Genuary 13: Just Triangles

mySketch
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let font
let pipe
​
function preload() {
  font = loadFont('https://fonts.gstatic.com/s/sacramento/v15/buEzpo6gcdjy0EiZMBUG0CoV_NxLeiw.ttf')
}
​
function setup() {
  createCanvas(windowWidth, windowHeight, WEBGL)
  
  pipe = buildGeometry(() => {
    const path = BezierPath.create([
      {
        pt: { x: -200, y: -50 },
        right: { x: -100, y: -50 }
      },
      {
        left: { x: -50, y: 50 },
        pt: { x: 50, y: 50 },
        right: { x: 100, y: 50 }
      },
      {
        left: { x: 120, y: 50 },
        pt: { x: 120, y: -70 }
      }
    ])
    
    const numPoints = 50
    const pts = []
    const tangents = []
    for (let i = 0; i <= numPoints; i++) {
      const len = map(i, 0, numPoints, 0, path.getTotalLength())
      const pt = path.getPointAtLength(len)
      const tan = path.getTangentAtLength(len)
      pts.push(createVector(pt.x, pt.y, 0))
      tangents.push(createVector(tan.x, tan.y))
    }
    const normals = tangents.map((t) => t.copy().cross(createVector(0, 0, 1)))
    
    const getR = (i) => lerp(10, 40, map(i, numPoints*0.1, numPoints*0.8, 0, 1, true))
    const circlePoints = 30
    
    for (let i = 0; i < numPoints; i++) {
      beginShape(TRIANGLE_STRIP)
      for (let j = 0; j <= circlePoints; j++) {
        const angle = j/circlePoints * TWO_PI
        for (let off of [0, 1]) {
          const r = getR(i+off)
          const c = pts[i+off]
          const n1 = createVector(0, 0, 1)
          const n2 = normals[i + off]
          const pt = c.copy().add(n2.copy().mult(sin(angle)*r)).add(n1.copy().mult(cos(angle)*r))
          vertex(pt.x, pt.y, pt.z)
        }
      }
      endShape()
    }
  })
}
​
function draw() {
  background(255)
  
  // orbitControl()
  
  push()
  scale(1.5)
  strokeWeight(2)
  rotateX(sin(millis() * 0.001) * PI * 0.1)
  rotateY(sin(millis() * 0.0021) * PI * 0.025)
  model(pipe)
  pop()
  
  clearDepth()
  push()
  textAlign(CENTER, BOTTOM)
  textFont(font)
  textSize(80)
  fill(0)
  text(`Ceci n'est pas une pipe.`, 0, height * 0.4)
  pop()
}