Ring.qml Example File

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  import Qt3D.Render 2.0

  // TODO: Once support for meshes from arrays is implemented, replace ring.obj with that
  Mesh {
      property real innerRadius
      property real outerRadius
      /*
      property real ringSegments

      property var vertices: []
      property var faces: []
      property var faceVertexUvs: []
      */

      source: "qrc:/meshes/ring.obj"

      // Converted from the _RingGeometry() method in the threex.planets.js extension.
      /*
      function makeRing() {
          innerRadius = innerRadius || 0
          outerRadius = outerRadius || 50
          var thetaSegments = ringSegments || 8
          console.log(innerRadius + "," + outerRadius + "," + thetaSegments)

          var normal = Qt.vector3d(0, 0, 1)

          for (var i = 0; i < thetaSegments; i++) {
              var angleLo = (i / thetaSegments) * Math.PI * 2
              var angleHi = ((i + 1) / thetaSegments) * Math.PI * 2

              var vertex1 = Qt.vector3d(innerRadius * Math.cos(angleLo),
                                        innerRadius * Math.sin(angleLo),
                                        0)
              var vertex2 = Qt.vector3d(outerRadius * Math.cos(angleLo),
                                        outerRadius * Math.sin(angleLo),
                                        0)
              var vertex3 = Qt.vector3d(innerRadius * Math.cos(angleHi),
                                        innerRadius * Math.sin(angleHi),
                                        0)
              var vertex4 = Qt.vector3d(outerRadius * Math.cos(angleHi),
                                        outerRadius * Math.sin(angleHi),
                                        0)

              vertices.push(vertex1)
              vertices.push(vertex2)
              vertices.push(vertex3)
              vertices.push(vertex4)

              var vertexIdx = i * 4

              // Create the first triangle
              var face = Qt.vector4d(vertexIdx + 0, vertexIdx + 1, vertexIdx + 2, normal)
              var uvs = []

              var uv = Qt.vector2d(0, 0)
              uvs.push(uv)
              uv = Qt.vector2d(1, 0)
              uvs.push(uv)
              uv = Qt.vector2d(0, 1)
              uvs.push(uv)

              faces.push(face)
              //faceVertexUvs[0].push(uvs)
              faceVertexUvs.push(uvs)

              // Create the second triangle
              face = Qt.vector4d(vertexIdx + 2, vertexIdx + 1, vertexIdx + 3, normal)
              uvs = []

              uv = Qt.vector2d(0, 1)
              uvs.push(uv)
              uv = Qt.vector2d(1, 0)
              uvs.push(uv)
              uv = Qt.vector2d(1, 1)
              uvs.push(uv)

              faces.push(face)
              //faceVertexUvs[0].push(uvs)
              faceVertexUvs.push(uvs)
          }

          computeFaceNormals()
      }

      // Converted from the computeFaceNormals() method in the three.js extension.
      function computeFaceNormals() {
          var cb = Qt.vector3d(0, 0, 0)
          var ab = Qt.vector3d(0, 0, 0)

          for (var f = 0, fl = faces.length; f < fl; f ++) {
              var face = faces[f]

              var vA = vertices[face.x]
              var vB = vertices[face.y]
              var vC = vertices[face.z]

              cb = vC.minus(vB)
              ab = vA.minus(vB)
              cb = cb.crossProduct(ab)

              cb = cb.normalized()

              face.w = cb
          }
      }
      */
  }