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0029715: Mesh - Estimate the grid size of the acceleration structure by the complexity of the face

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The circles acceleration structure sizes are estimated using the required deflection and the complexity of the face.
This commit is contained in:
drazmyslovich 2018-04-23 16:04:29 +03:00 committed by abv
parent 64e93ce135
commit 3e782664b8
5 changed files with 252 additions and 55 deletions
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83
src/BRepMesh/BRepMesh_Delaun.cxx
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@ -106,7 +106,9 @@ BRepMesh_Delaun::BRepMesh_Delaun(
myCircles ( theVertices.Length(), theOldMesh->Allocator() )
{
if ( theVertices.Length() > 2 )
{
Init( theVertices );
}
}
//=======================================================================
@ -119,16 +121,21 @@ BRepMesh_Delaun::BRepMesh_Delaun(
: myMeshData( theOldMesh ),
myCircles ( theVertexIndices.Length(), theOldMesh->Allocator() )
{
if ( theVertexIndices.Length() > 2 )
{
Bnd_Box2d aBox;
Standard_Integer anIndex = theVertexIndices.Lower();
Standard_Integer anUpper = theVertexIndices.Upper();
for ( ; anIndex <= anUpper; ++anIndex )
aBox.Add( gp_Pnt2d( GetVertex( theVertexIndices( anIndex) ).Coord() ) );
perform( theVertexIndices );
}
perform( aBox, theVertexIndices );
}
//=======================================================================
//function : BRepMesh_Delaun
//purpose : Creates the triangulation with and existent Mesh data structure
//=======================================================================
BRepMesh_Delaun::BRepMesh_Delaun (const Handle (BRepMesh_DataStructureOfDelaun)& theOldMesh,
BRepMesh::Array1OfInteger& theVertexIndices,
const Standard_Integer theCellsCountU,
const Standard_Integer theCellsCountV)
: myMeshData (theOldMesh),
myCircles (theVertexIndices.Length (), theOldMesh->Allocator ())
{
perform (theVertexIndices, theCellsCountU, theCellsCountV);
}
//=======================================================================
@ -137,7 +144,6 @@ BRepMesh_Delaun::BRepMesh_Delaun(
//=======================================================================
void BRepMesh_Delaun::Init(BRepMesh::Array1OfVertexOfDelaun& theVertices)
{
Bnd_Box2d aBox;
Standard_Integer aLowerIdx = theVertices.Lower();
Standard_Integer anUpperIdx = theVertices.Upper();
BRepMesh::Array1OfInteger aVertexIndexes( aLowerIdx, anUpperIdx );
@ -145,35 +151,62 @@ void BRepMesh_Delaun::Init(BRepMesh::Array1OfVertexOfDelaun& theVertices)
Standard_Integer anIndex = aLowerIdx;
for ( ; anIndex <= anUpperIdx; ++anIndex )
{
aBox.Add( gp_Pnt2d( theVertices( anIndex ).Coord() ) );
aVertexIndexes( anIndex ) = myMeshData->AddNode( theVertices( anIndex ) );
}
perform( aBox, aVertexIndexes );
perform( aVertexIndexes );
}
//=======================================================================
//function : perform
//purpose : Create super mesh and run triangulation procedure
//=======================================================================
void BRepMesh_Delaun::perform(Bnd_Box2d& theBndBox,
BRepMesh::Array1OfInteger& theVertexIndexes)
void BRepMesh_Delaun::perform (BRepMesh::Array1OfInteger& theVertexIndices,
const Standard_Integer theCellsCountU /* = -1 */,
const Standard_Integer theCellsCountV /* = -1 */)
{
theBndBox.Enlarge( Precision );
superMesh( theBndBox );
if (theVertexIndices.Length () <= 2)
{
return;
}
Bnd_Box2d aBox;
Standard_Integer anIndex = theVertexIndices.Lower ();
Standard_Integer anUpper = theVertexIndices.Upper ();
for (; anIndex <= anUpper; ++anIndex)
{
aBox.Add (gp_Pnt2d (GetVertex (theVertexIndices (anIndex)).Coord ()));
}
aBox.Enlarge (Precision);
Standard_Integer aScaler = 2;
if ( myMeshData->NbNodes() > 100 )
{
aScaler = 5;
}
else if( myMeshData->NbNodes() > 1000 )
{
aScaler = 7;
}
superMesh (aBox, Max (theCellsCountU, aScaler),
Max (theCellsCountV, aScaler));
ComparatorOfIndexedVertexOfDelaun aCmp(myMeshData);
std::make_heap(theVertexIndexes.begin(), theVertexIndexes.end(), aCmp);
std::sort_heap(theVertexIndexes.begin(), theVertexIndexes.end(), aCmp);
std::make_heap(theVertexIndices.begin(), theVertexIndices.end(), aCmp);
std::sort_heap(theVertexIndices.begin(), theVertexIndices.end(), aCmp);
compute( theVertexIndexes );
compute( theVertexIndices );
}
//=======================================================================
//function : superMesh
//purpose : Build the super mesh
//=======================================================================
void BRepMesh_Delaun::superMesh( const Bnd_Box2d& theBox )
void BRepMesh_Delaun::superMesh (const Bnd_Box2d& theBox,
const Standard_Integer theCellsCountU,
const Standard_Integer theCellsCountV)
{
Standard_Real aMinX, aMinY, aMaxX, aMaxY;
theBox.Get( aMinX, aMinY, aMaxX, aMaxY );
@ -185,15 +218,7 @@ void BRepMesh_Delaun::superMesh( const Bnd_Box2d& theBox )
Standard_Real aDelta = aDeltaX + aDeltaY;
myCircles.SetMinMaxSize( gp_XY( aMinX, aMinY ), gp_XY( aMaxX, aMaxY ) );
Standard_Integer aScaler = 2;
if ( myMeshData->NbNodes() > 100 )
aScaler = 5;
else if( myMeshData->NbNodes() > 1000 )
aScaler = 7;
myCircles.SetCellSize( aDeltaX / aScaler,
aDeltaY / aScaler );
myCircles.SetCellSize( aDeltaX / theCellsCountU, aDeltaY / theCellsCountV);
mySupVert[0] = myMeshData->AddNode(
BRepMesh_Vertex( ( aMinX + aMaxX ) / 2, aMaxY + aDeltaMax, BRepMesh_Free ) );

17
src/BRepMesh/BRepMesh_Delaun.hxx
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@ -52,6 +52,12 @@ public:
Standard_EXPORT BRepMesh_Delaun (const Handle(BRepMesh_DataStructureOfDelaun)& theOldMesh,
BRepMesh::Array1OfInteger& theVertexIndices);
//! Creates the triangulation with an existant Mesh data structure.
Standard_EXPORT BRepMesh_Delaun (const Handle (BRepMesh_DataStructureOfDelaun)& theOldMesh,
BRepMesh::Array1OfInteger& theVertexIndices,
const Standard_Integer theCellsCountU,
const Standard_Integer theCellsCountV);
//! Initializes the triangulation with an array of vertices.
Standard_EXPORT void Init (BRepMesh::Array1OfVertexOfDelaun& theVertices);
@ -144,12 +150,15 @@ private:
//! that have number of connected elements less or equal 1.
BRepMesh::HMapOfInteger getEdgesByType (const BRepMesh_DegreeOfFreedom theEdgeType) const;
//! Create super mesh and run triangulation procedure.
void perform (Bnd_Box2d& theBndBox,
BRepMesh::Array1OfInteger& theVertexIndices);
//! Run triangulation procedure.
void perform (BRepMesh::Array1OfInteger& theVertexIndices,
const Standard_Integer theCellsCountU = -1,
const Standard_Integer theCellsCountV = -1);
//! Build the super mesh.
void superMesh (const Bnd_Box2d& theBox);
void superMesh (const Bnd_Box2d& theBox,
const Standard_Integer theCellsCountU,
const Standard_Integer theCellsCountV);
//! Computes the triangulation and adds the vertices,
//! edges and triangles to the Mesh data structure.

180
src/BRepMesh/BRepMesh_FastDiscretFace.cxx
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@ -23,6 +23,7 @@
#include <BRepAdaptor_HSurface.hxx>
#include <BRepAdaptor_Curve.hxx>
#include <Adaptor3d_IsoCurve.hxx>
#include <Adaptor3d_HCurve.hxx>
#include <BRep_ListIteratorOfListOfPointRepresentation.hxx>
#include <BRep_PointRepresentation.hxx>
@ -162,6 +163,119 @@ namespace
private:
const TopoDS_Vertex& myVertex;
};
void ComputeErrFactors (const Standard_Real theDeflection,
const Handle(Adaptor3d_HSurface)& theFace,
Standard_Real& theErrFactorU,
Standard_Real& theErrFactorV)
{
theErrFactorU = theDeflection * 10.;
theErrFactorV = theDeflection * 10.;
switch (theFace->GetType ())
{
case GeomAbs_Cylinder:
case GeomAbs_Cone:
case GeomAbs_Sphere:
case GeomAbs_Torus:
break;
case GeomAbs_SurfaceOfExtrusion:
case GeomAbs_SurfaceOfRevolution:
{
Handle (Adaptor3d_HCurve) aCurve = theFace->BasisCurve ();
if (aCurve->GetType () == GeomAbs_BSplineCurve && aCurve->Degree () > 2)
{
theErrFactorV /= (aCurve->Degree () * aCurve->NbKnots ());
}
break;
}
case GeomAbs_BezierSurface:
{
if (theFace->UDegree () > 2)
{
theErrFactorU /= (theFace->UDegree ());
}
if (theFace->VDegree () > 2)
{
theErrFactorV /= (theFace->VDegree ());
}
break;
}
case GeomAbs_BSplineSurface:
{
if (theFace->UDegree () > 2)
{
theErrFactorU /= (theFace->UDegree () * theFace->NbUKnots ());
}
if (theFace->VDegree () > 2)
{
theErrFactorV /= (theFace->VDegree () * theFace->NbVKnots ());
}
break;
}
case GeomAbs_Plane:
default:
theErrFactorU = theErrFactorV = 1.;
}
}
void AdjustCellsCounts (const Handle(Adaptor3d_HSurface)& theFace,
const Standard_Integer theNbVertices,
Standard_Integer& theCellsCountU,
Standard_Integer& theCellsCountV)
{
const GeomAbs_SurfaceType aType = theFace->GetType ();
if (aType == GeomAbs_OtherSurface)
{
// fallback to the default behavior
theCellsCountU = theCellsCountV = -1;
return;
}
Standard_Real aSqNbVert = theNbVertices;
if (aType == GeomAbs_Plane)
{
theCellsCountU = theCellsCountV = (Standard_Integer)Ceiling (Pow (2, Log10 (aSqNbVert)));
}
else if (aType == GeomAbs_Cylinder || aType == GeomAbs_Cone)
{
theCellsCountV = (Standard_Integer)Ceiling (Pow (2, Log10 (aSqNbVert)));
}
else if (aType == GeomAbs_SurfaceOfExtrusion || aType == GeomAbs_SurfaceOfRevolution)
{
Handle (Adaptor3d_HCurve) aCurve = theFace->BasisCurve ();
if (aCurve->GetType () == GeomAbs_Line ||
(aCurve->GetType () == GeomAbs_BSplineCurve && aCurve->Degree () < 2))
{
// planar, cylindrical, conical cases
if (aType == GeomAbs_SurfaceOfExtrusion)
theCellsCountU = (Standard_Integer)Ceiling (Pow (2, Log10 (aSqNbVert)));
else
theCellsCountV = (Standard_Integer)Ceiling (Pow (2, Log10 (aSqNbVert)));
}
if (aType == GeomAbs_SurfaceOfExtrusion)
{
// V is always a line
theCellsCountV = (Standard_Integer)Ceiling (Pow (2, Log10 (aSqNbVert)));
}
}
else if (aType == GeomAbs_BezierSurface || aType == GeomAbs_BSplineSurface)
{
if (theFace->UDegree () < 2)
{
theCellsCountU = (Standard_Integer)Ceiling (Pow (2, Log10 (aSqNbVert)));
}
if (theFace->VDegree () < 2)
{
theCellsCountV = (Standard_Integer)Ceiling (Pow (2, Log10 (aSqNbVert)));
}
}
theCellsCountU = Max (theCellsCountU, 2);
theCellsCountV = Max (theCellsCountV, 2);
}
}
@ -359,7 +473,56 @@ void BRepMesh_FastDiscretFace::add(const Handle(BRepMesh_FaceAttribute)& theAttr
for ( Standard_Integer i = 1; i <= nbVertices; ++i )
tabvert_corr(i) = i;
BRepMesh_Delaun trigu(myStructure, tabvert_corr);
Handle (Adaptor3d_HSurface) aSurface (myAttribute->Surface ());
GeomAbs_SurfaceType aType = aSurface->GetType ();
while (aType == GeomAbs_OffsetSurface)
{
aSurface = aSurface->BasisSurface ();
aType = aSurface->GetType ();
}
// For better meshing performance we try to estimate the acceleration circles grid structure sizes:
// For each parametric direction (U, V) we estimate firstly an approximate distance between the future points -
// this estimation takes into account the required face deflection and the complexity of the face.
// Particularly, the complexity of the faces based on BSpline curves and surfaces requires much more points.
// At the same time, for planar faces and linear parts of the arbitrary surfaces usually no intermediate points
// are necessary.
// The general idea for each parametric direction:
// cells_count = 2 ^ log10 ( estimated_points_count )
// For linear parametric direction we fall back to the initial vertex count:
// cells_count = 2 ^ log10 ( initial_vertex_count )
Standard_Real anErrFactorU, anErrFactorV;
ComputeErrFactors(myAttribute->GetDefFace (), aSurface, anErrFactorU, anErrFactorV);
Standard_Integer aCellsCountU, aCellsCountV;
if (aType == GeomAbs_Torus)
{
aCellsCountU = (Standard_Integer)Ceiling(Pow(2, Log10(
(myAttribute->GetUMax() - myAttribute->GetUMin()) / myAttribute->GetDeltaX())));
aCellsCountV = (Standard_Integer)Ceiling(Pow(2, Log10(
(myAttribute->GetVMax() - myAttribute->GetVMin()) / myAttribute->GetDeltaY())));
}
else if (aType == GeomAbs_Cylinder)
{
aCellsCountU = (Standard_Integer)Ceiling(Pow(2, Log10(
(myAttribute->GetUMax() - myAttribute->GetUMin()) / myAttribute->GetDeltaX() /
(myAttribute->GetVMax() - myAttribute->GetVMin()))));
aCellsCountV = (Standard_Integer)Ceiling(Pow(2, Log10(
(myAttribute->GetVMax() - myAttribute->GetVMin()) / anErrFactorV)));
}
else
{
aCellsCountU = (Standard_Integer)Ceiling(Pow(2, Log10(
(myAttribute->GetUMax() - myAttribute->GetUMin()) / myAttribute->GetDeltaX() / anErrFactorU)));
aCellsCountV = (Standard_Integer)Ceiling(Pow(2, Log10(
(myAttribute->GetVMax() - myAttribute->GetVMin()) / myAttribute->GetDeltaY() / anErrFactorV)));
}
AdjustCellsCounts(aSurface, nbVertices, aCellsCountU, aCellsCountV);
BRepMesh_Delaun trigu(myStructure, tabvert_corr, aCellsCountU, aCellsCountV);
//removed all free edges from triangulation
const Standard_Integer nbLinks = myStructure->NbLinks();
@ -376,16 +539,13 @@ void BRepMesh_FastDiscretFace::add(const Handle(BRepMesh_FaceAttribute)& theAttr
}
}
const Handle(BRepAdaptor_HSurface)& gFace = myAttribute->Surface();
GeomAbs_SurfaceType thetype = gFace->GetType();
Standard_Boolean rajout =
(thetype == GeomAbs_Sphere || thetype == GeomAbs_Torus);
(aType == GeomAbs_Sphere || aType == GeomAbs_Torus);
// Check the necessity to fill the map of parameters
const Standard_Boolean useUVParam = (thetype == GeomAbs_Torus ||
thetype == GeomAbs_BezierSurface ||
thetype == GeomAbs_BSplineSurface);
const Standard_Boolean useUVParam = (aType == GeomAbs_Torus ||
aType == GeomAbs_BezierSurface ||
aType == GeomAbs_BSplineSurface);
const Standard_Real umax = myAttribute->GetUMax();
const Standard_Real umin = myAttribute->GetUMin();
@ -405,12 +565,12 @@ void BRepMesh_FastDiscretFace::add(const Handle(BRepMesh_FaceAttribute)& theAttr
aDef = control(trigu, Standard_True);
rajout = (aDef > myAttribute->GetDefFace() || aDef < 0.);
}
if (thetype != GeomAbs_Plane)
if (aType != GeomAbs_Plane)
{
if (!rajout && useUVParam)
{
rajout = (myVParam.Extent() > 2 &&
(gFace->IsUClosed() || gFace->IsVClosed()));
(aSurface->IsUClosed() || aSurface->IsVClosed()));
}
if (rajout)

12
tests/bugs/mesh/bug26889
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@ -1,5 +1,3 @@
puts "TODO CR26889 ALL: Error: the mesh takes too long to be built"
puts "========="
puts "CR26889"
puts "========="
@ -19,16 +17,6 @@ dchrono t restart
incmesh a_1 0.1 1
dchrono t stop counter incmesh
set info [dlog get]
dlog reset
dlog off
regexp {COUNTER incmesh: +([-0-9.+eE]+)} ${info} full Time
if { ${Time} > 30. } {
puts "Error: the mesh takes too long to be built"
}
checktrinfo a_1 -tri -nod
vinit

15
tests/bugs/mesh/bug29715 Normal file
View File

@ -0,0 +1,15 @@
puts "======="
puts "0029715: Mesh - Estimate the grid size of the acceleration structure by the complexity of the face"
puts "======="
puts ""
if {[info commands stepread] == ""} {pload XSDRAW}
stepread [locate_data_file bug29715_slow.stp] a *
renamevar a_1 a
chrono h reset start
incmesh a 0.0027
chrono h stop show COUNTER Meshing
tricheck a