Just Completed My Perlin Noise (?) Function!

[anon_71329978]

Hey guys!

I just spend ~7 hours researching and coding a perlin noise function in Unity (It’s 5am here, yay!).

I am still, however, a relative newbie at this kind of stuff. In fact, I’m not even entirely sure it is perlin noise.

With that said, I would greatly appreciate it if one of you fellow programmers took the time to analyze/criticize my code. Let me know: Is it “technically” perlin noise? Are there any major optimizations I could make to it? I know I didn’t implement a frequency/amplitude variable. Does anyone know how I should implement that?

Lastly, I plan on using this to generate random terrain levels for my game. I need to make the “edges” of the texture black to represent water, like an ocean with an island-ish region in it. Does anyone have any tips regarding the implementation of this i.e., where to start :P?

Thanks guys!

private var map : Texture2D;
var octaves : int = 1;

function CreateTexture() {
map = Texture2D(64,64,TextureFormat.ARGB32,false);
map.anisoLevel = 0;
map.filterMode = FilterMode.Point;
}

function Noise(x : int,y : int) {
for(var i = octaves; i <= octaves; i++) {
var randomVal : float = Random.value;
return map.GetPixel(x,y) + Color(randomVal,randomVal,randomVal,1);
}
}

function AvrgColor(x : int, y : int) { //take average of the color values of all surrounding pixels of(x,y).
sides = (map.GetPixel(x-1,y) + map.GetPixel(x+1,y) + map.GetPixel(x,y-1) + map.GetPixel(x,y+1)) / 4;
corners = (map.GetPixel(x-1,y-1) + map.GetPixel(x+1,y+1) + map.GetPixel(x+1,y-1) + map.GetPixel(x-1,y+1)) / 4;
return (sides + corners) /2;
}

function PerlinNoise() {
for(var x = 1; x <= map.width; x++) {
for(var y = 1; y <= map.height; y++) {
map.SetPixel(x,y,Color.black);
map.SetPixel(x,y,Noise(x,y));
}
}
for(var x2 = 1; x2 <= map.width; x2++) { //iterate a second time, averaging values
for(var y2 = 1; y2 <= map.height; y2++) {
map.SetPixel(x2,y2,AvrgColor(x2,y2));
}
}
map.Apply();
}

function Start() {
CreateTexture();
PerlinNoise();
}

[anon_38331066]

@anon_71329978

Is it “technically” perlin noise?

short answer: NO

[UnLogick]

I think its a far stretch to call this Perlin noise, in theory everything can be called 1 octave Perlin noise. What you got there is blended white noise. The concept of perlin is to combine noise from several octaves(layers) so to use an octave count of 1 defeats the concept of Perlin. Also Perlin noise revolves around the concept that if you ever re-calculated the Perlin noise you would get the same output. Your code is truly random, and such you wont get the same result multiple times.

May I suggest you read this excellent illustrated text on Perlin Noise. Notice how each octave have a different amplitude(height) and frequency(resolution). Its not the raw Perlin implementation, but its much easier to grasp, and it does show what makes Perlin Noise special.
http://freespace.virgin.net/hugo.elias/models/m_perlin.htm

Cheers,
Unlogick

[anon_38331066]

long answer:

here is the original paper from Mr. Perlin
http://mrl.nyu.edu/~perlin/noise/

or a port version for unity
http://forum.unity3d.com/threads/33725-Perlin-noise-procedural-shader

[ivkoni]

Also, the procedural examples have a Perlin noise function.
I also did some noise shader before (not nearly as good as apple_motion’s ). I don’t remember if it was Perlin though.

[anon_38331066]

@ivkoni

I don’t remember if it was Perlin though.

me too, I did not know that was called perlin until I finished the demo

that’s why I love to post my demo or test in here or youtube, because each time I posted something, I found someone did better than me, and that make me understand more more

[anon_71329978]

Hey guys, thanks for all the feedback. I love our community here!

I will definity look into the links you guys posted and improve my concept.