calcSurfacePoint function

dynamic calcSurfacePoint(dynamic p, dynamic q, dynamic U, dynamic V, dynamic P, dynamic u, dynamic v, dynamic target,)

Implementation

calcSurfacePoint(p, q, U, V, P, u, v, target) {
  var uspan = findSpan(p, u, U);
  var vspan = findSpan(q, v, V);
  var nu = calcBasisFunctions(uspan, u, p, U);
  var nv = calcBasisFunctions(vspan, v, q, V);
  var temp = [];

  for (var l = 0; l <= q; ++l) {
    temp[l] = Vector4(0, 0, 0, 0);
    for (var k = 0; k <= p; ++k) {
      var point = P[uspan - p + k][vspan - q + l].clone();
      var w = point.w;
      point.x *= w;
      point.y *= w;
      point.z *= w;
      temp[l].add(point.multiplyScalar(nu[k]));
    }
  }

  Vector4 sw = Vector4(0, 0, 0, 0);
  for (var l = 0; l <= q; ++l) {
    sw.add(temp[l].multiplyScalar(nv[l]));
  }

  sw.divideScalar(sw.w);
  target.set(sw.x, sw.y, sw.z);
}