From: Patrick Schönberger <patrick.schoenberger@posteo.de>
Date: Mon, 1 Feb 2021 13:08:56 +0000 (+0100)
Subject: cloth-cloth collision
X-Git-Url: https://gitweb.ps.run/cloth_sim/commitdiff_plain/8ecb6f064f0708ed010f1239a7bddc283411b6e7

cloth-cloth collision
---

diff --git a/Scripts/cloth.js b/Scripts/cloth.js
index 1ec79d5..0708d5e 100644
--- a/Scripts/cloth.js
+++ b/Scripts/cloth.js
@@ -98,8 +98,10 @@ export class Cloth {
 
   vertexRigidness = [];
 
+  fixedPoints = [];
+
   externalForces = [];
-  windForce = 100;
+  windForce = 50;
 
   /**
    * creates a rectangular piece of cloth
@@ -133,7 +135,7 @@ export class Cloth {
     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)
+          new THREE.Vector3((x - (numPointsWidth/2)) * stepWidth, height - y * stepHeight, 0)
         );
       }
     }
@@ -182,8 +184,10 @@ export class Cloth {
     /**
      * hand cloth from left and right upper corners
      */
-    this.vertexRigidness[0] = true;
-    this.vertexRigidness[numPointsWidth-1] = true;
+    //this.vertexRigidness[0] = true;
+    //this.vertexRigidness[numPointsWidth * (numPointsHeight - 1)] = true;
+    this.fixedPoints.push(getVertexIndex(8, 10));
+    this.fixedPoints.push(getVertexIndex(12, 9));
   }
 
   /**
@@ -341,7 +345,8 @@ export class Cloth {
       this.previousPositions[i].copy(this.geometry.vertices[i]);
       this.geometry.vertices[i].copy(currentPosition);
     }
-    //console.log(this.getAcceleration(1, dt));
+    
+    this.checkIntersect();
     
     this.time += dt;
 
@@ -364,7 +369,31 @@ export class Cloth {
 
   }
 
-
+checkIntersect() {
+  let npw = this.numPointsWidth;
+  function getX(i, ) { return i % npw; }
+  function getY(i) { return Math.floor(i / npw); }
+  for (let i in this.geometry.vertices) {
+    for (let j in this.geometry.vertices) {
+      this.vertexRigidness[i] = false;
+      this.vertexRigidness[j] = false;
+      if (i == j || (Math.abs(getX(i) - getX(j)) == 1 && Math.abs(getY(i) - getY(j)) == 1))
+        continue;
+      let posI = this.geometry.vertices[i];
+      let posJ = this.geometry.vertices[j];
+      let dist = posI.distanceTo(posJ);
+      const collisionDistance = 0.5;
+      if (dist < collisionDistance) {
+        this.vertexRigidness[i] = true;
+        this.vertexRigidness[j] = true;
+        let diff = this.geometry.vertices[i].clone().sub(this.geometry.vertices[j]).normalize().multiplyScalar((collisionDistance - dist) * 1.001 / 2);
+        this.geometry.vertices[i].add(diff);
+        this.geometry.vertices[j].sub(diff);
+        console.log(this.geometry.vertices[i].distanceTo(this.geometry.vertices[j]));
+      }
+    }
+  }
+}
 
 /**
  * Equation of motion for each vertex which represents the acceleration 
@@ -372,8 +401,10 @@ export class Cloth {
  *  @param {number} dt The time passed since last frame
  */
 getAcceleration(vertexIndex, dt) {
-  if (this.vertexRigidness[vertexIndex])
+  if (this.fixedPoints.includes(parseInt(vertexIndex)) ||
+      this.vertexRigidness[vertexIndex]) {
     return new THREE.Vector3(0, 0, 0);
+  }
 
   let externalForce = this.externalForces[vertexIndex];
   let vertex = this.geometry.vertices[vertexIndex];//.add(externalForce);
@@ -383,7 +414,7 @@ getAcceleration(vertexIndex, dt) {
   // constant gravity
   let g = new THREE.Vector3(0, -9.8, 0);
   // stiffness
-  let k = 1000;
+  let k = 500;
 
   // Wind vector
   let fWind = new THREE.Vector3(
diff --git a/Scripts/main.js b/Scripts/main.js
index 01e3283..588e8f1 100644
--- a/Scripts/main.js
+++ b/Scripts/main.js
@@ -35,7 +35,7 @@ function setup_scene(canvasSpace) {
   scene.add(directionalLight);
 
   /** position camera */
-  camera.position.y = 5;
+  camera.position.y = 3;
   camera.position.z = 10;
   addLights(scene);
   return [scene, camera, renderer];
@@ -62,7 +62,7 @@ function init() {
   
   /** setup cloth and generate debug mesh */
   let cloth = new Cloth();
-  cloth.createBasic(10, 10, 10, 10);
+  cloth.createBasic(10, 10, 20, 20);
   //cloth.createDebugMesh(scene);