//
// -----o------
//
// Remove boundary vertices with two edge (one ingoing + one outgoing) where edges are parallel
// Remove non-boundary vertices with only two adjacent faces where edges are parallel
//
// The method undo edge split by removing the extra vertex
public static int DissolveUnneededVertices(HMesh hmesh)
{
int count = 0;
foreach (var vert in hmesh.GetVertices())
{
var circ = vert.Circulate();
double parallelEpsilon = 1E-15;
if (vert.IsBoundary() && circ.Count == 1 && VertexDistOnDissolve(vert, circ[0].vert, circ[0].prev.prev.vert) < hmesh.zeroMagnitudeTreshold)
{
vert.Dissolve();
count++;
}
else if (!vert.IsBoundary() && circ.Count == 2)
{
if (VertexDistOnDissolve(vert, circ[0].vert, circ[1].vert) < hmesh.zeroMagnitudeTreshold)
{
vert.Dissolve();
count++;
}
}
}
return(count);
}
public void ApplyTransform()
{
var localToWorld = transform.localToWorldMatrix;
foreach (var vert in hmesh.GetVertices())
{
vert.position = localToWorld.MultiplyPoint(vert.position);
}
transform.position = Vector3.zero;
transform.localScale = Vector3.one;
transform.rotation = Quaternion.identity;
}
void OnGUI()
{
if (GUI.Button(new Rect(0,0,200,50), "FaceSplit")){
HMesh hMesh = new HMesh();
var mf = GetComponent<MeshFilter>();
hMesh.Build(mf.mesh);
foreach (var f in hMesh.GetFaces()){
f.Split();
}
var mesh = hMesh.Export();
mesh.RecalculateNormals();
mf.mesh = mesh;
}
if (GUI.Button(new Rect(200,0,200,50), "EdgeFlip")){
HMesh hMesh = new HMesh();
var mf = GetComponent<MeshFilter>();
hMesh.Build(mf.mesh);
HashSet<Halfedge> isFlipped = new HashSet<Halfedge>();
foreach (var h in hMesh.GetHalfedges()){
if (!h.IsBoundary() && !isFlipped.Contains(h)){
Debug.DrawLine(h.vert.position, h.prev.vert.position,Color.cyan,5);
h.Flip();
isFlipped.Add(h.opp);
}
}
var mesh = hMesh.Export();
mesh.RecalculateNormals();
mf.mesh = mesh;
}
if (GUI.Button(new Rect(400,0,200,50), "EdgeSplit")){
HMesh hMesh = new HMesh();
var mf = GetComponent<MeshFilter>();
hMesh.Build(mf.mesh);
HashSet<Halfedge> isSplit = new HashSet<Halfedge>();
foreach (var h in hMesh.GetHalfedges()){
if (!h.IsBoundary() && !isSplit.Contains(h)){
Debug.DrawLine(h.vert.position, h.prev.vert.position,Color.cyan,5);
isSplit.Add(h.opp);
h.Split();
}
}
var mesh = hMesh.Export();
mesh.RecalculateNormals();
mf.mesh = mesh;
}
if (GUI.Button(new Rect(600,0,200,50), "CollapseEdge")){
HMesh hMesh = new HMesh();
var mf = GetComponent<MeshFilter>();
hMesh.Build(mf.mesh);
HashSet<Halfedge> isCollapsed = new HashSet<Halfedge>();
foreach (var h in hMesh.GetHalfedges()){
if (!h.IsBoundary()){
if (!h.vert.IsBoundary() && !h.prev.vert.IsBoundary() && !isCollapsed.Contains(h)){
Debug.DrawLine(h.vert.position, h.prev.vert.position,Color.cyan,5);
isCollapsed.Add(h.opp);
h.Collapse();
break;
}
}
}
var mesh = hMesh.Export();
mesh.RecalculateNormals();
mf.mesh = mesh;
}
if (GUI.Button(new Rect(0,50,200,50), "CirculateRndVertex")){
HMesh hMesh = new HMesh();
var mf = GetComponent<MeshFilter>();
hMesh.Build(mf.mesh);
HashSet<Halfedge> isCollapsed = new HashSet<Halfedge>();
var vertices = new List<Vertex>(hMesh.GetVertices());
var vertex = vertices[1];//Random.Range(0,vertices.Count-1)];
foreach (var h in vertex.Circulate()){
Debug.DrawLine(h.vert.position, h.prev.vert.position,Color.cyan,5);
}
Debug.Log("Circulate vertex: "+vertex.Circulate().Count);
}
if (GUI.Button(new Rect(200,50,200,50), "CirculateOppRndVertex")){
HMesh hMesh = new HMesh();
var mf = GetComponent<MeshFilter>();
hMesh.Build(mf.mesh);
//HashSet<Halfedge> isCollapsed = new HashSet<Halfedge>();
var vertices = new List<Vertex>(hMesh.GetVertices());
var vertex = vertices[1];//Random.Range(0,vertices.Count-1)];
foreach (var h in vertex.CirculateOpp()){
Debug.DrawLine(h.vert.position, h.prev.vert.position,Color.cyan,5);
}
Debug.Log("Circulate vertex: "+vertex.Circulate().Count);
}
if (GUI.Button(new Rect(400,50,200,50), "Circulate1RingRndVertex")){
HMesh hMesh = new HMesh();
var mf = GetComponent<MeshFilter>();
hMesh.Build(mf.mesh);
// HashSet<Halfedge> isCollapsed = new HashSet<Halfedge>();
var vertices = new List<Vertex>(hMesh.GetVertices());
var vertex = vertices[Random.Range(0,vertices.Count-1)];
foreach (var h in vertex.CirculateOneRing()){
Debug.DrawLine(h.vert.position, h.prev.vert.position,Color.cyan,5);
}
Debug.Log("Circulate 1-ring: "+vertex.CirculateOneRing().Count);
}
if (GUI.Button(new Rect(600,50,200,50), "CirculateRndFace")){
HMesh hMesh = new HMesh();
var mf = GetComponent<MeshFilter>();
hMesh.Build(mf.mesh);
HashSet<Halfedge> isCollapsed = new HashSet<Halfedge>();
var faces = new List<Face>(hMesh.GetFaces());
var face = faces[Random.Range(0,faces.Count-1)];
foreach (var h in face.Circulate()){
Debug.DrawLine(h.vert.position, h.prev.vert.position, Color.cyan, 5);
}
Debug.Log("Circulate face: "+face.Circulate().Count);
}
}
void OnGUI()
{
if (GUI.Button(new Rect(0, 0, 200, 50), "FaceSplit"))
{
HMesh hMesh = new HMesh();
var mf = GetComponent <MeshFilter>();
hMesh.Build(mf.mesh);
foreach (var f in hMesh.GetFaces())
{
f.Split();
}
var mesh = hMesh.Export();
mesh.RecalculateNormals();
mf.mesh = mesh;
}
if (GUI.Button(new Rect(200, 0, 200, 50), "EdgeFlip"))
{
HMesh hMesh = new HMesh();
var mf = GetComponent <MeshFilter>();
hMesh.Build(mf.mesh);
HashSet <Halfedge> isFlipped = new HashSet <Halfedge>();
foreach (var h in hMesh.GetHalfedges())
{
if (!h.IsBoundary() && !isFlipped.Contains(h))
{
Debug.DrawLine(h.vert.position, h.prev.vert.position, Color.cyan, 5);
h.Flip();
isFlipped.Add(h.opp);
}
}
var mesh = hMesh.Export();
mesh.RecalculateNormals();
mf.mesh = mesh;
}
if (GUI.Button(new Rect(400, 0, 200, 50), "EdgeSplit"))
{
HMesh hMesh = new HMesh();
var mf = GetComponent <MeshFilter>();
hMesh.Build(mf.mesh);
HashSet <Halfedge> isSplit = new HashSet <Halfedge>();
foreach (var h in hMesh.GetHalfedges())
{
if (!h.IsBoundary() && !isSplit.Contains(h))
{
Debug.DrawLine(h.vert.position, h.prev.vert.position, Color.cyan, 5);
isSplit.Add(h.opp);
h.Split();
}
}
var mesh = hMesh.Export();
mesh.RecalculateNormals();
mf.mesh = mesh;
}
if (GUI.Button(new Rect(600, 0, 200, 50), "CollapseEdge"))
{
HMesh hMesh = new HMesh();
var mf = GetComponent <MeshFilter>();
hMesh.Build(mf.mesh);
HashSet <Halfedge> isCollapsed = new HashSet <Halfedge>();
foreach (var h in hMesh.GetHalfedges())
{
if (!h.IsBoundary())
{
if (!h.vert.IsBoundary() && !h.prev.vert.IsBoundary() && !isCollapsed.Contains(h))
{
Debug.DrawLine(h.vert.position, h.prev.vert.position, Color.cyan, 5);
isCollapsed.Add(h.opp);
h.Collapse();
break;
}
}
}
var mesh = hMesh.Export();
mesh.RecalculateNormals();
mf.mesh = mesh;
}
if (GUI.Button(new Rect(0, 50, 200, 50), "CirculateRndVertex"))
{
HMesh hMesh = new HMesh();
var mf = GetComponent <MeshFilter>();
hMesh.Build(mf.mesh);
HashSet <Halfedge> isCollapsed = new HashSet <Halfedge>();
var vertices = new List <Vertex>(hMesh.GetVertices());
var vertex = vertices[1]; //Random.Range(0,vertices.Count-1)];
foreach (var h in vertex.Circulate())
{
Debug.DrawLine(h.vert.position, h.prev.vert.position, Color.cyan, 5);
}
Debug.Log("Circulate vertex: " + vertex.Circulate().Count);
}
if (GUI.Button(new Rect(200, 50, 200, 50), "CirculateOppRndVertex"))
{
HMesh hMesh = new HMesh();
var mf = GetComponent <MeshFilter>();
hMesh.Build(mf.mesh);
//HashSet<Halfedge> isCollapsed = new HashSet<Halfedge>();
var vertices = new List <Vertex>(hMesh.GetVertices());
var vertex = vertices[1]; //Random.Range(0,vertices.Count-1)];
foreach (var h in vertex.CirculateOpp())
{
Debug.DrawLine(h.vert.position, h.prev.vert.position, Color.cyan, 5);
}
Debug.Log("Circulate vertex: " + vertex.Circulate().Count);
}
if (GUI.Button(new Rect(400, 50, 200, 50), "Circulate1RingRndVertex"))
{
HMesh hMesh = new HMesh();
var mf = GetComponent <MeshFilter>();
hMesh.Build(mf.mesh);
// HashSet<Halfedge> isCollapsed = new HashSet<Halfedge>();
var vertices = new List <Vertex>(hMesh.GetVertices());
var vertex = vertices[Random.Range(0, vertices.Count - 1)];
foreach (var h in vertex.CirculateOneRing())
{
Debug.DrawLine(h.vert.position, h.prev.vert.position, Color.cyan, 5);
}
Debug.Log("Circulate 1-ring: " + vertex.CirculateOneRing().Count);
}
if (GUI.Button(new Rect(600, 50, 200, 50), "CirculateRndFace"))
{
HMesh hMesh = new HMesh();
var mf = GetComponent <MeshFilter>();
hMesh.Build(mf.mesh);
HashSet <Halfedge> isCollapsed = new HashSet <Halfedge>();
var faces = new List <Face>(hMesh.GetFaces());
var face = faces[Random.Range(0, faces.Count - 1)];
foreach (var h in face.Circulate())
{
Debug.DrawLine(h.vert.position, h.prev.vert.position, Color.cyan, 5);
}
Debug.Log("Circulate face: " + face.Circulate().Count);
}
}
// return the number of collapsed faces
public static int SimplifyByCollapse(HMesh hmesh, int maxIter = int.MaxValue)
{
List <Halfedge> faceLabelBoundary = new List <Halfedge>();
int collapsed = 0;
bool changed;
int iter = 0;
int collapsedEven = 0;
do
{
iter++;
changed = false;
// collapse he if vertex contains two parallel halfedges, which separates labels or is boundary)
foreach (var vert in hmesh.GetVertices())
{
if (vert.IsDestroyed())
{
continue;
}
if (vert.IsBoundary())
{
// boundary collapses should be handled by DissolveUnneededBoundaryVertices
continue;
}
faceLabelBoundary.Clear();
var vertCirculate = vert.Circulate();
foreach (var he in vertCirculate)
{
if (he.face.label != he.opp.face.label)
{
faceLabelBoundary.Add(he);
}
}
if (faceLabelBoundary.Count == 1)
{
Debug.Assert(false, "Cannot have a single face label boundary (without the vertex is a boundary");
}
else if (faceLabelBoundary.Count == 2)
{
var dirs = new[] { faceLabelBoundary[0].GetDirection(), faceLabelBoundary[1].GetDirection() };
var line = new LineSegment(faceLabelBoundary[0].vert.positionD, faceLabelBoundary[1].vert.positionD);
double distance = line.DistancePoint(faceLabelBoundary[0].prev.vert.positionD);
double distThreshold = hmesh.zeroMagnitudeTreshold;
var dot = Vector3D.Dot(dirs[0], dirs[1]);
bool sameDir = dot < 0.0;
if (distance < distThreshold && sameDir)
{
var position = faceLabelBoundary[0].vert.positionD;
if (IsFacesOnSamePlane(hmesh, vertCirculate, faceLabelBoundary[0].face.label) && IsFacesOnSamePlane(hmesh, vertCirculate, faceLabelBoundary[1].face.label))
{
if (PreconditionLegalCollapse(faceLabelBoundary[0], position))
{
//if (PreconditionLegalCollapse(faceLabelBoundary[0])){
var newVertex = faceLabelBoundary[0].Collapse(faceLabelBoundary[0].vert.positionD);
if (newVertex != null)
{
newVertex.positionD = position;
}
collapsed++;
changed = true;
#if HMDebug
if (!hmesh.IsValid())
{
Debug.Log("Invalid");
}
#endif
if (debugOneStep)
{
return(-1);
}
}
else if (PreconditionLegalCollapse(faceLabelBoundary[1], position))
{
var newVertex = faceLabelBoundary[1].Collapse(faceLabelBoundary[1].vert.positionD);
if (newVertex != null)
{
newVertex.positionD = position;
}
collapsed++;
changed = true;
#if HMDebug
if (!hmesh.IsValid())
{
Debug.Log("Invalid");
}
#endif
if (debugOneStep)
{
return(-1);
}
}
}
}
}
else if (faceLabelBoundary.Count == 0)
{
if (IsFacesOnSamePlane(hmesh, vertCirculate))
{
// search for which to collapse (should not result in flipped vectors)
for (int i = 0; i < vertCirculate.Count; i++)
{
#if HMDebug
if (!hmesh.IsValid())
{
Debug.LogError("PreInvalid");
}
#endif
if (PreconditionLegalCollapse(vertCirculate[i], vertCirculate[i].vert.positionD))
{
var collapseStr = vertCirculate[i].ToString();
var position = vertCirculate[i].vert.positionD;
var newVertex = vertCirculate[i].Collapse();
collapsed++;
newVertex.positionD = position;
#if HMDebug
if (!hmesh.IsValid())
{
Debug.Log("Invalid");
Debug.LogError(collapseStr);
}
#endif
i = int.MaxValue - 1;
if (debugOneStep)
{
return(-1);
}
break;
}
}
}
}
}
} while (changed && iter < maxIter);
return(collapsed);
}
