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I am stuck in another problem with Noise(I´ve never did this before). Now Terrain is generating and its quite well but its Irrelative to each other. Here is a screenshot

Noise Irrelativity

As you might notice Each column of terrain it isn´t smooth, It makes bruscal Height jumps Example: Instead of doing 2 4 6 7, etc It makes 2 14 16 18 28 46, etc

NOTE: This only happens at high amplitude values but in lower amplitudes its not genration any mountains its almost everything smooth

Here is my Terrain Generation Code:

  public void GenerateChunk(float offsetX, float amplitude)//I am using a value of 73 for amplitude.
{
    for (int y = 200; y < 400; y += 16)
    {   
        for(float x = 0; x < CHUNK_SIZE; x += 1)
        {
                try 
                {
                    float height = (float) PerlinNoise.noise(x+offsetX, 0);
                    height *= amplitude;




                    Block B = new Block(Material.DIRT,(int) (offsetX+(x*16)),(int) height + y, new Image("res/Dirt.png"));
                    Blocks.add(B);
                    B.setVisible(true);
                } 
                catch (SlickException e) 
                {
                    e.printStackTrace();
                }
            }
     }

}

And Here is my Simplex Noise Class:

private static int grad3[][] = { {1,1,0},{-1,1,0},{1,-1,0},{-1,-1,0}, {1,0,1},{-1,0,1},{1,0,-1},{-1,0,-1}, {0,1,1},{0,-1,1},{0,1,-1},{0,-1,-1}};

private static int p[] = { 151,160,137,91,90,15,
                                                131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23,
                                                190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33,
                                                88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166,
                                                77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244,
                                                102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196,
                                                135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123,
                                                5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42,
                                                223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9,
                                                129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228,
                                                251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107,
                                                49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254,
                                                138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180};

// To remove the need for index wrapping, double the permutation table length
private static int perm[] = new int[512];
static {
        for(int i = 0; i < 512; i++)
                perm[i] = p[i & 255];
}

// This method is a *lot* faster than using (int)Math.floor(x)
private static int fastfloor(double x) {
        return x > 0 ? (int)x : (int)x - 1;
}

private static double dot(int g[], double x, double y) {
        return g[0] * x + g[1] * y;
}

// 2D simplex noise
public static double noise(double xin, double yin) {
        double n0, n1, n2;

        final double F2 = 0.5 * (Math.sqrt(3.0) - 1.0);
        double s = (xin + yin) * F2;
        int i = fastfloor(xin + s);
        int j = fastfloor(yin + s);

        final double G2 = (3.0 - Math.sqrt(3.0)) / 6.0;
        double t = (i + j) * G2;
        double X0 = i - t;
        double Y0 = j - t;
        double x0 = xin - X0;
        double y0 = yin - Y0;

        int i1, j1;
        if (x0 > y0) {
                i1=1;
                j1=0;
        } else {
                i1 = 0;
                j1 = 1;
        }

        double x1 = x0 - i1 + G2;
        double y1 = y0 - j1 + G2;
        double x2 = x0 - 1.0 + 2.0 * G2;
        double y2 = y0 - 1.0 + 2.0 * G2;

        int ii = i & 255;
        int jj = j & 255;
        int gi0 = perm[ii + perm[jj]] % 12;
        int gi1 = perm[ii + i1 + perm[jj + j1]] % 12;
        int gi2 = perm[ii + 1 + perm[jj + 1]] % 12;

        double t0 = 0.5 - x0 * x0 - y0 * y0;
        if(t0 < 0)
                n0 = 0.0;
        else {
                t0 *= t0;
                n0 = t0 * t0 * dot(grad3[gi0], x0, y0);
        }

        double t1 = 0.5 - x1 * x1 - y1 * y1;
        if(t1 < 0)
                n1 = 0.0;
        else {
                t1 *= t1;
                n1 = t1 * t1 * dot(grad3[gi1], x1, y1);
        }

        double t2 = 0.5 - x2 * x2 - y2 * y2;
        if(t2 < 0)
                n2 = 0.0;
        else {
                t2 *= t2;
                n2 = t2 * t2 * dot(grad3[gi2], x2, y2);
        }

        return 70.0 * (n0 + n1 + n2);
}


public static void genGrad(long seed) {
    Random rnd = new Random(seed);
    for(int i = 0; i < 255; i++)
      p[i] = i;
    for(int i = 0; i < 255; i++) {
      int j = rnd.nextInt(255);
      int nSwap = p[i];
      p[i]  = p[j];
      p[j]  = nSwap;
    }

for(int i = 0; i < 512; i++)
        perm[i] = p[i & 255];
}
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1 Answer 1

1
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Probably the frequency of the noise is too high. You can control the frequency by scaling the input to the noise function:

float height = (float) PerlinNoise.noise(frequency * (x+offsetX), 0);

You can then tweak the value as desired. Lower frequencies will produce smoother terrain, with a larger horizontal scale for the bumps. You can then adjust the amplitude to set the desired vertical scale for the bumps.

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  • \$\begingroup\$ There is no big change.Now its generating a bit smoother terrain but still isnt so smooth.Mountains are just a small elevation. I tried tweaking the values but there no big change \$\endgroup\$
    – Zaphyk
    Apr 3, 2014 at 1:15
  • \$\begingroup\$ @Zaphyk What did you set the frequency to? If your x-values are in pixels, you might have to set it to something quite low, like 0.01. Also, is your noise function known good (i.e. you got it from a known working source), or could there be bugs in it as well? \$\endgroup\$ Apr 3, 2014 at 6:13
  • \$\begingroup\$ Nice, it did it. I love the results now they are a lot smoother Thank you a lot. :D \$\endgroup\$
    – Zaphyk
    Apr 5, 2014 at 3:14

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