p5.js noise() Function

The noise() function is used to return a number generated by Perlin noise at the given coordinates. This value is semi-random, which means that the value would be fixed for a coordinate for the lifespan of the program.

The Perlin noise value is different from the value returned by the random() function as this noise has a more natural and harmonic succession compared to the standard one.

Syntax:

noise(x, [y], [z])

Parameter: This function accept three parameters as mentioned above and described below:

• x: This is a number which represents the x-coordinate in the noise space.
• y: This is a number which represents the y-coordinate in the noise space. It is an optional parameter.
• z: This is a number which represents the z-coordinate in the noise space. It is an optional parameter.

Return Value: It returns the Perlin noise value between 0 and 1.

Below examples illustrates the noise() function in p5.js:

Example 1: Plotting the noise values of the y-coordinate of the moving point.

• Program:

  let x_coordinate = 100.0;
  let plot_x = 10.0;
  
  function setup() {
      createCanvas(400, 200);
  }
  
  function draw() {
  
      // Get noise with x coordinate
      x_noise = noise(x_coordinate) * 100;
  
      // Plot the point with random noise
      strokeWeight(10);
      point(plot_x, x_noise);
  
      // Increment the x coordinate
      x_coordinate++;
  
      // Increase the x coordinate
      // for plotting
      plot_x++;
  }
• Output:
  

  

Example 2: This example demonstrates the semi-random property of a function.

• Program:

  let x_coordinate = 0.0;
  let plot_y = 0.0;
  
  function setup() {
      createCanvas(400, 200);
  }
  
  function draw() {
  
      if (x_coordinate < 5) {
  
          // Get noise with x coordinate
          x_noise = noise(x_coordinate);
  
          // Output the noise along with
          // its corresponding coordinate
          coord_text = "Noise for x coordinate "
              + x_coordinate + " is " + x_noise;
  
          text(coord_text, 10, plot_y);
  
          // Increment the x coordinate
          x_coordinate++;
  
          // Increase the y coordinate
          // for plotting
          plot_y = plot_y + 15;
      }
      else
          x_coordinate = 0;
  }
• Output:
  

  

Example 3: This example uses two parameters for defining a point in the noise space.

• Program:

  let x_coordinate = 0.0;
  let y_coordinate = 0.0;
  let plot_y = 0.0;
  
  function setup() {
      createCanvas(400, 200);
  }
  
  function draw() {
  
      if (x_coordinate < 10) {
  
          // Get noise with x and y coordinates
          xy_noise = noise(x_coordinate, y_coordinate);
  
          // Output the noise along with
          // its corresponding coordinate
          coord_text = "Noise for coordinates: "
              + x_coordinate + ", " + y_coordinate
              + " is " + xy_noise;
          text(coord_text, 10, plot_y);
  
          // Increment the x and y
          // coordinates
          x_coordinate++;
          y_coordinate++;
  
          // Increase the y coordinate
          // for plotting
          plot_y = plot_y + 15;
      }
  }
• Output:
  

  

Online editor: https://editor.p5js.org/
Environment Setup: https://www.geeksforgeeks.org/p5-js-soundfile-object-installation-and-methods/amp/

Reference: https://p5js.org/reference/#/p5/noise