Method saveStl

src/webgl/p5.Geometry.js:466–526

* The `saveStl()` function exports `p5.Geometry` objects as * 3D models in the STL stereolithography file format. * This way, you can use the 3D shapes you create in p5.js in other software * for rendering, animation, 3D printing, or more. * * The exported .stl file will include the f

(fileName = 'model.stl', { binary = false } = {})

   * }
   */
  saveStl(fileName = 'model.stl', { binary = false } = {}){
    let modelOutput;
    let name = fileName.substring(0, fileName.lastIndexOf('.'));
    let faceNormals = [];
    for (let f of this.faces) {
      const U = Vector.sub(this.vertices[f[1]], this.vertices[f[0]]);
      const V = Vector.sub(this.vertices[f[2]], this.vertices[f[0]]);
      const nx = U.y * V.z - U.z * V.y;
      const ny = U.z * V.x - U.x * V.z;
      const nz = U.x * V.y - U.y * V.x;
      faceNormals.push(new Vector(nx, ny, nz).normalize());
    }
    if (binary) {
      let offset = 80;
      const bufferLength =
        this.faces.length * 2 + this.faces.length * 3 * 4 * 4 + 80 + 4;
      const arrayBuffer = new ArrayBuffer(bufferLength);
      modelOutput = new DataView(arrayBuffer);
      modelOutput.setUint32(offset, this.faces.length, true);
      offset += 4;
      for (const [key, f] of Object.entries(this.faces)) {
        const norm = faceNormals[key];
        modelOutput.setFloat32(offset, norm.x, true);
        offset += 4;
        modelOutput.setFloat32(offset, norm.y, true);
        offset += 4;
        modelOutput.setFloat32(offset, norm.z, true);
        offset += 4;
        for (let vertexIndex of f) {
          const vert = this.vertices[vertexIndex];
          modelOutput.setFloat32(offset, vert.x, true);
          offset += 4;
          modelOutput.setFloat32(offset, vert.y, true);
          offset += 4;
          modelOutput.setFloat32(offset, vert.z, true);
          offset += 4;
        }
        modelOutput.setUint16(offset, 0, true);
        offset += 2;
      }
    } else {
      modelOutput = 'solid ' + name + '\n';

      for (const [key, f] of Object.entries(this.faces)) {
        const norm = faceNormals[key];
        modelOutput +=
          ' facet norm ' + norm.x + ' ' + norm.y + ' ' + norm.z + '\n';
        modelOutput += '  outer loop' + '\n';
        for (let vertexIndex of f) {
          const vert = this.vertices[vertexIndex];
          modelOutput +=
            '   vertex ' + vert.x + ' ' + vert.y + ' ' + vert.z + '\n';
        }
        modelOutput += '  endloop' + '\n';
        modelOutput += ' endfacet' + '\n';
      }
      modelOutput += 'endsolid ' + name + '\n';
    }