Hello,

So from what I understand, a noise function is a seeded random function. That is why running

for (int i = 0; i <= 100; i ++) {
 float y = noise(1.0);
 line (0, y * 100, 100, 100);
}

will produce the same y value each time the for loop runs, thereby drawing the same line repeatedly over itself, whereas

for (int i = 0; i <= 100; i ++) {  
 float y = random(1.0);          
 line (0, y * 100, 100, 100);    
}

will have a different y value each time the for loop runs, and will result in many different lines being drawn on top of each other.

I understand that adding noiseSeed() to the first program will ensure that the value of y is the same every time the program is run. What I don't understand then is what does the value of the noise() function's parameter specify?

Is it the value between 0.0 and 1.0 that corresponds to the parameter's location within the sequence of numbers generated?

Does running the function without noiseSeed() cause a sequence of numbers to be generated from an arbitrary number selected by the noise() function each time the program is run?

Ah cool thank you that definitely helped. I've been trying to visualize the noise() function and here's how I understand it thus far:

The noise() function is a seeded random function that returns values between 0.0 and 1.0. If this function were graphed, then the parameter in noise() would be the x position on the graph, and the value returned would be the corresponding y position. Increasing the value of x is like moving down the x axis and therefore the value returned becomes the y value at the new x position.

Am I on the right track or am I going in the wrong direction? I'm also having trouble understanding how a two-parameter noise function works. I can't figure out how the first parameter and the second parameter interact to produce a single value.

Hello,

No not at all, thank you very much; I appreciate the detailed explanations. Visualizing the noise as a grid of values between 0.0 and 1.0 really helped break through the impasse I was at. One thing I still don't understand, although it's more just curiosity, is why, in a program like this:

size(500, 500);
float xnoise = 0.0;
float ynoise = 0.0;
float inc = 0.075;

for (int y = 0; y < height; y++) {
 for (int x = 0; x < width; x ++) {
   float gray = noise(xnoise, ynoise) * 255;
   stroke(gray);
   point(x, y);
   xnoise += inc;
 }
 xnoise = 0;
 ynoise = ynoise + inc;
}

does the noise function() produce a repetitive pattern in the x direction?

Thank you!