Hello.
Today I've implemented a perlin noise algorithm with extra methods like pertubation and eroding to create a terrain. 
I found the code for it here: Click me
After the "addPerlinNoise()" method, you can see 3 reference pictures on that page (in the middle), build with the frequencies 1.0f, 4.0f and 1.0f + 8.0f (without perturb or sth like that, just plain noise).
If I use a frequency of 4.0f, this is my output (plain noise): https://imgur.com/7OElD3n
And when I use 64.0f as my frequency, I get this: https://imgur.com/dqA04N6
Can you help me to achieve something like the reference pictures with the reference frequencies (1.0f, 4.0f, 1.0f + 8.0f)?
I only understand a little behind the maths of it, so I can't really do something to fix it. 
The code on the linked site is in C#, mine is in C++.
The only things, which are different between my code and the code on the site is the following part:
void PerlinGenerator::initGradients()
{
//Type of random number distribution
std::uniform_real_distribution<float> dist(0.0f, 1.0f); //(min, max)
//Mersenne Twister: Good quality random number generator
std::mt19937 rng;
//Initialize with non-deterministic seeds
rng.seed(std::random_device{}());
for (int i = 0; i < gradientTableSize; i++)
{
float z = 1.0f - 2.0f * dist(rng);
float r = (float)sqrt(1.0f - z * z);
float theta = 2 * (float)M_PI * dist(rng);
gradients[i * 3] = r * cos(theta);
gradients[i * 3 + 1] = r * sin(theta);
gradients[i * 3 + 2] = z;
}
}
Can it be the random double, which is used for the computing?
For the rendering I determine the vertex coordinates for a VBO like this and render it with glDrawElements(...) :
void Terrain::createVBO()
{
// Create vertex data
float *vertices = new float[3 * heightMap->size * heightMap->size];
float blockSize = 16.0f;
int vertex = 0;
for (int y = 0; y < heightMap->size; y++) {
for (int x = 0; x < heightMap->size; x++) {
vertices[vertex++] = x * blockSize;
vertices[vertex++] = y * blockSize;
vertices[vertex++] = heightMap->heights[y][x] * blockSize;
}
}
// Create index data
[...]
// Create VAO
[...]
// Create VBO
[...]
// Create EBO
[...]
// Handle vertex attributes in shader prog
[...]
}
Hopefully you can help me, thanks,
NightDreamer
