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Issue 0020947: EDF 1467 SMESH: Modify the formula to calculate Aspect Ratio on quadrangles

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ouv 2010-10-13 09:49:12 +00:00
parent 25b69822a1
commit f0f625f609
3 changed files with 86 additions and 40 deletions
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8
doc/salome/gui/SMESH/input/aspect_ratio.doc
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@ -13,10 +13,10 @@ nodes is calculated by the formula:
\image html formula4.png
- The <b>Aspect Ratio</b> of a \b quadrangle 2D element consisting of
4 nodes is the worst (i.e. the greatest) value from all triangles
which can be built taking three nodes of the quadrangle. There are
four triangles to consider:
- The <b>Aspect Ratio</b> of a \b quadrangle 2D element consisting of 4
nodes is calculated by the formula:
\image html formula5.png
\image html image138.gif

118
src/Controls/SMESH_Controls.cxx
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@ -465,46 +465,92 @@ double AspectRatio::GetValue( const TSequenceOfXYZ& P )
return alfa * maxLen * half_perimeter / anArea;
}
else if( nbNodes == 4 ) { // quadrangle
// return aspect ratio of the worst triange which can be built
// Compute lengths of the sides
std::vector< double > aLen (4);
aLen[0] = getDistance( P(1), P(2) );
aLen[1] = getDistance( P(2), P(3) );
aLen[2] = getDistance( P(3), P(4) );
aLen[3] = getDistance( P(4), P(1) );
// Compute lengths of the diagonals
std::vector< double > aDia (2);
aDia[0] = getDistance( P(1), P(3) );
aDia[1] = getDistance( P(2), P(4) );
// Compute areas of all triangles which can be built
// taking three nodes of the quadrangle
TSequenceOfXYZ triaPnts(3);
// triangle on nodes 1 3 2
triaPnts(1) = P(1);
triaPnts(2) = P(3);
triaPnts(3) = P(2);
double ar = GetValue( triaPnts );
// triangle on nodes 1 3 4
triaPnts(3) = P(4);
ar = Max ( ar, GetValue( triaPnts ));
// triangle on nodes 1 2 4
triaPnts(2) = P(2);
ar = Max ( ar, GetValue( triaPnts ));
// triangle on nodes 3 2 4
triaPnts(1) = P(3);
ar = Max ( ar, GetValue( triaPnts ));
return ar;
std::vector< double > anArea (4);
anArea[0] = getArea( P(1), P(2), P(3) );
anArea[1] = getArea( P(1), P(2), P(4) );
anArea[2] = getArea( P(1), P(3), P(4) );
anArea[3] = getArea( P(2), P(3), P(4) );
// Q = alpha * L * C1 / C2, where
//
// alpha = sqrt( 1/32 )
// L = max( L1, L2, L3, L4, D1, D2 )
// C1 = sqrt( ( L1^2 + L1^2 + L1^2 + L1^2 ) / 4 )
// C2 = min( S1, S2, S3, S4 )
// Li - lengths of the edges
// Di - lengths of the diagonals
// Si - areas of the triangles
const double alpha = sqrt( 1 / 32. );
double L = Max( aLen[ 0 ],
Max( aLen[ 1 ],
Max( aLen[ 2 ],
Max( aLen[ 3 ],
Max( aDia[ 0 ], aDia[ 1 ] ) ) ) ) );
double C1 = sqrt( ( aLen[0] * aLen[0] +
aLen[1] * aLen[1] +
aLen[2] * aLen[2] +
aLen[3] * aLen[3] ) / 4. );
double C2 = Min( anArea[ 0 ],
Min( anArea[ 1 ],
Min( anArea[ 2 ], anArea[ 3 ] ) ) );
if ( C2 <= Precision::Confusion() )
return 0.;
return alpha * L * C1 / C2;
}
else if( nbNodes == 8 ){ // nbNodes==8 - quadratic quadrangle
// return aspect ratio of the worst triange which can be built
// Compute lengths of the sides
std::vector< double > aLen (4);
aLen[0] = getDistance( P(1), P(3) );
aLen[1] = getDistance( P(3), P(5) );
aLen[2] = getDistance( P(5), P(7) );
aLen[3] = getDistance( P(7), P(1) );
// Compute lengths of the diagonals
std::vector< double > aDia (2);
aDia[0] = getDistance( P(1), P(5) );
aDia[1] = getDistance( P(3), P(7) );
// Compute areas of all triangles which can be built
// taking three nodes of the quadrangle
TSequenceOfXYZ triaPnts(3);
// triangle on nodes 1 3 2
triaPnts(1) = P(1);
triaPnts(2) = P(5);
triaPnts(3) = P(3);
double ar = GetValue( triaPnts );
// triangle on nodes 1 3 4
triaPnts(3) = P(7);
ar = Max ( ar, GetValue( triaPnts ));
// triangle on nodes 1 2 4
triaPnts(2) = P(3);
ar = Max ( ar, GetValue( triaPnts ));
// triangle on nodes 3 2 4
triaPnts(1) = P(5);
ar = Max ( ar, GetValue( triaPnts ));
return ar;
std::vector< double > anArea (4);
anArea[0] = getArea( P(1), P(3), P(5) );
anArea[1] = getArea( P(1), P(3), P(7) );
anArea[2] = getArea( P(1), P(5), P(7) );
anArea[3] = getArea( P(3), P(5), P(7) );
// Q = alpha * L * C1 / C2, where
//
// alpha = sqrt( 1/32 )
// L = max( L1, L2, L3, L4, D1, D2 )
// C1 = sqrt( ( L1^2 + L1^2 + L1^2 + L1^2 ) / 4 )
// C2 = min( S1, S2, S3, S4 )
// Li - lengths of the edges
// Di - lengths of the diagonals
// Si - areas of the triangles
const double alpha = sqrt( 1 / 32. );
double L = Max( aLen[ 0 ],
Max( aLen[ 1 ],
Max( aLen[ 2 ],
Max( aLen[ 3 ],
Max( aDia[ 0 ], aDia[ 1 ] ) ) ) ) );
double C1 = sqrt( ( aLen[0] * aLen[0] +
aLen[1] * aLen[1] +
aLen[2] * aLen[2] +
aLen[3] * aLen[3] ) / 4. );
double C2 = Min( anArea[ 0 ],
Min( anArea[ 1 ],
Min( anArea[ 2 ], anArea[ 3 ] ) ) );
if ( C2 <= Precision::Confusion() )
return 0.;
return alpha * L * C1 / C2;
}
return 0;
}