Алгоритм-квадрат алгоритм случайный и шумный

Я реализовал грубую интерпретацию Алмазный квадратный алгоритм в C ++, чтобы создать некоторую полуреалистичную фрактальную местность, но вывод просто кажется случайным значением y в каждой точке, а не гладкими скалистыми формами. Я изменил параметры, но чувствую, что внешний взгляд на код может помочь мне понять проблему. Вот примеры вывода:

Я получил это:

И должно выглядеть так:

Код:

//Diamond-square algorithm
HeightMap::HeightMap(float maxY) {
//type = GL_POINTS;
//type = GL_LINES;
numVertices = RAW_WIDTH*RAW_HEIGHT; //256^2 squares => 257^2 vertices
numIndices = (RAW_WIDTH - 1)*(RAW_HEIGHT - 1) * 6; //each square is 2 triangles (6 indices)
vertices = new Vector3[numVertices];
textureCoords = new Vector2[numVertices];
indices = new GLuint[numIndices];
colours = new Vector4[numVertices];

int cornerA, cornerB, cornerC, cornerD; //Identify corners
cornerA = 0;
cornerB = RAW_WIDTH - 1;
cornerC = RAW_WIDTH*RAW_HEIGHT - RAW_WIDTH;
cornerD = RAW_WIDTH*RAW_HEIGHT - 1;

//Create vertices
for (int x = 0; x < RAW_WIDTH; ++x) {
for (int z = 0; z < RAW_HEIGHT; ++z) {
int offset = (x * RAW_WIDTH) + z;
float y = 0; //Start with vertices set flat
if (offset == cornerA ||
offset == cornerB ||
offset == cornerC ||
offset == cornerD) {
vertices[offset] = Vector3(x * HEIGHTMAP_X, maxY/2, z * HEIGHTMAP_Z); //Initialise corners to mid height
std::cout << "Corners: " << offset << std::endl;
}

if (vertices[offset] == Vector3(0, 0, 0)) {
vertices[offset] = Vector3(x * HEIGHTMAP_X, y * HEIGHTMAP_Y, z * HEIGHTMAP_Z);
}
//  textureCoords[offset] = Vector2(x * HEIGHTMAP_TEX_X, z * HEIGHTMAP_TEX_Z);
}
}

Vector3 tl, tr, bl, br;
tl = vertices[cornerA];
tr = vertices[cornerB];
bl = vertices[cornerC];
br = vertices[cornerD];

float roughness = 1.0f;

Square square = Square(tl, tr, bl, br);
diamondSquare(vertices, numVertices, square, roughness);

//Colour
for (int x = 0; x < RAW_WIDTH; ++x) {
for (int z = 0; z < RAW_HEIGHT; ++z) {
int offset = (x*RAW_WIDTH) + z;
float shade;
if (vertices[offset].y > 0) {
shade = 1 - 1.0f / (vertices[offset].y / maxY * 2);
}
else {
shade = 0.1f;
}
colours[offset] = Vector4(shade, shade, shade, 1.0f);
//Colour any vertex that hasn't been passed over red
if (vertices[offset].y == maxY / 2 + 100) {
colours[offset] = Vector4(1, 0, 0, 1);
}
}
}

//Create indices
numIndices = 0;
for (int x = 0; x < RAW_WIDTH - 1; ++x) {
for (int z = 0; z < RAW_HEIGHT - 1; ++z) {
int a = (x*(RAW_WIDTH)) + z;
int b = ((x + 1)*(RAW_WIDTH)) + z;
int c = ((x + 1)*(RAW_WIDTH)) + (z + 1);
int d = (x*(RAW_WIDTH)) + (z + 1);

indices[numIndices++] = c;
indices[numIndices++] = b;
indices[numIndices++] = a;
indices[numIndices++] = a;
indices[numIndices++] = d;
indices[numIndices++] = c;

}
}
BufferData();

}

void HeightMap::squareStep(Vector3 vertices[], int len, Vector3 tl, Vector3 tr, Vector3 bl, Vector3 br, float mid, float roughness) {
for (int i = 0; i < len; i++) {
Vector3 top = (tl + tr) / 2;
Vector3 bot = (bl + br) / 2;
Vector3 left = (tl + bl) / 2;
Vector3 right = (tr + br) / 2;
top.y = 0;
bot.y = 0;
left.y = 0;
right.y = 0;
if (vertices[i] == top ||
vertices[i] == bot ||
vertices[i] == left ||
vertices[i] == right) {
float y = rand() % (int)(mid/5);
y *= roughness;
vertices[i] = Vector3(vertices[i].x, mid + y, vertices[i].z); //Set Diamond centre points to mid height + rand
std::cout << "Square: " << vertices[i];
}
}

}

float HeightMap::diamondStep(Vector3 vertices[], int len, Vector3 tl, Vector3 tr, Vector3 bl, Vector3 br, float roughness) {
float avg;
float y;
for (int i = 0; i < len; i++) {
Vector3 corners = (tl + tr + bl + br) / 4;
avg = corners.y;
y = rand() % (int)(avg/5);
y *= roughness;
corners.y = 0;
if (vertices[i] == corners) {
vertices[i] = Vector3(vertices[i].x, avg + y, vertices[i].z);         //Set Square centre point to avg height of corners + rand
std::cout << "Diamond: " << vertices[i];
}
}
return avg + y;

}

void HeightMap::diamondSquare(Vector3 vertices[], int numVertices, Square s, float roughness) {
Vector3 tl = s.tl;
Vector3 tr = s.tr;
Vector3 bl = s.bl;
Vector3 br = s.br;
float mid = diamondStep(vertices, numVertices, tl, tr, bl, br, roughness);
squareStep(vertices, numVertices, tl, tr, bl, br, mid, roughness);
roughness *= 0.75f;
if (s.width > 2 * HEIGHTMAP_X) {
std::vector<Square> squares = s.split();
for (int i = 0; i < 4; i++) {
diamondSquare(vertices, numVertices, squares[i], roughness);
}
}

}