So remember, indices always start at 0, so by accessing the first element with: const x = planeGeoArray[i];, we are getting the x value within the array. These arrays are laid out where the first element is x, the second is y, and the third is z. So if we were to get the next element within the array, we'd add 1 onto i which would give us the second element within the array. Finally, by adding 2 onto i, we'd effectively get the third element in the array.

The array would looks something like this:

const planeGeoArray = [x, y, z]

So you can see how using i for your index can give you x, y, and z.

With this line:

planeGeoArray[i + 2] = z + Math.random();  }

we're selecting the z location for that one specific point, then altering it by its current location by a random value we generate. z is different for each point we loop through, so for each iteration, we call Math.random() and generate a new value to add on.

Hope that makes sense, can explain more if needed.

Thanks.

so:

for (let i = 0; i < planeGeoArray.length; i+=3) {

console.log(i)

}

so this gives me: 0, 3, 6, 9, and etc.

to get to z points in the array we need to add 2 and will give us as follows: 2, 5, 8, 11, and etc. These points hold the value of z.

Now we want to give new values to the z vertices as right now all points in the array for z = 0. We change z vertices as follows:

Getting the point in the array: 2, 5 and etc. which are z vertex
const z = planeGeoArray[i + 2]; // 2, 5, 8, and etc.

Taking our vertex of z we desire and then add a new z value
with Math.random. Ex: 5 = 5 + Math.random();
planeGeoArray[i + 2] = z + Math.random();

Am I on the right track? lol

Please let me know Chris.

Yes, exactly, definitely on the right track.

planeGeoArray[i + 2] = z + Math.random();

This statement right here says: take the current z-position, the add on a randomly generated number 0-1 onto it. You could also randomize the z-position in the opposite direction by using Math.random() to obtain a negative value along with a positive one like so:

planeGeoArray[i + 2] = z + (Math.random() - 0.5);

This'll give you any number -0.5 to 0.5, thus allowing z to be affected in both directions.

thanks.

I did it this way, does this seem okay?

for (let index = 2; index < array.length; index+=3) {

  // Get z values
  const z = array[index];

  // place new z values into z vertices
  array[index] = z + Math.random();

}

Also, const z = array[index] this gives me '0' does it also give me the position in the array or just the value?

Hi atrimn, believe we may have talked over email, but go ahead and give the page a refresh and try again. You should have full course access with all associated Git repos as soon as you've purchased.

Just shoot me an email at chris@chriscourses.com if there are ever any issues 🙌

Hi Chris, I am also missing access to the repo. I have purchased the bundle under user flight505

Thanks

Hi flight505, can you try clicking on the purple "Video Source Code" button beneath the video when logged in? You should be redirected to the repo from there, but let me know if it's still giving you any issues.