X-Git-Url: https://gitweb.ps.run/cloth_sim/blobdiff_plain/f97f4ee25759ffaa6a4d4709f45fc8b7b5b24973..959c350fb8cddf7d1b31907fcc1f7f99dad52f3e:/Scripts/cloth.js

diff --git a/Scripts/cloth.js b/Scripts/cloth.js
deleted file mode 100644
index 712ed63..0000000
--- a/Scripts/cloth.js
+++ /dev/null
@@ -1,317 +0,0 @@
-const DAMPING = 0.03;
-const DRAG = 1 - DAMPING;
-const MASS = 0.1;
-const GRAVITY = new THREE.Vector3(0, -9.81 * MASS, 0);
-const K = 1;
-const MAX_STRETCH = 1.5;
-
-const options = {
-  wind: true,
-};
-
-class Spring {
-  constructor(p1, p2, restDist) {
-    this.p1 = p1;
-    this.p2 = p2;
-    this.restDist = restDist;
-  }
-
-  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);
-    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);
-    } else if (! p1movable && p2movable) {
-      this.p2.position.sub(correction);
-    } else if (p1movable && ! p2movable) {
-      this.p1.position.add(correction);
-    }
-  }
-}
-
-class Mass {
-  movableTmp = true;
-  movable = true;
-
-  constructor(x, y, z, mass) {
-    this.position = new THREE.Vector3(x, y, z);
-    this.previous = new THREE.Vector3(x, y, z);
-    this.acceleration = new THREE.Vector3(0, 0, 0);
-    this.mass = mass;
-  }
-  addForce(force) {
-    this.acceleration.add(
-      force.clone().multiplyScalar(1/this.mass)
-    );
-  }
-  verlet(dt) {
-    // 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));
-
-    if (this.movable && this.movableTmp) {
-      this.previous = this.position;
-      this.position = nextPosition;
-    }
-
-    /** reset for next frame */
-    this.acceleration.set(0, 0, 0);
-  }
-}
-
-class Cloth {
-  constructor(width, height, numPointsWidth, numPointsHeight) {
-    this.width = width;
-    this.height = height;
-    this.numPointsWidth = numPointsWidth;
-    this.numPointsHeight = numPointsHeight;
-    this.windFactor = new THREE.Vector3(3, 2, 2);
-
-    /**
-     * distance between two vertices horizontally/vertically
-     * divide by the number of points minus one
-     * because there are (n - 1) lines between n vertices
-     */
-    let stepWidth = width / (numPointsWidth - 1);
-    let stepHeight = height / (numPointsHeight - 1);
-
-    /**
-     * iterate over the number of vertices in x/y axis
-     * and add a new Particle to "masses"
-     */
-    this.masses = [];
-    for (let y = 0; y < numPointsHeight; y++) {
-      for (let x = 0; x < numPointsWidth; x++) {
-        this.masses.push(
-          new Mass(
-            (x - ((numPointsWidth-1)/2)) * stepWidth,
-            height - (y + ((numPointsHeight-1)/2)) * stepHeight,
-            0,
-            MASS)
-        );
-      }
-    }
-
-    /** attach cloth to flag pole */
-    const n = 3;
-    for (let i = 0; i < numPointsHeight; i++)
-      this.masses[this.getVertexIndex(0, i)].movable = false;
-
-    const REST_DIST_X = width / (numPointsWidth-1);
-    const REST_DIST_Y = height / (numPointsHeight-1);
-
-    /**
-     * generate springs (constraints)
-     */
-    this.springs = [];
-    for (let y = 0; y < numPointsHeight; y++) {
-      for (let x = 0; x < numPointsWidth; x++) {
-        if (x < numPointsWidth-1) {
-          this.springs.push(new Spring(
-            this.masses[this.getVertexIndex(x, y)],
-            this.masses[this.getVertexIndex(x+1, y)],
-            REST_DIST_X
-          ));
-        }
-        if (y < numPointsHeight-1) {
-          this.springs.push(new Spring(
-            this.masses[this.getVertexIndex(x, y)],
-            this.masses[this.getVertexIndex(x, y+1)],
-            REST_DIST_Y
-          ));
-        }
-      }
-    }
-  }
-  generateGeometry() {
-    const geometry = new THREE.BufferGeometry();
-
-    const vertices = [];
-    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(
-        particle.position.x,
-        particle.position.y,
-        particle.position.z);
-      uvs.push(
-        this.getX(i) / (this.numPointsWidth-1),
-        1 - (this.getY(i) / (this.numPointsHeight-1))
-      );
-    }
-
-    /**
-     * generate faces based on 4 vertices
-     * and 6 springs each
-     */
-    for (let y = 0; y < this.numPointsHeight - 1; y++) {
-      for (let x = 0; x < this.numPointsWidth - 1; x++) {
-        indices.push(
-          this.getVertexIndex(x, y),
-          this.getVertexIndex(x+1, y),
-          this.getVertexIndex(x+1, y+1)
-        );
-        indices.push(
-          this.getVertexIndex(x, y),
-          this.getVertexIndex(x+1, y+1),
-          this.getVertexIndex(x, y+1)
-        );
-      }
-    }
-
-    /** set up geometry */
-    geometry.setIndex(indices);
-    geometry.setAttribute('position', new THREE.Float32BufferAttribute(vertices, 3));
-    geometry.setAttribute('uv', new THREE.Float32BufferAttribute(uvs, 2));
-    geometry.computeBoundingSphere();
-    geometry.computeVertexNormals();
-
-    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];
-      positions[i*3+0] = p.position.x;
-      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();
-  }
-  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),
-        this.windFactor.y * Math.cos(vertex.z * now),
-        this.windFactor.z * Math.sin(Math.cos(5 * vertex.x * vertex.y * vertex.z))
-      );
-      // normalize then multiply?
-      if (options.wind)
-        mass.addForce(fWind);
-      // calculate wind with normal?
-
-      mass.addForce(GRAVITY);
-
-      /** integrate motion */
-      mass.verlet(dt);
-    }
-
-    /** run satisfy step */
-    for (let constraint of this.springs) {
-      constraint.satisfy();
-    }
-
-    /** prevent self-intersections */
-    this.intersect();
-  }
-
-  intersect() {
-    for (let i in this.masses) {
-      for (let j in this.masses) {  
-        let p1 = this.masses[i];
-        let p2 = this.masses[j];
-
-        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);
-
-          // let v1 = p1.position.clone().sub(p1.previous).normalize();
-          // let v2 = p2.position.clone().sub(p2.previous).normalize();
-
-          // 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));
-          if (p2.movable)
-            p2.position.add(diffP1P2);
-            //p2.position.add(diffP1P2.multiplyScalar(factor2));
-        }
-      }
-    }
-  }
-  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);
-  }
-
-  /**
-   * helper function to calculate index of vertex
-   * in "vertices" array based on its x and y positions
-   * in the mesh
-   * @param {number} x - x index of vertex
-   * @param {number} y - y index of vertex
-   */
-  getVertexIndex(x, y) {
-    return y * this.numPointsWidth + x;
-  }
-  getX(i) { return i % this.numPointsWidth; }
-  getY(i) { return Math.floor(i / this.numPointsWidth); }
-}
\ No newline at end of file