From: Patrick Schönberger <patrick.schoenberger@posteo.de>
Date: Sat, 6 Feb 2021 12:43:39 +0000 (+0100)
Subject: add cloth-cloth collision
X-Git-Url: https://gitweb.ps.run/cloth_sim/commitdiff_plain/8199b09231f15b0f84480656a0e92827d795fcdc?hp=56f6324db4aa55946a6b5ef7de3e1df8b0e22bca

add cloth-cloth collision
---

diff --git a/Scripts/cloth.js b/Scripts/cloth.js
index aaa9d24..ff55549 100644
--- a/Scripts/cloth.js
+++ b/Scripts/cloth.js
@@ -1,6 +1,6 @@
 const DAMPING = 0.03;
 const DRAG = 1 - DAMPING;
-const MASS = 0.35;
+const MASS = 0.1;
 const GRAVITY = new THREE.Vector3(0, -9.81 * MASS, 0);
 const K = 1;
 
@@ -25,18 +25,23 @@ class Constraint {
     correction.multiplyScalar(K);
     correction.clampLength(0, 1);
     const correctionHalf = correction.multiplyScalar(0.5);
-    if (this.p1.movable && this.p2.movable) {
+
+    let p1movable = this.p1.movable && this.p1.movableTmp;
+    let p2movable = this.p2.movable && this.p2.movableTmp;
+
+    if (p1movable && p2movable) {
       this.p1.position.add(correctionHalf);
       this.p2.position.sub(correctionHalf);
-    } else if (! this.p1.movable && this.p2.movable) {
+    } else if (! p1movable && p2movable) {
       this.p2.position.sub(correction);
-    } else if (this.p1.movable && ! this.p2.movable) {
+    } else if (p1movable && ! p2movable) {
       this.p1.position.add(correction);
     }
   }
 }
 
 class Particle {
+  movableTmp = true;
   movable = true;
 
   constructor(x, y, z, mass) {
@@ -59,7 +64,7 @@ class Particle {
     nextPosition.add(this.position);
     nextPosition.add(this.acceleration.multiplyScalar(dt*dt));
 
-    if (this.movable) {
+    if (this.movable && this.movableTmp) {
       this.previous = this.position;
       this.position = nextPosition;
     }
@@ -74,7 +79,7 @@ class Cloth {
     this.height = height;
     this.numPointsWidth = numPointsWidth;
     this.numPointsHeight = numPointsHeight;
-    this.windFactor = new THREE.Vector3(5, 2, 2);
+    this.windFactor = new THREE.Vector3(3, 2, 2);
 
     /**
      * distance between two vertices horizontally/vertically
@@ -103,8 +108,8 @@ class Cloth {
 
     //this.particles[this.getVertexIndex(0, 0)].movable = false;
     const n = 3;
-    for (let i = 0; i <= n; i++)
-      this.particles[this.getVertexIndex(0, Math.floor((numPointsHeight-1)*(i/n)))].movable = false;
+    for (let i = 0; i < numPointsHeight; i++)
+      this.particles[this.getVertexIndex(0, i)].movable = false;
     //this.particles[this.getVertexIndex(0, numPointsHeight-1)].movable = false;
     //this.particles[this.getVertexIndex(numPointsWidth-1, 0)].movable = false;
 
@@ -213,8 +218,42 @@ class Cloth {
     for (let constraint of this.constraints) {
       constraint.satisfy();
     }
-    //console.log(tmpCorrection);
+
+    this.intersect();
+  }
+
+  intersect() {
+    let npw = this.numPointsWidth;
+    function getX(i) { return i % npw; }
+    function getY(i) { return Math.floor(i / npw); }
+
+    for (let i in this.particles) {
+      for (let j in this.particles) {  
+        let p1 = this.particles[i];
+        let p2 = this.particles[j];
+
+        p1.movableTmp = true;
+        p2.movableTmp = true;
+
+        if (i == j || (Math.abs(getX(i) - getX(j)) == 1 && Math.abs(getY(i) - getY(j)) == 1))
+          continue;
+
+        let dist = p1.position.distanceTo(p2.position);
+        const collisionDistance = Math.min(this.width / this.numPointsWidth, this.height / this.numPointsHeight);
+        if (dist < collisionDistance) {
+          p1.movableTmp = false;
+          p2.movableTmp = false;
+          let diff = p1.position.clone().sub(p2.position).normalize();
+          diff.multiplyScalar((collisionDistance - dist) * 1.001 / 2);
+          if (p1.movable)
+            p1.position.add(diff);
+          if (p2.movable)
+            p2.position.sub(diff);
+        }
+      }
+    }
   }
+
   /**
    * helper function to calculate index of vertex
    * in "vertices" array based on its x and y positions
diff --git a/Scripts/main.js b/Scripts/main.js
index 7611601..6fa9f22 100644
--- a/Scripts/main.js
+++ b/Scripts/main.js
@@ -83,13 +83,17 @@ function init() {
   //const loader = new THREE.TextureLoader();
   //Red color: 0xC70039
 
-  const cloth = new Cloth(1, 0.5, 40, 20);
+  const cloth = new Cloth(1, 0.5, 20, 20);
   const clothGeometry = cloth.generateGeometry();
   //const clothMaterial = new THREE.MeshStandardMaterial({ map: loader.load('Textures/DeutschlandFlagge.jpg'), color: 0xffffff, side: THREE.DoubleSide, flatShading: false});
   const clothMaterial = new THREE.MeshStandardMaterial({ color: 0xC70039, side: THREE.DoubleSide, flatShading: false });
   const clothMesh = new THREE.Mesh(clothGeometry, clothMaterial);
   scene.add(clothMesh);
   
+  document.getElementById("windToggle").onchange = (e) => {
+    options.wind = e.target.checked;
+  };
+
   let raycaster = new THREE.Raycaster();
   let intersects;
   let rightMousePressed;