public MeshGeometry3D Create(int recursionLevel)
{
this.geometry = new MeshGeometry3D ();
this.middlePointIndexCache = new Dictionary<long, int> ();
this.index = 0;
// create 12 vertices of a icosahedron
float t = (float)((1.0f + Math.Sqrt (5.0)) / 2.0);
addVertex (new Vector3 (-1, t, 0f));
addVertex (new Vector3 (1, t, 0f));
addVertex (new Vector3 (-1, -t, 0f));
addVertex (new Vector3 (1, -t, 0f));
addVertex (new Vector3 (0, -1, t));
addVertex (new Vector3 (0, 1, t));
addVertex (new Vector3 (0, -1, -t));
addVertex (new Vector3 (0, 1, -t));
addVertex (new Vector3 (t, 0, -1));
addVertex (new Vector3 (t, 0, 1));
addVertex (new Vector3 (-t, 0, -1));
addVertex (new Vector3 (-t, 0, 1));
// create 20 triangles of the icosahedron
var faces = new List<TriangleIndices> ();
// 5 faces around point 0
faces.Add (new TriangleIndices (0, 11, 5));
faces.Add (new TriangleIndices (0, 5, 1));
faces.Add (new TriangleIndices (0, 1, 7));
faces.Add (new TriangleIndices (0, 7, 10));
faces.Add (new TriangleIndices (0, 10, 11));
// 5 adjacent faces
faces.Add (new TriangleIndices (1, 5, 9));
faces.Add (new TriangleIndices (5, 11, 4));
faces.Add (new TriangleIndices (11, 10, 2));
faces.Add (new TriangleIndices (10, 7, 6));
faces.Add (new TriangleIndices (7, 1, 8));
// 5 faces around point 3
faces.Add (new TriangleIndices (3, 9, 4));
faces.Add (new TriangleIndices (3, 4, 2));
faces.Add (new TriangleIndices (3, 2, 6));
faces.Add (new TriangleIndices (3, 6, 8));
faces.Add (new TriangleIndices (3, 8, 9));
// 5 adjacent faces
faces.Add (new TriangleIndices (4, 9, 5));
faces.Add (new TriangleIndices (2, 4, 11));
faces.Add (new TriangleIndices (6, 2, 10));
faces.Add (new TriangleIndices (8, 6, 7));
faces.Add (new TriangleIndices (9, 8, 1));
// refine triangles
for (int i = 0; i < recursionLevel; i++) {
var faces2 = new List<TriangleIndices> ();
foreach (var tri in faces) {
// replace triangle by 4 triangles
int a = getMiddlePoint (tri.v1, tri.v2);
int b = getMiddlePoint (tri.v2, tri.v3);
int c = getMiddlePoint (tri.v3, tri.v1);
faces2.Add (new TriangleIndices (tri.v1, a, c));
faces2.Add (new TriangleIndices (tri.v2, b, a));
faces2.Add (new TriangleIndices (tri.v3, c, b));
faces2.Add (new TriangleIndices (a, b, c));
}
faces = faces2;
}
this.geometry.Faces = faces;
// done, now add triangles to mesh
foreach (var tri in faces) {
this.geometry.MeshIndicies.Add (tri.v1);
this.geometry.MeshIndicies.Add (tri.v2);
this.geometry.MeshIndicies.Add (tri.v3);
}
return this.geometry;
}
public MeshGeometry3D Create(int recursionLevel)
{
this.geometry = new MeshGeometry3D();
this.middlePointIndexCache = new Dictionary <long, int> ();
this.index = 0;
// create 12 vertices of a icosahedron
float t = (float)((1.0f + Math.Sqrt(5.0)) / 2.0);
addVertex(new Vector3(-1, t, 0f));
addVertex(new Vector3(1, t, 0f));
addVertex(new Vector3(-1, -t, 0f));
addVertex(new Vector3(1, -t, 0f));
addVertex(new Vector3(0, -1, t));
addVertex(new Vector3(0, 1, t));
addVertex(new Vector3(0, -1, -t));
addVertex(new Vector3(0, 1, -t));
addVertex(new Vector3(t, 0, -1));
addVertex(new Vector3(t, 0, 1));
addVertex(new Vector3(-t, 0, -1));
addVertex(new Vector3(-t, 0, 1));
// create 20 triangles of the icosahedron
var faces = new List <TriangleIndices> ();
// 5 faces around point 0
faces.Add(new TriangleIndices(0, 11, 5));
faces.Add(new TriangleIndices(0, 5, 1));
faces.Add(new TriangleIndices(0, 1, 7));
faces.Add(new TriangleIndices(0, 7, 10));
faces.Add(new TriangleIndices(0, 10, 11));
// 5 adjacent faces
faces.Add(new TriangleIndices(1, 5, 9));
faces.Add(new TriangleIndices(5, 11, 4));
faces.Add(new TriangleIndices(11, 10, 2));
faces.Add(new TriangleIndices(10, 7, 6));
faces.Add(new TriangleIndices(7, 1, 8));
// 5 faces around point 3
faces.Add(new TriangleIndices(3, 9, 4));
faces.Add(new TriangleIndices(3, 4, 2));
faces.Add(new TriangleIndices(3, 2, 6));
faces.Add(new TriangleIndices(3, 6, 8));
faces.Add(new TriangleIndices(3, 8, 9));
// 5 adjacent faces
faces.Add(new TriangleIndices(4, 9, 5));
faces.Add(new TriangleIndices(2, 4, 11));
faces.Add(new TriangleIndices(6, 2, 10));
faces.Add(new TriangleIndices(8, 6, 7));
faces.Add(new TriangleIndices(9, 8, 1));
// refine triangles
for (int i = 0; i < recursionLevel; i++)
{
var faces2 = new List <TriangleIndices> ();
foreach (var tri in faces)
{
// replace triangle by 4 triangles
int a = getMiddlePoint(tri.v1, tri.v2);
int b = getMiddlePoint(tri.v2, tri.v3);
int c = getMiddlePoint(tri.v3, tri.v1);
faces2.Add(new TriangleIndices(tri.v1, a, c));
faces2.Add(new TriangleIndices(tri.v2, b, a));
faces2.Add(new TriangleIndices(tri.v3, c, b));
faces2.Add(new TriangleIndices(a, b, c));
}
faces = faces2;
}
this.geometry.Faces = faces;
// done, now add triangles to mesh
foreach (var tri in faces)
{
this.geometry.MeshIndicies.Add(tri.v1);
this.geometry.MeshIndicies.Add(tri.v2);
this.geometry.MeshIndicies.Add(tri.v3);
}
return(this.geometry);
}
