/// <summary>
///
/// </summary>
private static void CatmullClarkSmooth <V, E, F>(HeMeshBase <V, E, F> mesh, Property <V, Vec3d> position, SmoothBoundaryType boundaryType)
where V : HeVertex <V, E, F>
where E : Halfedge <V, E, F>
where F : HeFace <V, E, F>
{
switch (boundaryType)
{
case SmoothBoundaryType.Fixed:
CatmullClarkSmoothFixed(mesh, position);
return;
case SmoothBoundaryType.CornerFixed:
CatmullClarkSmoothCornerFixed(mesh, position);
return;
case SmoothBoundaryType.Free:
CatmullClarkSmoothFree(mesh, position);
return;
}
throw new NotSupportedException();
}
/// <summary>
/// Applies a single iteration of Catmull-Clark subdivision to the given mesh.
/// If using external buffers to store vertex attributes, the number of vertices after subdivision equals the sum of the number of vertices edges and faces in the initial mesh.
/// http://rosettacode.org/wiki/Catmull%E2%80%93Clark_subdivision_surface
/// http://w3.impa.br/~lcruz/courses/cma/surfaces.html
/// </summary>
/// <typeparam name="V"></typeparam>
/// <typeparam name="E"></typeparam>
/// <typeparam name="F"></typeparam>
/// <param name="mesh"></param>
/// <param name="position"></param>
/// <param name="boundaryType"></param>
public static void CatmullClark <V, E, F>(HeMeshBase <V, E, F> mesh, Property <V, Vec3d> position, SmoothBoundaryType boundaryType)
where V : HeVertex <V, E, F>
where E : Halfedge <V, E, F>
where F : HeFace <V, E, F>
{
CatmullClarkGeometry(mesh, position, boundaryType);
QuadSplitTopology(mesh);
}
/// <summary>
///
/// </summary>
/// <typeparam name="V"></typeparam>
/// <typeparam name="E"></typeparam>
/// <typeparam name="F"></typeparam>
/// <param name="mesh"></param>
/// <param name="position"></param>
/// <param name="boundaryType"></param>
private static void CatmullClarkGeometry <V, E, F>(HeMeshBase <V, E, F> mesh, Property <V, Vec3d> position, SmoothBoundaryType boundaryType)
where V : HeVertex <V, E, F>
where E : Halfedge <V, E, F>
where F : HeFace <V, E, F>
{
var verts = mesh.Vertices;
int fv0 = verts.Count; // index of first face vertex
// create face vertices
foreach (var f in mesh.Faces)
{
var v = mesh.AddVertex();
if (!f.IsRemoved)
{
position.Set(v, f.Vertices.Mean(position.Get));
}
}
// create edge vertices
foreach (var he0 in mesh.Edges)
{
var v = mesh.AddVertex();
if (he0.IsRemoved)
{
continue;
}
if (he0.IsBoundary)
{
position.Set(v, he0.Lerp(position.Get, 0.5));
continue;
}
var he1 = he0.Twin;
var p0 = position.Get(he0.Start);
var p1 = position.Get(he1.Start);
var p2 = position.Get(verts[he0.Face.Index + fv0]);
var p3 = position.Get(verts[he1.Face.Index + fv0]);
position.Set(v, (p0 + p1 + p2 + p3) * 0.25);
}
// smooth old vertices
CatmullClarkSmooth(mesh, position, boundaryType);
}
/// <summary>
/// Applies a single iteration of Catmull-Clark subdivision to the given mesh.
/// If using external buffers to store vertex attributes, the number of vertices after subdivision equals the sum of the number of vertices, edges, and faces in the initial mesh.
/// </summary>
/// <typeparam name="V"></typeparam>
/// <typeparam name="E"></typeparam>
/// <typeparam name="F"></typeparam>
/// <param name="mesh"></param>
/// <param name="position"></param>
/// <param name="boundaryType"></param>
public static void CatmullClark <V, E, F>(HeMesh <V, E, F> mesh, Property <V, Vec3d> position, SmoothBoundaryType boundaryType)
where V : HeMesh <V, E, F> .Vertex
where E : HeMesh <V, E, F> .Halfedge
where F : HeMesh <V, E, F> .Face
{
// impl ref
// http://rosettacode.org/wiki/Catmull%E2%80%93Clark_subdivision_surface
// http://w3.impa.br/~lcruz/courses/cma/surfaces.html
CatmullClarkGeometry(mesh, position, boundaryType);
QuadSplitTopology(mesh);
}