public SoftwareTriangle(int index, SoftwareVertex vertex1, SoftwareVertex vertex2, SoftwareVertex vertex3)
{
Index = index;
Verticies = new SoftwareVertex[3] {vertex1, vertex2, vertex3};
vertex1.Triangles.Add(this);
vertex2.Triangles.Add(this);
vertex3.Triangles.Add(this);
vertex1.TraingleIndex.Add(0);
vertex2.TraingleIndex.Add(1);
vertex3.TraingleIndex.Add(2);
}