From: eap Date: Mon, 12 Dec 2005 11:19:33 +0000 (+0000) Subject: PAL10872. Fix 2D aspect ratio according to Nardir Bouhamou's specification X-Git-Tag: T_3_1_0pre~10 X-Git-Url: http://git.salome-platform.org/gitweb/?a=commitdiff_plain;h=8a9307decf3e973c08fdf0247b6e03ecfcc35259;p=modules%2Fsmesh.git PAL10872. Fix 2D aspect ratio according to Nardir Bouhamou's specification --- diff --git a/src/Controls/SMESH_Controls.cxx b/src/Controls/SMESH_Controls.cxx index 3ebd18b90..7e6603b61 100644 --- a/src/Controls/SMESH_Controls.cxx +++ b/src/Controls/SMESH_Controls.cxx @@ -282,6 +282,10 @@ SMDSAbs_ElementType MinimumAngle::GetType() const */ double AspectRatio::GetValue( const TSequenceOfXYZ& P ) { + // According to "Mesh quality control" by Nadir Bouhamau referring to + // Pascal Jean Frey and Paul-Louis George. Maillages, applications aux elements finis. + // Hermes Science publications, Paris 1999 ISBN 2-7462-0024-4 + int nbNodes = P.size(); if ( nbNodes < 3 ) @@ -289,12 +293,7 @@ double AspectRatio::GetValue( const TSequenceOfXYZ& P ) // Compute lengths of the sides - //double aLen[ nbNodes ]; -#ifndef WNT - double aLen [nbNodes]; -#else - double* aLen = (double *)new double[nbNodes]; -#endif + vector< double > aLen (nbNodes); for ( int i = 0; i < nbNodes - 1; i++ ) aLen[ i ] = getDistance( P( i + 1 ), P( i + 2 ) ); @@ -304,30 +303,43 @@ double AspectRatio::GetValue( const TSequenceOfXYZ& P ) if ( nbNodes == 3 ) { + // Q = alfa * h * p / S, where + // + // alfa = sqrt( 3 ) / 6 + // h - length of the longest edge + // p - half perimeter + // S - triangle surface + + const double alfa = sqrt( 3. ) / 6.; + double maxLen = Max( aLen[ 0 ], Max( aLen[ 1 ], aLen[ 2 ] ) ); + double half_perimeter = ( aLen[0] + aLen[1] + aLen[2] ) / 2.; double anArea = getArea( P( 1 ), P( 2 ), P( 3 ) ); if ( anArea <= Precision::Confusion() ) return 0.; - double aMaxLen = Max( aLen[ 0 ], Max( aLen[ 1 ], aLen[ 2 ] ) ); - static double aCoef = sqrt( 3. ) / 4; - return aCoef * aMaxLen * aMaxLen / anArea; + return alfa * maxLen * half_perimeter / anArea; } else { - double aMinLen = aLen[ 0 ]; - double aMaxLen = aLen[ 0 ]; - - for(int i = 1; i < nbNodes ; i++ ){ - aMinLen = Min( aMinLen, aLen[ i ] ); - aMaxLen = Max( aMaxLen, aLen[ i ] ); - } -#ifdef WNT - delete [] aLen; -#endif - if ( aMinLen <= Precision::Confusion() ) - return 0.; - - return aMaxLen / aMinLen; + // return aspect ratio of the worst triange 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; } } @@ -447,7 +459,7 @@ double AspectRatio3D::GetValue( const TSequenceOfXYZ& P ) double aVolume = getVolume(P); //double aVolume = getVolume(aLen); double aHeight = getMaxHeight(aLen); - static double aCoeff = sqrt(6.0)/36.0; + static double aCoeff = sqrt(2.0)/12.0; aQuality = aCoeff*aHeight*aSumArea/aVolume; break; }