public virtual bool Trim()
{
if (Spatial == null)
{
Spatial = new DMeshAABBTree3(new DMesh3(Mesh, false, MeshComponents.None));
Spatial.Build();
}
if (seed_tri == -1)
{
seed_tri = Spatial.FindNearestTriangle(seed_pt);
}
var loop = new MeshFacesFromLoop(Mesh, TrimLine, Spatial, seed_tri);
MeshFaceSelection selection = loop.ToSelection();
selection.LocalOptimize(true, true);
var editor = new MeshEditor(Mesh);
editor.RemoveTriangles(selection, true);
var components = new MeshConnectedComponents(Mesh);
components.FindConnectedT();
if (components.Count > 1)
{
int keep = components.LargestByCount;
for (int i = 0; i < components.Count; ++i)
{
if (i != keep)
{
editor.RemoveTriangles(components[i].Indices, true);
}
}
}
editor.RemoveAllBowtieVertices(true);
var loops = new MeshBoundaryLoops(Mesh);
bool loopsOK = false;
try
{
loopsOK = loops.Compute();
}
catch (Exception)
{
return(false);
}
if (!loopsOK)
{
return(false);
}
// [TODO] to support trimming mesh w/ existing holes, we need to figure out which
// loop we created in RemoveTriangles above!
if (loops.Count > 1)
{
return(false);
}
int[] loopVerts = loops[0].Vertices;
var borderTris = new MeshFaceSelection(Mesh);
borderTris.SelectVertexOneRings(loopVerts);
borderTris.ExpandToOneRingNeighbours(RemeshBorderRings);
var remesh = new RegionRemesher(Mesh, borderTris.ToArray());
remesh.Region.MapVerticesToSubmesh(loopVerts);
double target_len = TargetEdgeLength;
if (target_len <= 0)
{
double mine, maxe, avge;
MeshQueries.EdgeLengthStatsFromEdges(Mesh, loops[0].Edges, out mine, out maxe, out avge);
target_len = avge;
}
var meshTarget = new MeshProjectionTarget(Spatial.Mesh, Spatial);
remesh.SetProjectionTarget(meshTarget);
remesh.SetTargetEdgeLength(target_len);
remesh.SmoothSpeedT = SmoothingAlpha;
var curveTarget = new DCurveProjectionTarget(TrimLine);
var multiTarget = new SequentialProjectionTarget(curveTarget, meshTarget);
int set_id = 3;
MeshConstraintUtil.ConstrainVtxLoopTo(remesh, loopVerts, multiTarget, set_id);
for (int i = 0; i < RemeshRounds; ++i)
{
remesh.BasicRemeshPass();
}
remesh.BackPropropagate();
// [TODO] output loop somehow...use MeshConstraints.FindConstrainedEdgesBySetID(set_id)...
return(true);
} // Trim()
public virtual bool Cut()
{
double invalidDist = double.MinValue;
MeshEdgeSelection CutEdgeSet = null;
MeshVertexSelection CutVertexSet = null;
if (CutFaceSet != null)
{
CutEdgeSet = new MeshEdgeSelection(Mesh, CutFaceSet);
CutVertexSet = new MeshVertexSelection(Mesh, CutEdgeSet);
}
// 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>();
IEnumerable <int> edgeItr = Interval1i.Range(MaxEID);
if (CutEdgeSet != null)
{
edgeItr = CutEdgeSet;
}
// cut existing edges with plane, using edge split
foreach (int eid in edgeItr)
{
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) < MathUtil.Epsilon) ? 1 : 0;
int n1 = (Math.Abs(f1) < 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;
}
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 != DMesh3.InvalidID)
{
NewEdges.Add(splitInfo.eNewDN);
OnCutEdges.Add(splitInfo.eNewDN);
}
}
// remove one-rings of all positive-side vertices.
IEnumerable <int> vertexSet = Interval1i.Range(MaxVID);
if (CutVertexSet != null)
{
vertexSet = CutVertexSet;
}
foreach (int vid in vertexSet)
{
if (signs[vid] > 0 && Mesh.IsVertex(vid))
{
Mesh.RemoveVertex(vid, 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;
CutSpans = loops.Spans;
CutLoopsFailed = false;
FoundOpenSpans = CutSpans.Count > 0;
} catch {
CutLoops = new List <EdgeLoop>();
CutLoopsFailed = true;
}
return(true);
} // Cut()
