Randomized Terrain 

LINK TO WORKING CODE

var cols, rows;

var scl = 20;

var w = 2000;

var h = 1600;

var flying = 0;

var terrain;

function setup() {

  createCanvas(600, 600, WEBGL);

  cols = w / scl;

  rows = h / scl;

  terrain = create2DArray(cols, rows);

}

function draw() {

  flying -= 12;

  var yoff = flying;

  for (var y = 0; y < rows; y++) {

    var xoff = 0;

    for (var x = 0; x < cols; x++) {

      terrain[x][y] = map(noise(xoff, yoff), 0, 1, -100, 100);

      xoff += 0.2;

    }

    yoff += 0.2;

  }

  background(0);

  stroke(255);

  noFill();

  // translate(width / 2, height / 2);

  rotateX(PI / 3);

  translate(-width, -height / 2 + 50);

  for (var y = 0; y < rows - 1; y++) {

    beginShape(TRIANGLE_STRIP);

    for (var x = 0; x < cols; x++) {

      vertex(x * scl, y * scl, terrain[x][y]);

      vertex(x * scl, (y + 1) * scl, terrain[x][y + 1]);

      // rect(x * scl, y * scl, scl, scl);

    }

    endShape();

  }

}

function create2DArray(numArrays, numSubArrays) {

  var arr = new Array(numArrays);

  for (var i = 0; i < numArrays; i++) {

    arr[i] = new Array(numSubArrays);

  }

  return arr;

}