From: Patrick Schönberger <patrick.schoenberger@posteo.de>
Date: Sat, 6 Feb 2021 12:25:24 +0000 (+0100)
Subject: tweaking parameters
X-Git-Url: https://gitweb.ps.run/cloth_sim/commitdiff_plain/56f6324db4aa55946a6b5ef7de3e1df8b0e22bca?ds=inline

tweaking parameters
---

diff --git a/Scripts/cloth.js b/Scripts/cloth.js
index 0c4f02c..aaa9d24 100644
--- a/Scripts/cloth.js
+++ b/Scripts/cloth.js
@@ -1,10 +1,12 @@
 const DAMPING = 0.03;
 const DRAG = 1 - DAMPING;
-const MASS = 0.1;
+const MASS = 0.35;
 const GRAVITY = new THREE.Vector3(0, -9.81 * MASS, 0);
 const K = 1;
 
-let tmpCorrection;
+const options = {
+  wind: true,
+};
 
 class Constraint {
   constructor(p1, p2, restDist) {
@@ -18,12 +20,19 @@ class Constraint {
     const currentDist = diff.length();
     if (currentDist == 0) return;
     if (currentDist <= this.restDist) return;
-    const correction = diff.multiplyScalar(1 - (this.restDist / currentDist));
+    //const correction = diff.multiplyScalar(1 - (this.restDist / currentDist));
+    const correction = diff.multiplyScalar((currentDist - this.restDist) / currentDist);
     correction.multiplyScalar(K);
-    tmpCorrection = correction;
+    correction.clampLength(0, 1);
     const correctionHalf = correction.multiplyScalar(0.5);
-    this.p1.position.add(correctionHalf);
-    this.p2.position.sub(correctionHalf);
+    if (this.p1.movable && this.p2.movable) {
+      this.p1.position.add(correctionHalf);
+      this.p2.position.sub(correctionHalf);
+    } else if (! this.p1.movable && this.p2.movable) {
+      this.p2.position.sub(correction);
+    } else if (this.p1.movable && ! this.p2.movable) {
+      this.p1.position.add(correction);
+    }
   }
 }
 
@@ -50,8 +59,10 @@ class Particle {
     nextPosition.add(this.position);
     nextPosition.add(this.acceleration.multiplyScalar(dt*dt));
 
-    this.previous = this.position;
-    this.position = nextPosition;
+    if (this.movable) {
+      this.previous = this.position;
+      this.position = nextPosition;
+    }
 
     this.acceleration.set(0, 0, 0);
   }
@@ -63,7 +74,7 @@ class Cloth {
     this.height = height;
     this.numPointsWidth = numPointsWidth;
     this.numPointsHeight = numPointsHeight;
-    this.windFactor = new THREE.Vector3(0.5, 0.2, 0.2);
+    this.windFactor = new THREE.Vector3(5, 2, 2);
 
     /**
      * distance between two vertices horizontally/vertically
@@ -90,9 +101,12 @@ class Cloth {
       }
     }
 
-    this.particles[this.getVertexIndex(0, 0)].movable = false;
-    this.particles[this.getVertexIndex(0, numPointsHeight-1)].movable = false;
-    this.particles[this.getVertexIndex(numPointsWidth-1, 0)].movable = false;
+    //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;
+    //this.particles[this.getVertexIndex(0, numPointsHeight-1)].movable = false;
+    //this.particles[this.getVertexIndex(numPointsWidth-1, 0)].movable = false;
 
     const REST_DIST_X = width / (numPointsWidth-1);
     const REST_DIST_Y = height / (numPointsHeight-1);
@@ -168,13 +182,9 @@ class Cloth {
     const positions = geometry.attributes.position.array;
     for (let i in this.particles) {
       let p = this.particles[i];
-      if (p.movable) {
-        positions[i*3+0] = p.position.x;
-        positions[i*3+1] = p.position.y;
-        positions[i*3+2] = p.position.z;
-      } else {
-        p.position = p.previous;
-      }
+      positions[i*3+0] = p.position.x;
+      positions[i*3+1] = p.position.y;
+      positions[i*3+2] = p.position.z;
     }
     geometry.attributes.position.needsUpdate = true;
     geometry.computeBoundingSphere();
@@ -190,7 +200,8 @@ class Cloth {
         this.windFactor.z * Math.sin(Math.cos(5 * vertex.x * vertex.y * vertex.z))
       );
       // normalize then multiply?
-      particle.addForce(fWind);
+      if (options.wind)
+        particle.addForce(fWind);
       // calculate wind with normal?
 
       particle.addForce(GRAVITY);
diff --git a/Scripts/main.js b/Scripts/main.js
index 3353f4d..7611601 100644
--- a/Scripts/main.js
+++ b/Scripts/main.js
@@ -75,7 +75,7 @@ function init() {
   const canvasSpace = 200;
 
   /** Constant Frame Time */
-  const frameTime = 1000.0 / 60.0;
+  const frameTime = 1000.0 / 200.0;
 
   /** Setup scene */
   let [scene, camera, renderer] = setup_scene(canvasSpace);
@@ -83,7 +83,7 @@ function init() {
   //const loader = new THREE.TextureLoader();
   //Red color: 0xC70039
 
-  const cloth = new Cloth(1, 0.5, 20, 10);
+  const cloth = new Cloth(1, 0.5, 40, 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 });