/// <summary>
/// Creates a 20 sided polygon
/// </summary>
/// <returns>Mesh that is the Icosahedron</returns>
public static Mesh CreateIcosahedron()
{
Icosahedron lShape = new Icosahedron();
Mesh lMesh = new Mesh();
lMesh.hideFlags = HideFlags.HideAndDontSave;
lMesh.vertices = lShape.Vertices;
lMesh.triangles = lShape.Triangles;
lMesh.RecalculateNormals();
return lMesh;
}
static void get_triangulation(int num, Icosahedron ico)
{
Dictionary<Vector3, int> vertDict = new Dictionary<Vector3, int>(); // dict lookup to speed up vertex indexing
float[,] subdivision = getSubMatrix(num + 2); // vertex subdivision matrix calculation
Vector3 p1, p2, p3;
int index = 0;
int vertIndex;
int len = subdivision.GetLength(0);
int triNum = (num + 1) * (num + 1) * 20; // number of triangle faces
vertices = new Vector3[triNum / 2 + 2]; // allocate verticies, triangles, etc...
triangleIndices = new int[triNum * 3];
triangles = new int[triNum, 3];
Vector3[] tempVerts = new Vector3[len]; // temporary structures for subdividing each Icosahedron face
int[] tempIndices = new int[len];
int[,] triIndices = triangulate(num); // precalculate generic subdivided triangle indices
int triLength = triIndices.GetLength(0);
for (int i = 0; i < 20; i++) // calculate subdivided vertices and triangles for each face
{
p1 = ico.Vertices[ico.Triangles[i * 3]]; // get 3 original vertex locations for each face
p2 = ico.Vertices[ico.Triangles[i * 3 + 1]];
p3 = ico.Vertices[ico.Triangles[i * 3 + 2]];
for (int j = 0; j < len; j++) // calculate new subdivided vertex locations
{
tempVerts[j].x = subdivision[j, 0] * p1.x + subdivision[j, 1] * p2.x + subdivision[j, 2] * p3.x;
tempVerts[j].y = subdivision[j, 0] * p1.y + subdivision[j, 1] * p2.y + subdivision[j, 2] * p3.y;
tempVerts[j].z = subdivision[j, 0] * p1.z + subdivision[j, 1] * p2.z + subdivision[j, 2] * p3.z;
tempVerts[j].Normalize();
if (!vertDict.TryGetValue(tempVerts[j], out vertIndex)) // quick lookup to avoid vertex duplication
{
vertDict[tempVerts[j]] = index; // if vertex not in dict, add it to dictionary and final array
vertIndex = index;
vertices[index] = tempVerts[j];
index += 1;
}
tempIndices[j] = vertIndex; // assemble vertex indices for triangle assignment
}
for (int j = 0; j < triLength; j++) // map precalculated subdivided triangle indices to vertex indices
{
triangles[triLength * i + j, 0] = tempIndices[triIndices[j, 0]];
triangles[triLength * i + j, 1] = tempIndices[triIndices[j, 1]];
triangles[triLength * i + j, 2] = tempIndices[triIndices[j, 2]];
triangleIndices[3 * triLength * i + 3 * j] = tempIndices[triIndices[j, 0]];
triangleIndices[3 * triLength * i + 3 * j + 1] = tempIndices[triIndices[j, 1]];
triangleIndices[3 * triLength * i + 3 * j + 2] = tempIndices[triIndices[j, 2]];
}
}
}