src/examples/railway-with-csg.html

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    <meta http-equiv="X-UA-Compatible" content="ie=edge" />
    <title>Railway with CSG and HACD</title>
    <link rel="stylesheet" href="/css/examples.css?ver=1.0.0" />
    <script src="/js/examples.js?ver=1.1.1"></script>
    <script src="/lib/enable3d/enable3d.framework.0.25.4.min.js"></script>
  </head>

  <body>
    <div id="info-text">Make a Railway using CSG and HACD Body</div>
    <script>
      const { Project, Scene3D, PhysicsLoader, ExtendedObject3D, THREE } = ENABLE3D

      class MainScene extends Scene3D {
        isRolling = false
        wheel

        async create() {
          this.warpSpeed('-ground')
          this.camera.position.set(20, 20, 40)
          this.camera.lookAt(0, 0, 0)
          this.physics.debug?.enable()

          const distance = 10

          let railLeft = this.add.box({ depth: 80 })
          railLeft.position.x -= distance
          this.physics.add.existing(railLeft, { collisionFlags: 1, mass: 0 })
          railLeft.body.setRestitution(1)

          let railRight = this.add.box({ depth: 80 })
          railRight.position.x += distance
          this.physics.add.existing(railRight, { collisionFlags: 1, mass: 0 })
          railRight.body.setRestitution(1)

          let group = []

          const data = [
            { radiusSegments: 24, radiusTop: 4, radiusBottom: 4, height: 2, z: 0, y: 10 },
            { radiusSegments: 24, radiusTop: 4, radiusBottom: 4, height: 2, z: 0, y: -10 },
            { radiusSegments: 24, radiusTop: 5.5, radiusBottom: 5.5, height: 0.3, z: 0, y: 9 },
            { radiusSegments: 24, radiusTop: 5.5, radiusBottom: 5.5, height: 0.3, z: 0, y: -9 },
            { radiusSegments: 4, radiusTop: 1, radiusBottom: 1, height: 20, z: 0, y: 0 }
          ]

          data.forEach(d => group.push(this.make.cylinder(d)))

          this.wheel = group[0]
          for (let i = 1; i < group.length; i++) {
            this.wheel = this.csg.union(this.wheel, group[i])

            // [bug] you do not have to add this line in version >= 0.20.1
            this.scene.remove(this.wheel)
          }

          this.wheel.material = new THREE.MeshLambertMaterial({ color: 0xcccccc })
          this.wheel.castShadow = this.wheel.receiveShadow = true
          this.wheel.rotateZ(Math.PI / 2)
          this.wheel.position.z -= 20
          this.wheel.position.y -= 4

          this.add.existing(this.wheel)
          this.physics.add.existing(this.wheel, { shape: 'hacd', autoCenter: true, mass: 1000 })

          setTimeout(() => {
            this.isRolling = true
          }, 2000)
        }

        update() {
          if (this.isRolling) this.wheel.body.setAngularVelocityX(1)
        }
      }
      PhysicsLoader('/lib/ammo/moz', () => new Project({ scenes: [MainScene], antialias: true }))
    </script>
  </body>
</html>