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function init() {
class Point {
constructor(x, y) {
this.x = x;
this.y = y;
}
add(that) {
return new Point(
this.x + that.x,
this.y + that.y
);
}
sub(that) {
return new Point(
this.x - that.x,
this.y - that.y
);
}
dist(that) {
let a = this.x - that.x;
let b = this.y - that.y;
return Math.sqrt(a * a + b * b)
}
}
function vectorLength(a, b) {
let v1 = new THREE.Vector3();
v1.set(a.x, a.y, a.z);
let v2 = new THREE.Vector3();
v2.set(b.x, b.y, b.z);
return v1.sub(v2).length();
}
class Face {
a;
b;
c;
d;
springs = [];
constructor(a, b, c, d) {
this.a = a;
this.b = b;
this.c = c;
this.d = d;
}
}
class Spring {
restLength;
currentLength;
index1;
index2;
constructor(vertices, index1, index2) {
this.index1 = index1;
this.index2 = index2;
let length = vectorLength(vertices[index1], vertices[index2]);
this.restLength = length;
this.currentLength = length;
}
}
class Cloth {
VertexWeight = 1;
geometry = new THREE.Geometry();
faces = [];
vertexWeights = [];
static CreateBasic(width, height, numPointsWidth, numPointsHeight) {
let vertices = [];
let faces = [];
let stepWidth = width / (numPointsWidth - 1);
let stepHeight = height / (numPointsHeight - 1);
for (let y = 0; y < numPointsHeight; y++) {
for (let x = 0; x < numPointsWidth; x++) {
vertices.push(
new THREE.Vector3(x * stepWidth, height - y * stepHeight, 0)
);
}
}
function getVertexIndex(x, y) {
return y * numPointsWidth + x;
}
for (let y = 0; y < numPointsHeight - 1; y++) {
for (let x = 0; x < numPointsWidth - 1; x++) {
let newFace = new Face(
getVertexIndex(x, y),
getVertexIndex(x, y + 1),
getVertexIndex(x + 1, y),
getVertexIndex(x + 1, y + 1),
);
newFace.springs.push(new Spring(vertices, getVertexIndex(x, y), getVertexIndex(x + 1, y)));
newFace.springs.push(new Spring(vertices, getVertexIndex(x, y), getVertexIndex(x, y + 1)));
newFace.springs.push(new Spring(vertices, getVertexIndex(x, y), getVertexIndex(x + 1, y + 1)));
newFace.springs.push(new Spring(vertices, getVertexIndex(x + 1, y), getVertexIndex(x, y + 1)));
newFace.springs.push(new Spring(vertices, getVertexIndex(x + 1, y), getVertexIndex(x + 1, y + 1)));
newFace.springs.push(new Spring(vertices, getVertexIndex(x, y + 1), getVertexIndex(x + 1, y + 1)));
faces.push(newFace);
}
}
return this.CreateExplicit(vertices, faces);
}
static CreateExplicit(vertices, faces) {
let result = new Cloth();
for (let i in vertices) {
result.geometry.vertices.push(vertices[i]);
result.vertexWeights.push(0);
}
console.log(vertices);
for (let i in faces) {
let face = faces[i];
result.geometry.faces.push(new THREE.Face3(
face.a, face.b, face.c
));
result.geometry.faces.push(new THREE.Face3(
face.c, face.b, face.d
));
console.log(face);
let xLength = vectorLength(result.geometry.vertices[face.b], result.geometry.vertices[face.a]);
let yLength = vectorLength(result.geometry.vertices[face.c], result.geometry.vertices[face.a]);
let weight = xLength * yLength / 2;
xLength = vectorLength(result.geometry.vertices[face.b], result.geometry.vertices[face.d]);
yLength = vectorLength(result.geometry.vertices[face.c], result.geometry.vertices[face.d]);
weight += xLength * yLength / 2;
result.vertexWeights[face.a] += weight / 4;
result.vertexWeights[face.b] += weight / 4;
result.vertexWeights[face.c] += weight / 4;
result.vertexWeights[face.d] += weight / 4;
}
result.geometry.computeBoundingSphere();
return result;
}
}
let mousePos = new Point();
const canvasSpace = 200;
const scene = new THREE.Scene();
const camera = new THREE.PerspectiveCamera(75, window.innerWidth / (window.innerHeight - canvasSpace), 0.1, 1000);
const renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight - canvasSpace);
document.getElementById("threejscontainer").appendChild(renderer.domElement);
const directionalLight = new THREE.DirectionalLight(0xffffff, 1);
scene.add(directionalLight);
let cloth = Cloth.CreateBasic(10, 10, 5, 5);
const material = new THREE.MeshBasicMaterial({ color: 0x00ff00 });
const mesh = new THREE.Mesh(cloth.geometry, material);
scene.add(mesh);
camera.position.y = 5;
camera.position.z = 10;
function animate(dt) {
requestAnimationFrame(animate);
renderer.render(scene, camera);
}
let canvas = document.getElementsByTagName("canvas")[0];
let resize = function () {
w = window.innerWidth;
h = window.innerHeight - 200;
canvas.width = w;
canvas.height = h;
}
window.onresize = resize;
resize();
if (canvas.getContext) {
ctx = canvas.getContext('2d');
animate(performance.now());
}
canvas.onmousemove = (evt) => {
mousePos.x = evt.clientX;
mousePos.y = evt.clientY;
};
}
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