Updating threejs geometry vertices with time

I have a SphereGeometrythat im trying to update it's vertices based on the current performance.now() value, with perlin noise involved.

SphereGeometry

performance.now()

I'm expecting a result like so:

Here's my working example:
http://jsfiddle.net/8L4bktyw/1/

But for some reason, the vertices are not being updated (at least visually), but the colors on the MeshNormalMaterial change as if they are changed.

MeshNormalMaterial

The strange thing is that if you refresh / run the fiddle consecutively, you'll see the vertices change. Just as expected.

Am i updating the geometry incorrectly?

1 Answer
1

But for some reason, the vertices are not being updated

You told the normal vectors to be updated:

sphere.geometry.normalsNeedUpdate = true;


But you missed to update the vertex coordinates, too:

sphere.geometry.verticesNeedUpdate = true;


See THREE.Geometry

See the Example, where the suggestion of the answer is applied to the original code of your question:

var renderer = new THREE.WebGLRenderer({ canvas : document.getElementById('myCanvas'), antialias:true});
renderer.setClearColor(0x7b7b7b);
renderer.setPixelRatio(window.devicePixelRatio);
renderer.setSize(window.innerWidth, window.innerHeight);

var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera( 45, window.innerWidth/window.innerHeight, 0.1, 1000 );
camera.position.z = 5;

var sphere_geometry = new THREE.SphereGeometry(1, 128, 128);
var material = new THREE.MeshNormalMaterial();

var sphere = new THREE.Mesh(sphere_geometry, material);
scene.add(sphere);
window.onresize = resize;

var update = function() {

var time = performance.now() * 0.003;

//go through vertices here and reposition them
var k = 3;
for (var i = 0; i < sphere.geometry.vertices.length; i++) {
var p = sphere.geometry.vertices[i];
p.normalize().multiplyScalar(1 + 0.3 * noise.perlin3(p.x * k + time, p.y * k, p.z * k));
}
sphere.geometry.computeVertexNormals();
sphere.geometry.normalsNeedUpdate = true;
sphere.geometry.verticesNeedUpdate = true;
}

function resize() {

var aspect = window.innerWidth / window.innerHeight;
renderer.setSize(window.innerWidth, window.innerHeight);
camera.aspect = aspect;
camera.updateProjectionMatrix();
//controls.handleResize();
}

function animate() {
//sphere.rotation.x += 0.01;
//sphere.rotation.y += 0.01;

update();
/* render scene and camera */
renderer.render(scene,camera);
requestAnimationFrame(animate);
}

requestAnimationFrame(animate);

(function(global){
var module = global.noise = {};

function Grad(x, y, z) {
this.x = x; this.y = y; this.z = z;
}

Grad.prototype.dot2 = function(x, y) {
return this.x*x + this.y*y;
};

Grad.prototype.dot3 = function(x, y, z) {
return this.x*x + this.y*y + this.z*z;
};

var grad3 = [new Grad(1,1,0),new Grad(-1,1,0),new Grad(1,-1,0),new Grad(-1,-1,0),
new Grad(1,0,1),new Grad(-1,0,1),new Grad(1,0,-1),new Grad(-1,0,-1),
new Grad(0,1,1),new Grad(0,-1,1),new Grad(0,1,-1),new Grad(0,-1,-1)];

var p = [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];
// To remove the need for index wrapping, double the permutation table length
var perm = new Array(512);
var gradP = new Array(512);

// This isn't a very good seeding function, but it works ok. It supports 2^16
// different seed values. Write something better if you need more seeds.
module.seed = function(seed) {
if(seed > 0 && seed < 1) {
// Scale the seed out
seed *= 65536;
}

seed = Math.floor(seed);
if(seed < 256) {
seed |= seed << 8;
}

for(var i = 0; i < 256; i++) {
var v;
if (i & 1) {
v = p[i] ^ (seed & 255);
} else {
v = p[i] ^ ((seed>>8) & 255);
}

perm[i] = perm[i + 256] = v;
gradP[i] = gradP[i + 256] = grad3[v % 12];
}
};

module.seed(0);

/*
for(var i=0; i<256; i++) {
perm[i] = perm[i + 256] = p[i];
gradP[i] = gradP[i + 256] = grad3[perm[i] % 12];
}*/

// Skewing and unskewing factors for 2, 3, and 4 dimensions
var F2 = 0.5*(Math.sqrt(3)-1);
var G2 = (3-Math.sqrt(3))/6;

var F3 = 1/3;
var G3 = 1/6;

// 2D simplex noise
module.simplex2 = 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 s = (xin+yin)*F2; // Hairy factor for 2D
var i = Math.floor(xin+s);
var j = Math.floor(yin+s);
var t = (i+j)*G2;
var x0 = xin-i+t; // The x,y distances from the cell origin, unskewed.
var y0 = yin-j+t;
// 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) { // lower triangle, XY order: (0,0)->(1,0)->(1,1)
i1=1; j1=0;
} else { // upper triangle, YX order: (0,0)->(0,1)->(1,1)
i1=0; j1=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 + 2 * G2; // Offsets for last corner in (x,y) unskewed coords
var y2 = y0 - 1 + 2 * G2;
// Work out the hashed gradient indices of the three simplex corners
i &= 255;
j &= 255;
var gi0 = gradP[i+perm[j]];
var gi1 = gradP[i+i1+perm[j+j1]];
var gi2 = gradP[i+1+perm[j+1]];
// Calculate the contribution from the three corners
var t0 = 0.5 - x0*x0-y0*y0;
if(t0<0) {
n0 = 0;
} else {
t0 *= t0;
n0 = t0 * t0 * gi0.dot2(x0, y0); // (x,y) of grad3 used for 2D gradient
}
var t1 = 0.5 - x1*x1-y1*y1;
if(t1<0) {
n1 = 0;
} else {
t1 *= t1;
n1 = t1 * t1 * gi1.dot2(x1, y1);
}
var t2 = 0.5 - x2*x2-y2*y2;
if(t2<0) {
n2 = 0;
} else {
t2 *= t2;
n2 = t2 * t2 * gi2.dot2(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 * (n0 + n1 + n2);
};

// 3D simplex noise
module.simplex3 = 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 s = (xin+yin+zin)*F3; // Hairy factor for 2D
var i = Math.floor(xin+s);
var j = Math.floor(yin+s);
var k = Math.floor(zin+s);

var t = (i+j+k)*G3;
var x0 = xin-i+t; // The x,y distances from the cell origin, unskewed.
var y0 = yin-j+t;
var z0 = zin-k+t;

// 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; }
else if(x0 >= z0) { i1=1; j1=0; k1=0; i2=1; j2=0; k2=1; }
else { i1=0; j1=0; k1=1; i2=1; j2=0; k2=1; }
} else {
if(y0 < z0) { i1=0; j1=0; k1=1; i2=0; j2=1; k2=1; }
else if(x0 < z0) { i1=0; j1=1; k1=0; i2=0; j2=1; k2=1; }
else { i1=0; j1=1; k1=0; i2=1; j2=1; k2=0; }
}
// 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
var y1 = y0 - j1 + G3;
var z1 = z0 - k1 + G3;

var x2 = x0 - i2 + 2 * G3; // Offsets for third corner
var y2 = y0 - j2 + 2 * G3;
var z2 = z0 - k2 + 2 * G3;

var x3 = x0 - 1 + 3 * G3; // Offsets for fourth corner
var y3 = y0 - 1 + 3 * G3;
var z3 = z0 - 1 + 3 * G3;

// Work out the hashed gradient indices of the four simplex corners
i &= 255;
j &= 255;
k &= 255;
var gi0 = gradP[i+ perm[j+ perm[k ]]];
var gi1 = gradP[i+i1+perm[j+j1+perm[k+k1]]];
var gi2 = gradP[i+i2+perm[j+j2+perm[k+k2]]];
var gi3 = gradP[i+ 1+perm[j+ 1+perm[k+ 1]]];

// Calculate the contribution from the four corners
var t0 = 0.6 - x0*x0 - y0*y0 - z0*z0;
if(t0<0) {
n0 = 0;
} else {
t0 *= t0;
n0 = t0 * t0 * gi0.dot3(x0, y0, z0); // (x,y) of grad3 used for 2D gradient
}
var t1 = 0.6 - x1*x1 - y1*y1 - z1*z1;
if(t1<0) {
n1 = 0;
} else {
t1 *= t1;
n1 = t1 * t1 * gi1.dot3(x1, y1, z1);
}
var t2 = 0.6 - x2*x2 - y2*y2 - z2*z2;
if(t2<0) {
n2 = 0;
} else {
t2 *= t2;
n2 = t2 * t2 * gi2.dot3(x2, y2, z2);
}
var t3 = 0.6 - x3*x3 - y3*y3 - z3*z3;
if(t3<0) {
n3 = 0;
} else {
t3 *= t3;
n3 = t3 * t3 * gi3.dot3(x3, y3, z3);
}
// Add contributions from each corner to get the final noise value.
// The result is scaled to return values in the interval [-1,1].
return 32 * (n0 + n1 + n2 + n3);

};

// ##### Perlin noise stuff

function fade(t) {
return t*t*t*(t*(t*6-15)+10);
}

function lerp(a, b, t) {
return (1-t)*a + t*b;
}

// 2D Perlin Noise
module.perlin2 = function(x, y) {
// Find unit grid cell containing point
var X = Math.floor(x), Y = Math.floor(y);
// Get relative xy coordinates of point within that cell
x = x - X; y = y - Y;
// Wrap the integer cells at 255 (smaller integer period can be introduced here)
X = X & 255; Y = Y & 255;

// Calculate noise contributions from each of the four corners
var n00 = gradP[X+perm[Y]].dot2(x, y);
var n01 = gradP[X+perm[Y+1]].dot2(x, y-1);
var n10 = gradP[X+1+perm[Y]].dot2(x-1, y);
var n11 = gradP[X+1+perm[Y+1]].dot2(x-1, y-1);

// Compute the fade curve value for x
var u = fade(x);

// Interpolate the four results
return lerp(
lerp(n00, n10, u),
lerp(n01, n11, u),
fade(y));
};

// 3D Perlin Noise
module.perlin3 = function(x, y, z) {
// Find unit grid cell containing point
var X = Math.floor(x), Y = Math.floor(y), Z = Math.floor(z);
// Get relative xyz coordinates of point within that cell
x = x - X; y = y - Y; z = z - Z;
// Wrap the integer cells at 255 (smaller integer period can be introduced here)
X = X & 255; Y = Y & 255; Z = Z & 255;

// Calculate noise contributions from each of the eight corners
var n000 = gradP[X+ perm[Y+ perm[Z ]]].dot3(x, y, z);
var n001 = gradP[X+ perm[Y+ perm[Z+1]]].dot3(x, y, z-1);
var n010 = gradP[X+ perm[Y+1+perm[Z ]]].dot3(x, y-1, z);
var n011 = gradP[X+ perm[Y+1+perm[Z+1]]].dot3(x, y-1, z-1);
var n100 = gradP[X+1+perm[Y+ perm[Z ]]].dot3(x-1, y, z);
var n101 = gradP[X+1+perm[Y+ perm[Z+1]]].dot3(x-1, y, z-1);
var n110 = gradP[X+1+perm[Y+1+perm[Z ]]].dot3(x-1, y-1, z);
var n111 = gradP[X+1+perm[Y+1+perm[Z+1]]].dot3(x-1, y-1, z-1);

// Compute the fade curve value for x, y, z
var u = fade(x);
var v = fade(y);
var w = fade(z);

// Interpolate
return lerp(
lerp(
lerp(n000, n100, u),
lerp(n001, n101, u), w),
lerp(
lerp(n010, n110, u),
lerp(n011, n111, u), w),
v);
};

})(this);

<script src="https://threejs.org/build/three.min.js"></script>
<canvas id="myCanvas"></canvas>

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