Having trouble getting the sample code for Mathf.PerlinNoise to work.

Question

I'm referring to this page, with the specific sample code as follows:

 using UnityEngine;
 using System.Collections;
 
 public class Example : MonoBehaviour {
     public int pixWidth;
     public int pixHeight;
     public float xOrg;
     public float yOrg;
     public float scale = 1.0F;
     private Texture2D noiseTex;
     private Color[] pix;
     void Start() {
         noiseTex = new Texture2D(pixWidth, pixHeight);
         pix = new Color[noiseTex.width * noiseTex.height];
         renderer.material.mainTexture = noiseTex;
     }
     void CalcNoise() {
         float y = 0.0F;
         while (y < noiseTex.height) {
             float x = 0.0F;
             while (x < noiseTex.width) {
                 float xCoord = xOrg + x / noiseTex.width * scale;
                 float yCoord = yOrg + y / noiseTex.height * scale;
                 float sample = Mathf.PerlinNoise(xCoord, yCoord);
                 pix[y * noiseTex.width + x] = new Color(sample, sample, sample);
                 x++;
             }
             y++;
         }
         noiseTex.SetPixels(pix);
         noiseTex.Apply();
     }
     void Update() {
         CalcNoise();
     }
 }

As a pretty new beginner, I don't really know how to apply this, or what to make it a component of. That's part of the problem.

Before I even try anything, however, when I paste this sample code into a new script and save it, the console error immediately spits an error at me:

 Assets/Scripts/Perlin.cs(25,37): error CS0266: Cannot implicitly convert type 'float' to 'int'. An explicit conversion exists (are you missing a cast?)

So, inside the CalcNoise() function, I looked at line 25, where it appears it doesn't like the fact that "pix[y * noiseTex + x]" contains x and y as floats instead of integers.

I'm not sure how to fix it properly, but I tried starting by declaring x and y as integers. This at least made the error disappear from the console. I then tried adding a new plane to the scene and making this script a component of it, but then when I ran it I got a new error:

 Array size must be at least width*height
 UnityEngine.Texture2D:SetPixels(Color[])
 Perlin:CalcNoise() (at Assets/Scripts/Perlin.cs:30)
 Perlin:Update() (at Assets/Scripts/Perlin.cs:34)

...And from here, I'm shamefully lost.

Answer 1

Below is a fixed version of this script. I also established some default values at the top of the file that gives you a result similar to the one in the reference. Create a Quad, attach an material using Unlit/Texture for a the shader, attach this script and hit run:

 using UnityEngine;
 using System.Collections;
 
 public class Bug40 : MonoBehaviour {
     public int pixWidth = 1024;
     public int pixHeight = 1024;
     public float xOrg = 1.2F;
     public float yOrg = 0.34F;
     public float scale = 11.0F;
     private Texture2D noiseTex;
     private Color[] pix;
     void Start() {
         noiseTex = new Texture2D(pixWidth, pixHeight);
         pix = new Color[noiseTex.width * noiseTex.height];
         renderer.material.mainTexture = noiseTex;
     }
     void CalcNoise() {
         float y = 0.0F;
         while (y < noiseTex.height) {
             float x = 0.0F;
             while (x < noiseTex.width) {
                 float xCoord = xOrg + x / noiseTex.width * scale;
                 float yCoord = yOrg + y / noiseTex.height * scale;
                 float sample = Mathf.PerlinNoise(xCoord, yCoord);
                 pix[(int)(y * noiseTex.width + x)] = new Color(sample, sample, sample);
                 x++;
             }
             y++;
         }
         noiseTex.SetPixels(pix);
         noiseTex.Apply();
     }
     void Update() {
         CalcNoise();
     }
 }

it is a bit strange for the example code to call CalcNoise() every frame. I guess that is to allow you to play with xOrg, yOrg, and scale in the inspector and see the result.

Having trouble getting the sample code for Mathf.PerlinNoise to work.

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