// Naive feature detection. All boundary edges with angle > featureAngle become
// feature edges. All points on feature edges become feature points. All
// boundary faces become feature faces.
void simpleMarkFeatures
(
const polyMesh& mesh,
const PackedBoolList& isBoundaryEdge,
const scalar featureAngle,
const bool concaveMultiCells,
const bool doNotPreserveFaceZones,
labelList& featureFaces,
labelList& featureEdges,
labelList& singleCellFeaturePoints,
labelList& multiCellFeaturePoints
)
{
scalar minCos = Foam::cos(featureAngle * mathematicalConstant::pi/180.0);
const polyBoundaryMesh& patches = mesh.boundaryMesh();
// Working sets
labelHashSet featureEdgeSet;
labelHashSet singleCellFeaturePointSet;
labelHashSet multiCellFeaturePointSet;
// 1. Mark all edges between patches
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
forAll(patches, patchI)
{
const polyPatch& pp = patches[patchI];
const labelList& meshEdges = pp.meshEdges();
// All patch corner edges. These need to be feature points & edges!
for (label edgeI = pp.nInternalEdges(); edgeI < pp.nEdges(); edgeI++)
{
label meshEdgeI = meshEdges[edgeI];
featureEdgeSet.insert(meshEdgeI);
singleCellFeaturePointSet.insert(mesh.edges()[meshEdgeI][0]);
singleCellFeaturePointSet.insert(mesh.edges()[meshEdgeI][1]);
}
}
// 2. Mark all geometric feature edges
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// Make distinction between convex features where the boundary point becomes
// a single cell and concave features where the boundary point becomes
// multiple 'half' cells.
// Addressing for all outside faces
primitivePatch allBoundary
(
SubList<face>
(
mesh.faces(),
mesh.nFaces()-mesh.nInternalFaces(),
mesh.nInternalFaces()
),
mesh.points()
);
// Check for non-manifold points (surface pinched at point)
allBoundary.checkPointManifold(false, &singleCellFeaturePointSet);
// Check for non-manifold edges (surface pinched at edge)
const labelListList& edgeFaces = allBoundary.edgeFaces();
const labelList& meshPoints = allBoundary.meshPoints();
forAll(edgeFaces, edgeI)
{
const labelList& eFaces = edgeFaces[edgeI];
if (eFaces.size() > 2)
{
const edge& e = allBoundary.edges()[edgeI];
//Info<< "Detected non-manifold boundary edge:" << edgeI
// << " coords:"
// << allBoundary.points()[meshPoints[e[0]]]
// << allBoundary.points()[meshPoints[e[1]]] << endl;
singleCellFeaturePointSet.insert(meshPoints[e[0]]);
singleCellFeaturePointSet.insert(meshPoints[e[1]]);
}
}
// Check for features.
forAll(edgeFaces, edgeI)
{
const labelList& eFaces = edgeFaces[edgeI];
if (eFaces.size() == 2)
{
label f0 = eFaces[0];
label f1 = eFaces[1];
// check angle
const vector& n0 = allBoundary.faceNormals()[f0];
const vector& n1 = allBoundary.faceNormals()[f1];
if ((n0 & n1) < minCos)
{
const edge& e = allBoundary.edges()[edgeI];
label v0 = meshPoints[e[0]];
label v1 = meshPoints[e[1]];
label meshEdgeI = meshTools::findEdge(mesh, v0, v1);
featureEdgeSet.insert(meshEdgeI);
// Check if convex or concave by looking at angle
// between face centres and normal
vector c1c0
(
allBoundary[f1].centre(allBoundary.points())
- allBoundary[f0].centre(allBoundary.points())
);
if (concaveMultiCells && (c1c0 & n0) > SMALL)
{
// Found concave edge. Make into multiCell features
Info<< "Detected concave feature edge:" << edgeI
<< " cos:" << (c1c0 & n0)
<< " coords:"
<< allBoundary.points()[v0]
<< allBoundary.points()[v1]
<< endl;
singleCellFeaturePointSet.erase(v0);
multiCellFeaturePointSet.insert(v0);
singleCellFeaturePointSet.erase(v1);
multiCellFeaturePointSet.insert(v1);
}
else
{
// Convex. singleCell feature.
if (!multiCellFeaturePointSet.found(v0))
{
singleCellFeaturePointSet.insert(v0);
}
if (!multiCellFeaturePointSet.found(v1))
{
singleCellFeaturePointSet.insert(v1);
}
}
}
}
}
// 3. Mark all feature faces
// ~~~~~~~~~~~~~~~~~~~~~~~~~
// Face centres that need inclusion in the dual mesh
labelHashSet featureFaceSet(mesh.nFaces()-mesh.nInternalFaces());
// A. boundary faces.
for (label faceI = mesh.nInternalFaces(); faceI < mesh.nFaces(); faceI++)
{
featureFaceSet.insert(faceI);
}
// B. face zones.
const faceZoneMesh& faceZones = mesh.faceZones();
if (doNotPreserveFaceZones)
{
if (faceZones.size() > 0)
{
WarningIn("simpleMarkFeatures(..)")
<< "Detected " << faceZones.size()
<< " faceZones. These will not be preserved."
<< endl;
}
}
else
{
if (faceZones.size() > 0)
{
Info<< "Detected " << faceZones.size()
<< " faceZones. Preserving these by marking their"
<< " points, edges and faces as features." << endl;
}
forAll(faceZones, zoneI)
{
const faceZone& fz = faceZones[zoneI];
Info<< "Inserting all faces in faceZone " << fz.name()
<< " as features." << endl;
forAll(fz, i)
{
label faceI = fz[i];
const face& f = mesh.faces()[faceI];
const labelList& fEdges = mesh.faceEdges()[faceI];
featureFaceSet.insert(faceI);
forAll(f, fp)
{
// Mark point as multi cell point (since both sides of
// face should have different cells)
singleCellFeaturePointSet.erase(f[fp]);
multiCellFeaturePointSet.insert(f[fp]);
// Make sure there are points on the edges.
featureEdgeSet.insert(fEdges[fp]);
}
}
}
