public virtual bool Extrude(int group_id = -1)
{
// duplicate loop vertices
int NV = Loop.Vertices.Length;
NewLoop = new EdgeLoop(Mesh);
NewLoop.Vertices = new int[NV];
for (int i = 0; i < NV; ++i)
{
int vid = Loop.Vertices[i];
NewLoop.Vertices[i] = Mesh.AppendVertex(Mesh, vid);
}
// move to offset positions
for (int i = 0; i < NV; ++i)
{
Vector3D v = Mesh.GetVertex(Loop.Vertices[i]);
Vector3F n = Mesh.GetVertexNormal(Loop.Vertices[i]);
Vector3D new_v = PositionF(v, n, i);
Mesh.SetVertex(NewLoop.Vertices[i], new_v);
}
// stitch interior
MeshEditor edit = new MeshEditor(Mesh);
NewTriangles = edit.StitchLoop(Loop.Vertices, NewLoop.Vertices, group_id);
return(true);
}
public virtual bool Smooth()
{
int NV = Loop.Vertices.Length;
double a = math.MathUtil.Clamp(Alpha, 0, 1);
double num_rounds = math.MathUtil.Clamp(Rounds, 0, 10000);
for (int round = 0; round < num_rounds; ++round)
{
// compute
gParallel.ForEach(Interval1i.Range(NV), (i) => {
int vid = Loop.Vertices[(i + 1) % NV];
Vector3D prev = Mesh.GetVertex(Loop.Vertices[i]);
Vector3D cur = Mesh.GetVertex(vid);
Vector3D next = Mesh.GetVertex(Loop.Vertices[(i + 2) % NV]);
Vector3D centroid = (prev + next) * 0.5;
SmoothedPostions[i] = (1 - a) * cur + (a) * centroid;
});
// bake
gParallel.ForEach(Interval1i.Range(NV), (i) => {
int vid = Loop.Vertices[(i + 1) % NV];
Vector3D pos = SmoothedPostions[i];
if (ProjectF != null)
{
pos = ProjectF(pos, vid);
}
Mesh.SetVertex(vid, pos);
});
}
return(true);
}
public virtual bool Cut()
{
double invalidDist = double.MinValue;
// compute signs
int MaxVID = Mesh.MaxVertexID;
double[] signs = new double[MaxVID];
gParallel.ForEach(Interval1i.Range(MaxVID), (vid) => {
if (Mesh.IsVertex(vid))
{
Vector3D v = Mesh.GetVertex(vid);
signs[vid] = (v - PlaneOrigin).Dot(PlaneNormal);
}
else
{
signs[vid] = invalidDist;
}
});
HashSet <int> ZeroEdges = new HashSet <int>();
HashSet <int> ZeroVertices = new HashSet <int>();
HashSet <int> OnCutEdges = new HashSet <int>();
// have to skip processing of new edges. If edge id
// is > max at start, is new. Otherwise if in NewEdges list, also new.
int MaxEID = Mesh.MaxEdgeID;
HashSet <int> NewEdges = new HashSet <int>();
// cut existing edges with plane, using edge split
for (int eid = 0; eid < MaxEID; ++eid)
{
if (Mesh.IsEdge(eid) == false)
{
continue;
}
if (eid >= MaxEID || NewEdges.Contains(eid))
{
continue;
}
Index2i ev = Mesh.GetEdgeV(eid);
double f0 = signs[ev.a];
double f1 = signs[ev.b];
// If both signs are 0, this edge is on-contour
// If one sign is 0, that vertex is on-contour
int n0 = (Math.Abs(f0) < math.MathUtil.Epsilon) ? 1 : 0;
int n1 = (Math.Abs(f1) < math.MathUtil.Epsilon) ? 1 : 0;
if (n0 + n1 > 0)
{
if (n0 + n1 == 2)
{
ZeroEdges.Add(eid);
}
else
{
ZeroVertices.Add((n0 == 1) ? ev[0] : ev[1]);
}
continue;
}
// no crossing
if (f0 * f1 > 0)
{
continue;
}
NGonsCore.geometry3Sharp.mesh.DMesh3.EdgeSplitInfo splitInfo;
MeshResult result = Mesh.SplitEdge(eid, out splitInfo);
if (result != MeshResult.Ok)
{
throw new Exception("MeshPlaneCut.Cut: failed in SplitEdge");
//return false;
}
// SplitEdge just bisects edge - use plane intersection instead
double t = f0 / (f0 - f1);
Vector3D newPos = (1 - t) * Mesh.GetVertex(ev.a) + (t) * Mesh.GetVertex(ev.b);
Mesh.SetVertex(splitInfo.vNew, newPos);
NewEdges.Add(splitInfo.eNewBN);
NewEdges.Add(splitInfo.eNewCN); OnCutEdges.Add(splitInfo.eNewCN);
if (splitInfo.eNewDN != NGonsCore.geometry3Sharp.mesh.DMesh3.InvalidID)
{
NewEdges.Add(splitInfo.eNewDN);
OnCutEdges.Add(splitInfo.eNewDN);
}
}
// remove one-rings of all positive-side vertices.
for (int i = 0; i < signs.Length; ++i)
{
if (signs[i] > 0 && Mesh.IsVertex(i))
{
Mesh.RemoveVertex(i, true, false);
}
}
// ok now we extract boundary loops, but restricted
// to either the zero-edges we found, or the edges we created! bang!!
Func <int, bool> CutEdgeFilterF = (eid) => {
if (OnCutEdges.Contains(eid) || ZeroEdges.Contains(eid))
{
return(true);
}
return(false);
};
try {
MeshBoundaryLoops loops = new MeshBoundaryLoops(Mesh, false);
loops.EdgeFilterF = CutEdgeFilterF;
loops.Compute();
CutLoops = loops.Loops;
CutLoopsFailed = false;
} catch {
CutLoops = new List <EdgeLoop>();
CutLoopsFailed = true;
}
return(true);
} // Cut()