enable cloth-cloth collision

[cloth_sim] / Scripts / cloth.js

diff --git a/Scripts/cloth.js b/Scripts/cloth.js
index 05ff6f1f30eb54da8985b99c786d3596662f214e..1f1c1e01df19a910b5911c12ef95669b0576173e 100644 (file)
--- a/Scripts/cloth.js
+++ b/Scripts/cloth.js
@@ -1,10 +1,57 @@
-// cloth rendering\r
-// simulate\r
-// setup scene\r
-\r
+const DAMPING = 0.03;\r
+const DRAG = 1 - DAMPING;\r

 const MASS = 0.1;\r
 const MASS = 0.1;\r

+const GRAVITY = new THREE.Vector3(0, -9.81 * MASS, 0);\r
+const K = 1;\r
+const MAX_STRETCH = 1.5;\r
+\r
+// Explosion am Anfang\r
+// Intersect mit Velocity?\r
+// Wind/Ziehen\r
+\r
+const options = {\r
+  wind: true,\r
+};\r
+\r
+class Spring {\r
+  constructor(p1, p2, restDist) {\r
+    this.p1 = p1;\r
+    this.p2 = p2;\r
+    this.restDist = restDist;\r
+  }\r
+\r
+  satisfy() {\r
+    const diff = this.p2.position.clone().sub(this.p1.position);\r
+    const currentDist = diff.length();\r
+    if (currentDist == 0) return;\r
+    if (currentDist <= this.restDist) return;\r
+    //const correction = diff.multiplyScalar(1 - (this.restDist / currentDist));\r
+    const correction = diff.multiplyScalar((currentDist - this.restDist) / currentDist);\r
+    correction.multiplyScalar(K);\r
+    if (currentDist >= this.restDist * MAX_STRETCH) {\r
+\r
+    }\r
+    //correction.clampLength(0, 1);\r
+    const correctionHalf = correction.multiplyScalar(0.5);\r
+\r
+    let p1movable = this.p1.movable && this.p1.movableTmp;\r
+    let p2movable = this.p2.movable && this.p2.movableTmp;\r
+\r
+    if (p1movable && p2movable) {\r
+      this.p1.position.add(correctionHalf);\r
+      this.p2.position.sub(correctionHalf);\r
+    } else if (! p1movable && p2movable) {\r
+      this.p2.position.sub(correction);\r
+    } else if (p1movable && ! p2movable) {\r
+      this.p1.position.add(correction);\r
+    }\r
+  }\r
+}\r
+\r
+class Mass {\r
+  movableTmp = true;\r
+  movable = true;\r

 \r
 \r

-class Particle {\r

   constructor(x, y, z, mass) {\r
     this.position = new THREE.Vector3(x, y, z);\r
     this.previous = new THREE.Vector3(x, y, z);\r
   constructor(x, y, z, mass) {\r
     this.position = new THREE.Vector3(x, y, z);\r
     this.previous = new THREE.Vector3(x, y, z);\r


@@ -12,10 +59,25 @@ class Particle {
     this.mass = mass;\r
   }\r
   addForce(force) {\r
     this.mass = mass;\r
   }\r
   addForce(force) {\r

-\r
+    this.acceleration.add(\r
+      force.clone().multiplyScalar(1/this.mass)\r
+    );\r

   }\r
   verlet(dt) {\r
   }\r
   verlet(dt) {\r

+    // verlet algorithm\r
+    // next position = 2 * current Position - previous position + acceleration * (passed time)^2\r
+    // acceleration (dv/dt) = F(net)\r
+    const nextPosition = this.position.clone().sub(this.previous);\r
+    nextPosition.multiplyScalar(DRAG);\r
+    nextPosition.add(this.position);\r
+    nextPosition.add(this.acceleration.multiplyScalar(dt*dt));\r
+\r
+    if (this.movable && this.movableTmp) {\r
+      this.previous = this.position;\r
+      this.position = nextPosition;\r
+    }\r

 \r
 \r

+    this.acceleration.set(0, 0, 0);\r

   }\r
 }\r
 \r
   }\r
 }\r
 \r


@@ -25,6 +87,7 @@ class Cloth {
     this.height = height;\r
     this.numPointsWidth = numPointsWidth;\r
     this.numPointsHeight = numPointsHeight;\r
     this.height = height;\r
     this.numPointsWidth = numPointsWidth;\r
     this.numPointsHeight = numPointsHeight;\r

+    this.windFactor = new THREE.Vector3(3, 2, 2);\r

 \r
     /**\r
      * distance between two vertices horizontally/vertically\r
 \r
     /**\r
      * distance between two vertices horizontally/vertically\r


@@ -36,13 +99,13 @@ class Cloth {
 \r
     /**\r
      * iterate over the number of vertices in x/y axis\r
 \r
     /**\r
      * iterate over the number of vertices in x/y axis\r

-     * and add a new Particle to "particles"\r
+     * and add a new Particle to "masses"\r

      */\r
      */\r

-    this.particles = [];\r
+    this.masses = [];\r

     for (let y = 0; y < numPointsHeight; y++) {\r
       for (let x = 0; x < numPointsWidth; x++) {\r
     for (let y = 0; y < numPointsHeight; y++) {\r
       for (let x = 0; x < numPointsWidth; x++) {\r

-        this.particles.push(\r
-          new Particle(\r
+        this.masses.push(\r
+          new Mass(\r

             (x - ((numPointsWidth-1)/2)) * stepWidth,\r
             height - (y + ((numPointsHeight-1)/2)) * stepHeight,\r
             0,\r
             (x - ((numPointsWidth-1)/2)) * stepWidth,\r
             height - (y + ((numPointsHeight-1)/2)) * stepHeight,\r
             0,\r


@@ -50,63 +113,185 @@ class Cloth {
         );\r
       }\r
     }\r
         );\r
       }\r
     }\r

+\r
+    //this.masses[this.getVertexIndex(0, 0)].movable = false;\r
+    const n = 3;\r
+    for (let i = 0; i < numPointsHeight; i++)\r
+      this.masses[this.getVertexIndex(0, i)].movable = false;\r
+    //this.masses[this.getVertexIndex(0, numPointsHeight-1)].movable = false;\r
+    //this.masses[this.getVertexIndex(numPointsWidth-1, 0)].movable = false;\r
+\r
+    const REST_DIST_X = width / (numPointsWidth-1);\r
+    const REST_DIST_Y = height / (numPointsHeight-1);\r
+\r
+    /**\r
+     * generate springs (springs)\r
+     */\r
+    this.springs = [];\r
+    for (let y = 0; y < numPointsHeight; y++) {\r
+      for (let x = 0; x < numPointsWidth; x++) {\r
+        if (x < numPointsWidth-1) {\r
+          this.springs.push(new Spring(\r
+            this.masses[this.getVertexIndex(x, y)],\r
+            this.masses[this.getVertexIndex(x+1, y)],\r
+            REST_DIST_X\r
+          ));\r
+        }\r
+        if (y < numPointsHeight-1) {\r
+          this.springs.push(new Spring(\r
+            this.masses[this.getVertexIndex(x, y)],\r
+            this.masses[this.getVertexIndex(x, y+1)],\r
+            REST_DIST_Y\r
+          ));\r
+        }\r
+      }\r
+    }\r

   }\r
   generateGeometry() {\r
     const geometry = new THREE.BufferGeometry();\r
 \r
     const vertices = [];\r
   }\r
   generateGeometry() {\r
     const geometry = new THREE.BufferGeometry();\r
 \r
     const vertices = [];\r

-    const normals = [];\r

     const indices = [];\r
     const indices = [];\r

+    const uvs = [];\r

 \r
 \r

-    for (let particle of this.particles) {\r
+    for (let i in this.masses) {\r
+      let particle = this.masses[i];\r

       vertices.push(\r
         particle.position.x,\r
         particle.position.y,\r
         particle.position.z);\r
       vertices.push(\r
         particle.position.x,\r
         particle.position.y,\r
         particle.position.z);\r

-    }\r
-\r
-    const numPointsWidth = this.numPointsWidth;\r
-    const numPointsHeight = this.numPointsHeight;\r
-\r
-    /**\r
-     * helper function to calculate index of vertex\r
-     * in "vertices" array based on its x and y positions\r
-     * in the mesh\r
-     * @param {number} x - x index of vertex\r
-     * @param {number} y - y index of vertex\r
-     */\r
-    function getVertexIndex(x, y) {\r
-      return y * numPointsWidth + x;\r
+      uvs.push(\r
+        this.getX(i) / (this.numPointsWidth-1),\r
+        1 - (this.getY(i) / (this.numPointsHeight-1))\r
+      );\r

     }\r
 \r
     /**\r
      * generate faces based on 4 vertices\r
      * and 6 springs each\r
      */\r
     }\r
 \r
     /**\r
      * generate faces based on 4 vertices\r
      * and 6 springs each\r
      */\r

-    for (let y = 0; y < numPointsHeight - 1; y++) {\r
-      for (let x = 0; x < numPointsWidth - 1; x++) {\r
+    for (let y = 0; y < this.numPointsHeight - 1; y++) {\r
+      for (let x = 0; x < this.numPointsWidth - 1; x++) {\r

         indices.push(\r
         indices.push(\r

-          getVertexIndex(x, y),\r
-          getVertexIndex(x+1, y),\r
-          getVertexIndex(x+1, y+1)\r
+          this.getVertexIndex(x, y),\r
+          this.getVertexIndex(x+1, y),\r
+          this.getVertexIndex(x+1, y+1)\r

         );\r
         indices.push(\r
         );\r
         indices.push(\r

-          getVertexIndex(x, y),\r
-          getVertexIndex(x+1, y+1),\r
-          getVertexIndex(x, y+1)\r
+          this.getVertexIndex(x, y),\r
+          this.getVertexIndex(x+1, y+1),\r
+          this.getVertexIndex(x, y+1)\r

         );\r
       }\r
     }\r
 \r
     geometry.setIndex(indices);\r
     geometry.setAttribute('position', new THREE.Float32BufferAttribute(vertices, 3));\r
         );\r
       }\r
     }\r
 \r
     geometry.setIndex(indices);\r
     geometry.setAttribute('position', new THREE.Float32BufferAttribute(vertices, 3));\r

-    //geometry.setAttribute('normal', new THREE.Float32BufferAttribute(normals, 3));\r
+    geometry.setAttribute('uv', new THREE.Float32BufferAttribute(uvs, 2));\r

     geometry.computeBoundingSphere();\r
     geometry.computeVertexNormals();\r
 \r
     return geometry;\r
   }\r
   updateGeometry(geometry) {\r
     geometry.computeBoundingSphere();\r
     geometry.computeVertexNormals();\r
 \r
     return geometry;\r
   }\r
   updateGeometry(geometry) {\r

+    const positions = geometry.attributes.position.array;\r
+    for (let i in this.masses) {\r
+      let p = this.masses[i];\r
+      positions[i*3+0] = p.position.x;\r
+      positions[i*3+1] = p.position.y;\r
+      positions[i*3+2] = p.position.z;\r
+    }\r
+    geometry.attributes.position.needsUpdate = true;\r
+    geometry.computeBoundingSphere();\r
+    geometry.computeVertexNormals();\r
+  }\r
+  simulate(dt) {\r
+    let now = performance.now();\r
+    for (let mass of this.masses) {\r
+      let vertex = mass.position;\r
+      let fWind = new THREE.Vector3(\r
+        this.windFactor.x * (Math.sin(vertex.x * vertex.y * now)+1),\r
+        this.windFactor.y * Math.cos(vertex.z * now),\r
+        this.windFactor.z * Math.sin(Math.cos(5 * vertex.x * vertex.y * vertex.z))\r
+      );\r
+      // normalize then multiply?\r
+      if (options.wind)\r
+        mass.addForce(fWind);\r
+      // calculate wind with normal?\r
+\r
+      mass.addForce(GRAVITY);\r
+\r
+      mass.verlet(dt);\r
+    }\r
+\r
+    \r
+    for (let constraint of this.springs) {\r
+      constraint.satisfy();\r
+    }\r
+\r
+    this.intersect();\r
+  }\r
+\r
+  intersect() {\r
+    for (let i in this.masses) {\r
+      for (let j in this.masses) {  \r
+        let p1 = this.masses[i];\r
+        let p2 = this.masses[j];\r
+\r
+        p1.movableTmp = true;\r
+        p2.movableTmp = true;\r
+\r
+        if (i == j || (Math.abs(this.getX(i) - this.getX(j)) == 1 && Math.abs(this.getY(i) - this.getY(j)) == 1))\r
+          continue;\r
+\r
+        let dist = p1.position.distanceTo(p2.position);\r
+        let collisionDistance = Math.min(this.width / this.numPointsWidth, this.height / this.numPointsHeight);\r
+        // collisionDistance /= 2;\r
+        if (dist < collisionDistance) {\r
+          // p1.movableTmp = false;\r
+          // p2.movableTmp = false;\r
+          let diffP2P1 = p1.position.clone().sub(p2.position).normalize();\r
+          diffP2P1.multiplyScalar((collisionDistance - dist) * 1.001 / 2);\r
+          let diffP1P2 = diffP2P1.clone().multiplyScalar(-1);\r
+\r
+          // let v1 = p1.position.clone().sub(p1.previous).normalize();\r
+          // let v2 = p2.position.clone().sub(p2.previous).normalize();\r
+\r
+          // let factor1 = (Math.PI - Math.acos(v1.dot(diffP2P1))) / Math.PI * 2;\r
+          // let factor2 = (Math.PI - Math.acos(v2.dot(diffP1P2))) / Math.PI * 2;\r
+\r
+          if (p1.movable)\r
+            p1.position.add(diffP2P1);\r
+            //p1.position.add(diffP2P1.multiplyScalar(factor1));\r
+          if (p2.movable)\r
+            p2.position.add(diffP1P2);\r
+            //p2.position.add(diffP1P2.multiplyScalar(factor2));\r
+        }\r
+      }\r
+    }\r
+  }\r
+  blow(camPos, intersects) {\r
+    let face = intersects[0].face;\r
+    let dir = intersects[0].point.clone().sub(camPos).multiplyScalar(100);\r
+    this.masses[face.a].addForce(dir);\r
+    this.masses[face.b].addForce(dir);\r
+    this.masses[face.c].addForce(dir);\r
+  }\r
+  drag(mousePosWorld, index) {\r
+    let dir = mousePosWorld.clone().sub(this.masses[index].position).multiplyScalar(200);\r
+    this.masses[index].addForce(dir);\r
+  }\r

 \r
 \r

+  /**\r
+   * helper function to calculate index of vertex\r
+   * in "vertices" array based on its x and y positions\r
+   * in the mesh\r
+   * @param {number} x - x index of vertex\r
+   * @param {number} y - y index of vertex\r
+   */\r
+  getVertexIndex(x, y) {\r
+    return y * this.numPointsWidth + x;\r

   }\r
   }\r

+  getX(i) { return i % this.numPointsWidth; }\r
+  getY(i) { return Math.floor(i / this.numPointsWidth); }\r

 }
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 }
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