From: Patrick Schönberger <patrick.schoenberger@posteo.de>
Date: Fri, 22 Jan 2021 15:48:29 +0000 (+0100)
Subject: fix verlet integration, add wind
X-Git-Url: https://gitweb.ps.run/cloth_sim/commitdiff_plain/590349d576668595128e2d15bbd72e9391a97fc1

fix verlet integration, add wind
---

diff --git a/Scripts/cloth.js b/Scripts/cloth.js
index 038b235..266af16 100644
--- a/Scripts/cloth.js
+++ b/Scripts/cloth.js
@@ -373,7 +373,7 @@ getAcceleration(vertexIndex, dt) {
   // constant gravity
   let g = new THREE.Vector3(0, -9.8, 0);
   // stiffness
-  let k = 500;
+  let k = 1000;
 
   // Wind vector
   let fWind = new THREE.Vector3(
@@ -381,13 +381,12 @@ getAcceleration(vertexIndex, dt) {
     Math.cos(vertex.z * this.time),
     Math.sin(Math.cos(5 * vertex.x * vertex.y * vertex.z))
   );
-  fWind.set(0, 0, 0);
 
   /**
    * constant determined by the properties of the surrounding fluids (air)
    * achievement of cloth effects through try out
    * */
-  let a = 0.01;
+  let a = 0.1;
   
   let velocity = new THREE.Vector3(
     (this.previousPositions[vertexIndex].x - vertex.x) / dt,
@@ -490,13 +489,19 @@ verlet(currentPosition, previousPosition, acceleration, passedTime) {
   // next position = 2 * current Position - previous position + acceleration * (passed time)^2
   // acceleration (dv/dt) = F(net)
   // Dependency for one vertex: gravity, fluids/air, springs
-
+  const DRAG = 0.97;
   let nextPosition = new THREE.Vector3(
-    (2 * currentPosition.x) - previousPosition.x + acceleration.x * (passedTime * passedTime),
-    (2 * currentPosition.y) - previousPosition.y + acceleration.y * (passedTime * passedTime),
-    (2 * currentPosition.z) - previousPosition.z + acceleration.z * (passedTime * passedTime),
+    (currentPosition.x - previousPosition.x) * DRAG + currentPosition.x + acceleration.x * (passedTime * passedTime),
+    (currentPosition.y - previousPosition.y) * DRAG + currentPosition.y + acceleration.y * (passedTime * passedTime),
+    (currentPosition.z - previousPosition.z) * DRAG + currentPosition.z + acceleration.z * (passedTime * passedTime),
   );
 
+  // let nextPosition = new THREE.Vector3(
+  //   (2 * currentPosition.x) - previousPosition.x + acceleration.x * (passedTime * passedTime),
+  //   (2 * currentPosition.y) - previousPosition.y + acceleration.y * (passedTime * passedTime),
+  //   (2 * currentPosition.z) - previousPosition.z + acceleration.z * (passedTime * passedTime),
+  // );
+
   return nextPosition;
 }
 
@@ -510,5 +515,12 @@ euler(currentPosition, acceleration, passedTime) {
   return nextPosition;
 }
 
+wind(intersects) {
+  let intersect = intersects[0];
+  this.geometry.vertices[intersect.face.a].z -= 0.05;
+  this.geometry.vertices[intersect.face.b].z -= 0.05;
+  this.geometry.vertices[intersect.face.c].z -= 0.05;
+}
+
 }
 
diff --git a/Scripts/main.js b/Scripts/main.js
index 4e7c2ef..20a6e92 100644
--- a/Scripts/main.js
+++ b/Scripts/main.js
@@ -8,35 +8,6 @@ import { Face, Spring, Cloth } from './cloth.js';
  * evtl. an Stoff ziehen
  */
 
-
-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)
-  }
-}
-
-
 /**
  * setup THREE JS Scene, Camera and Renderer
  */
@@ -64,7 +35,7 @@ function setup_scene(canvasSpace) {
 document.body.onload = init;
 
 function init() {
-  let mousePos = new Point();
+  let mousePos = new THREE.Vector2();
   let previousClothSimulation;
   
   /**
@@ -99,6 +70,8 @@ function init() {
   const light = new THREE.DirectionalLight( 0xffffff, 0.5 );
   light.position.set( 0, 1, 0.5 );
   scene.add( light );
+  
+  let raycaster = new THREE.Raycaster();
 
   /**
    * function called every frame
@@ -107,17 +80,27 @@ function init() {
   function animate(dt) {
     cloth.simulate(dt/1000);
 
+    raycaster.setFromCamera( new THREE.Vector2((mousePos.x / w) * 2 - 1, ((h - mousePos.y) / h) * 2 - 1), camera );
+
+    const intersects = raycaster.intersectObject( mesh );
+
+    if ( intersects.length > 0 ) {
+      cloth.wind(intersects);
+    }
     setTimeout(() => {
       animate(frameTime);
     }, frameTime);
     renderer.render(scene, camera);
   }
 
+
   /** add callback for window resize */
   let canvas = document.getElementsByTagName("canvas")[0];
+  let w = window.innerWidth;
+  let h = window.innerHeight - canvasSpace;
   let resize = function () {
-    let w = window.innerWidth;
-    let h = window.innerHeight - 200;
+    w = window.innerWidth;
+    h = window.innerHeight - canvasSpace;
     canvas.width = w;
     canvas.height = h;
   }