
{ i1=1; j1=0; k1=0; i2=1; j2=1; k2=0; } // X Y Z order
else if(x0>=z0) { i1=1; j1=0; k1=0; i2=1; j2=0; k2=1; } // X Z Y order
else { i1=0; j1=0; k1=1; i2=1; j2=0; k2=1; } // Z X Y order
}
else { // x0<y0
if(y0<z0) { i1=0; j1=0; k1=1; i2=0; j2=1; k2=1; } // Z Y X order
else if(x0<z0) { i1=0; j1=1; k1=0; i2=0; j2=1; k2=1; } // Y Z X order
else { i1=0; j1=1; k1=0; i2=1; j2=1; k2=0; } // Y X Z order
}
// A step of (1,0,0) in (i,j,k) means a step of (1-c,-c,-c) in (x,y,z),
// a step of (0,1,0) in (i,j,k) means a step of (-c,1-c,-c) in (x,y,z), and
// a step of (0,0,1) in (i,j,k) means a step of (-c,-c,1-c) in (x,y,z), where
// c = 1/6.
var x1 = x0 - i1 + G3; // Offsets for second corner in (x,y,z) coords
var y1 = y0 - j1 + G3;
var z1 = z0 - k1 + G3;
var x2 = x0 - i2 + 2.0*G3; // Offsets for third corner in (x,y,z) coords
var y2 = y0 - j2 + 2.0*G3;
var z2 = z0 - k2 + 2.0*G3;
var x3 = x0 - 1.0 + 3.0*G3; // Offsets for last corner in (x,y,z) coords
var y3 = y0 - 1.0 + 3.0*G3;
var z3 = z0 - 1.0 + 3.0*G3;
// Work out the hashed gradient indices of the four simplex corners
var ii = i & 255;
var jj = j & 255;
var kk = k & 255;
var gi0 = this.perm[ii+this.perm[jj+this.perm[kk]]] % 12;
var gi1 = this.perm[ii+i1+this.perm[jj+j1+this.perm[kk+k1]]] % 12;
var gi2 = this.perm[ii+i2+this.perm[jj+j2+this.perm[kk+k2]]] % 12;
var gi3 = this.perm[ii+1+this.perm[jj+1+this.perm[kk+1]]] % 12;
// Calculate the contribution from the four corners
var t0 = 0.6 - x0*x0 - y0*y0 - z0*z0;
if(t0<0) n0 = 0.0;
else {
t0 *= t0;
n0 = t0 * t0 * this.dot(this.grad3[gi0], x0, y0, z0);
}
var t1 = 0.6 - x1*x1 - y1*y1 - z1*z1;
if(t1<0) n1 = 0.0;
else {
t1 *= t1;
n1 = t1 * t1 * this.dot(this.grad3[gi1], x1, y1, z1);
}
var t2 = 0.6 - x2*x2 - y2*y2 - z2*z2;
if(t2<0) n2 = 0.0;
else {
t2 *= t2;
n2 = t2 * t2 * this.dot(this.grad3[gi2], x2, y2, z2);
}
var t3 = 0.6 - x3*x3 - y3*y3 - z3*z3;
if(t3<0) n3 = 0.0;
else {
t3 *= t3;
n3 = t3 * t3 * this.dot(this.grad3[gi3], x3, y3, z3);
}
// Add contributions from each corner to get the final noise value.
// The result is scaled to stay just inside [-1,1]
return 32.0*(n0 + n1 + n2 + n3);
};
};</script>这可行，但我想为各个顶点着色，因为您无法真正看到山脉的位置。如何为平面上的顶点着色？