I am trying to apply perlin noise to a line renderer in unity 2d here is my code:

public class Ground : MonoBehaviour
{
    private static bool seedGenerated;
    public static float Seed;
    public LineRenderer LineR;
    public EdgeCollider2D col;
    private Vector2[] points;
    public int lengthOfLineRenderer;
    public float scale = 20f;
    public float OffsetX = 0;
    public float OffsetY = 0f;
    // Start is called before the first frame update
    void Start()
    {
        if(!seedGenerated)
        {
            Seed = Random.Range(0f,9999f);
            seedGenerated = true;
        }
        OffsetX = Seed   transform.position.x;
        points = new Vector2[lengthOfLineRenderer * 10   1];
        LineR.positionCount = lengthOfLineRenderer * 10   1;

        for (float i = 0f; i < lengthOfLineRenderer; i  = 0.1f)
        {
            LineR.SetPosition((int)Mathf.Round(i * 10), new Vector3(i,CalculateHeight(i),0.0f));
            //points[(int)Mathf.Round(i*10)] = new Vector2(i,CalculateHeight(i));
        }
        LineR.SetPosition(100,new Vector3(10f,CalculateHeight(10f),0));
        points[100] = new Vector2(10f,CalculateHeight(101));
        col.points = points;
    }

    // Update is called once per frame
    void Update()
    {

    }
    float CalculateHeight(float x)
    {
        float width = lengthOfLineRenderer * 10;
        float xCoord = x / width * scale   OffsetX;
        return Mathf.PerlinNoise(xCoord,OffsetY);
    }
}

the positions are applied correctly and the variable lengthOfLineRenderer is equal to 10 because I want the scale of the line to be 10 everything works fine but when I spawn another line with a 10 offset different in OffsetX they dont seem to align correctly most of the time, is the problem in my code or in the perlin noise method?

CodePudding user response：

Let's just do some simple math. According to your description we have:

lengthOfLineRenderer = 10
scale = 10
width = lengthOfLineRenderer * 10
      = 100

The last point of the first line is:

xCoord = 10f / width * scale   OffsetX
       = 10f / 100 * 10   OffsetX
       = 1   OffsetX

The first point of the second line (with a 10 offset different in OffsetX) is:

xCoord = 0f / width * scale   OffsetX   10
       = OffsetX   10

Apparently 1 OffsetX != OffsetX 10, so to make them equal you need scale = 100.

CodePudding user response：

here is the new code I fixed some stuff in:

    private static bool seedGenerated;
    public static float Seed;
    public LineRenderer LineR;
    public EdgeCollider2D col;
    private Vector2[] points;
    public int lengthOfLineRenderer;
    public float scale;
    public float OffsetX = 0;
    public float OffsetY = 0f;
    public float frequency;
    // Start is called before the first frame update
    void Start()
    {
        if(!seedGenerated)
        {
            Seed = Random.Range(0,9999);
            seedGenerated = true;
        }
        OffsetX = Seed   transform.position.x;
        points = new Vector2[lengthOfLineRenderer * 10 1 ];
        LineR.positionCount = lengthOfLineRenderer * 10 1 ;

        for (float i = 0f; i < lengthOfLineRenderer 0.1f; i  = 0.1f)
        {
            LineR.SetPosition((int)Mathf.Round(i * 10), new Vector3(i,CalculateHeight(i) * frequency,0.0f));
            points[(int)Mathf.Round(i*10)] = new Vector2(i,CalculateHeight(i) * frequency);
        }
        col.points = points;
    }

    // Update is called once per frame
    void Update()
    {

    }
    float CalculateHeight(float x)
    {
        float width = lengthOfLineRenderer * 10;
        float xCoord = x / width * scale   OffsetX;
        return Mathf.PerlinNoise(xCoord,OffsetY);
    }