commentsrefactoring

1 files changed, 33 insertions, 13 deletions

diff --git a/Scripts/cloth.js b/Scripts/cloth.js
index 1f1c1e0..712ed63 100644
--- a/Scripts/cloth.js
+++ b/Scripts/cloth.js
@@ -5,10 +5,6 @@ const GRAVITY = new THREE.Vector3(0, -9.81 * MASS, 0);
 const K = 1;

 const MAX_STRETCH = 1.5;

 

-// Explosion am Anfang

-// Intersect mit Velocity?

-// Wind/Ziehen

-

 const options = {

   wind: true,

 };

@@ -21,22 +17,23 @@ class Spring {
   }

 

   satisfy() {

+    /** calculate current spring length */

     const diff = this.p2.position.clone().sub(this.p1.position);

     const currentDist = diff.length();

     if (currentDist == 0) return;

     if (currentDist <= this.restDist) return;

     //const correction = diff.multiplyScalar(1 - (this.restDist / currentDist));

+

+    /** calculate necessary correction length and direction */

     const correction = diff.multiplyScalar((currentDist - this.restDist) / currentDist);

     correction.multiplyScalar(K);

-    if (currentDist >= this.restDist * MAX_STRETCH) {

-

-    }

-    //correction.clampLength(0, 1);

     const correctionHalf = correction.multiplyScalar(0.5);

 

     let p1movable = this.p1.movable && this.p1.movableTmp;

     let p2movable = this.p2.movable && this.p2.movableTmp;

 

+    /** apply correction if masses aren't fixed */

+    /** divide correction if both are movable */

     if (p1movable && p2movable) {

       this.p1.position.add(correctionHalf);

       this.p2.position.sub(correctionHalf);

@@ -67,8 +64,11 @@ class Mass {
     // verlet algorithm

     // next position = 2 * current Position - previous position + acceleration * (passed time)^2

     // acceleration (dv/dt) = F(net)

+    /** calculate velocity */

     const nextPosition = this.position.clone().sub(this.previous);

+    /** apply drag */

     nextPosition.multiplyScalar(DRAG);

+    /** add to current position and add acceleration */

     nextPosition.add(this.position);

     nextPosition.add(this.acceleration.multiplyScalar(dt*dt));

 

@@ -77,6 +77,7 @@ class Mass {
       this.position = nextPosition;

     }

 

+    /** reset for next frame */

     this.acceleration.set(0, 0, 0);

   }

 }

@@ -114,18 +115,16 @@ class Cloth {
       }

     }

 

-    //this.masses[this.getVertexIndex(0, 0)].movable = false;

+    /** attach cloth to flag pole */

     const n = 3;

     for (let i = 0; i < numPointsHeight; i++)

       this.masses[this.getVertexIndex(0, i)].movable = false;

-    //this.masses[this.getVertexIndex(0, numPointsHeight-1)].movable = false;

-    //this.masses[this.getVertexIndex(numPointsWidth-1, 0)].movable = false;

 

     const REST_DIST_X = width / (numPointsWidth-1);

     const REST_DIST_Y = height / (numPointsHeight-1);

 

     /**

-     * generate springs (springs)

+     * generate springs (constraints)

      */

     this.springs = [];

     for (let y = 0; y < numPointsHeight; y++) {

@@ -154,6 +153,7 @@ class Cloth {
     const indices = [];

     const uvs = [];

 

+    /** create one vertex and one uv coordinate per mass */

     for (let i in this.masses) {

       let particle = this.masses[i];

       vertices.push(

@@ -185,6 +185,7 @@ class Cloth {
       }

     }

 

+    /** set up geometry */

     geometry.setIndex(indices);

     geometry.setAttribute('position', new THREE.Float32BufferAttribute(vertices, 3));

     geometry.setAttribute('uv', new THREE.Float32BufferAttribute(uvs, 2));

@@ -194,6 +195,7 @@ class Cloth {
     return geometry;

   }

   updateGeometry(geometry) {

+    /** update vertex positions in place */

     const positions = geometry.attributes.position.array;

     for (let i in this.masses) {

       let p = this.masses[i];

@@ -201,6 +203,7 @@ class Cloth {
       positions[i*3+1] = p.position.y;

       positions[i*3+2] = p.position.z;

     }

+    /** update internally and recalculate bounding volume */

     geometry.attributes.position.needsUpdate = true;

     geometry.computeBoundingSphere();

     geometry.computeVertexNormals();

@@ -208,6 +211,10 @@ class Cloth {
   simulate(dt) {

     let now = performance.now();

     for (let mass of this.masses) {

+      /** accumulate acceleration:

+       *  - wind

+       *  - gravity

+       */

       let vertex = mass.position;

       let fWind = new THREE.Vector3(

         this.windFactor.x * (Math.sin(vertex.x * vertex.y * now)+1),

@@ -221,14 +228,16 @@ class Cloth {
 

       mass.addForce(GRAVITY);

 

+      /** integrate motion */

       mass.verlet(dt);

     }

 

-    

+    /** run satisfy step */

     for (let constraint of this.springs) {

       constraint.satisfy();

     }

 

+    /** prevent self-intersections */

     this.intersect();

   }

 

@@ -241,15 +250,21 @@ class Cloth {
         p1.movableTmp = true;

         p2.movableTmp = true;

 

+        /** skip if i == j or if masses are adjacent */

         if (i == j || (Math.abs(this.getX(i) - this.getX(j)) == 1 && Math.abs(this.getY(i) - this.getY(j)) == 1))

           continue;

 

+        /** calculate distance of points  */

         let dist = p1.position.distanceTo(p2.position);

+        /** calculate minimal resting distance (largest distance that should not be fallen below) */

         let collisionDistance = Math.min(this.width / this.numPointsWidth, this.height / this.numPointsHeight);

         // collisionDistance /= 2;

+        /** calculate "sphere intersection" */

         if (dist < collisionDistance) {

           // p1.movableTmp = false;

           // p2.movableTmp = false;

+

+          /** vectors from p1 to p2 and the other way round */

           let diffP2P1 = p1.position.clone().sub(p2.position).normalize();

           diffP2P1.multiplyScalar((collisionDistance - dist) * 1.001 / 2);

           let diffP1P2 = diffP2P1.clone().multiplyScalar(-1);

@@ -260,6 +275,7 @@ class Cloth {
           // let factor1 = (Math.PI - Math.acos(v1.dot(diffP2P1))) / Math.PI * 2;

           // let factor2 = (Math.PI - Math.acos(v2.dot(diffP1P2))) / Math.PI * 2;

 

+          /** move masses apart */

           if (p1.movable)

             p1.position.add(diffP2P1);

             //p1.position.add(diffP2P1.multiplyScalar(factor1));

@@ -272,13 +288,17 @@ class Cloth {
   }

   blow(camPos, intersects) {

     let face = intersects[0].face;

+    /** vector from cam to intersection (wind) */

     let dir = intersects[0].point.clone().sub(camPos).multiplyScalar(100);

+    /** apply to all vertices of affected face */

     this.masses[face.a].addForce(dir);

     this.masses[face.b].addForce(dir);

     this.masses[face.c].addForce(dir);

   }

   drag(mousePosWorld, index) {

+    /** calculate vector from vertex to cursor */

     let dir = mousePosWorld.clone().sub(this.masses[index].position).multiplyScalar(200);

+    /** apply to grabbed vertex */

     this.masses[index].addForce(dir);

   }