Undesirable lines in "random" star generation - math

Question

I'm creating a star field in a three.js scene. The code to generate the random positions of the stars is below. When the stars are rendered and the camera is pulled back enough from the center of the scene, there are a couple of visible "empty" tracks in the placement of the stars.
I'm assuming it has to do with the math in the _addStars method. Can anyone help me to tighten up the placement of the stars throughout the entire canvas?
Note: The canvas I have to work with is somewhere around an 8:1 ratio height:width. So just repositioning the camera is not an option.
UPDATE: I've added a fiddle to demonstrate the issue: https://jsfiddle.net/scottwatkins/5zjoLLpx/5/
/** Method to generate the stars and place them in the particle system */
_addStars: function () {
var starColors = [];
var starGeometry = new THREE.Geometry();
starGeometry.colors = starColors;
for (var i = 0; i < this.totalStars; i++) {
var x = 120 - Math.random() * 1040;
var y = 480 - Math.random() * 1040;
var z = 0 - Math.random() * 1040;
starGeometry.vertices.push( new THREE.Vector3( x, y, z ) );
var starColor = new THREE.Color(0xffffff);
starColor.setRGB(
.8 + Math.random() * .2,
.8 + Math.random() * .2,
.8 + Math.random() * .2);
starColors.push(starColor)
}
var starMaterial = new THREE.PointsMaterial( {
size: 2.0,
map: this.starTexture,
depthTest: false,
depthWrite: false,
blending: THREE.AdditiveBlending,
transparent : true,
vertexColors: true
} );
this.particleSystem = new THREE.Points( starGeometry, starMaterial );
this.scene.add(this.particleSystem);
}

Answer 1

It appears to be caused by Math.random() seems to work with THREE.Math.random16()
var x = 120 - THREE.Math.random16() * 1040;
var y = 480 - THREE.Math.random16() * 1040;
var z = 0 - THREE.Math.random16() * 1040;
Here's what it says in the docs for THREE.Math.random16():
Random float from 0 to 1 with 16 bits of randomness.
Standard Math.random() creates repetitive patterns when applied over larger space.
Updated fiddle: here