hemisphere-sample/dist/index.js

Uniform and cosinus hemisphere sampling using hammersley point set

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.hemisphereSampleUniform = hemisphereSampleUniform;
exports.hemisphereSampleCos = hemisphereSampleCos;

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { "default": obj }; }

var _hammersley = require("hammersley");

var _hammersley2 = _interopRequireDefault(_hammersley);

var PI = Math.PI;

function hemisphereSampleUniform(i, N) {
  var hPoint = (0, _hammersley2["default"])(i, N);
  var u = hPoint[0];
  var v = hPoint[1];
  var phi = v * 2.0 * PI;
  var cosTheta = 1.0 - u;
  var sinTheta = Math.sqrt(1.0 - cosTheta * cosTheta);
  return [Math.cos(phi) * sinTheta, Math.sin(phi) * sinTheta, cosTheta];
}

function hemisphereSampleCos(i, N) {
  var hPoint = (0, _hammersley2["default"])(i, N);
  var u = hPoint[0];
  var v = hPoint[1];
  var phi = v * 2.0 * PI;
  var cosTheta = Math.sqrt(1.0 - u);
  var sinTheta = Math.sqrt(1.0 - cosTheta * cosTheta);
  return [Math.cos(phi) * sinTheta, Math.sin(phi) * sinTheta, cosTheta];
}