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Added Mean Ratio metric for triangle quality.

This commit is contained in:
Federico Ponchio 2007-11-26 14:11:38 +00:00
parent da56c33f36
commit 700ab9112d
1 changed files with 24 additions and 3 deletions
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27
vcg/space/triangle3.h
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@ -24,6 +24,9 @@
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$Log: not supported by cvs2svn $ $Log: not supported by cvs2svn $
Revision 1.19 2007/11/19 17:04:05 ponchio
QualityRadii values fixed.
Revision 1.18 2007/11/18 19:12:54 ponchio Revision 1.18 2007/11/18 19:12:54 ponchio
Typo (missing comma). Typo (missing comma).
@ -276,8 +279,8 @@ P3ScalarType Quality( Point3<P3ScalarType> const &p0, Point3<P3ScalarType> const
/// Compute a shape quality measure of the triangle composed by points p0,p1,p2 /// Compute a shape quality measure of the triangle composed by points p0,p1,p2
/// It Returns inradius/circumradius /// It Returns inradius/circumradius
/// the range is range [0, 0.5] /// the range is range [0, 1]
/// e.g. Equilateral triangle 0.5, halfsquare: 0.41, ... up to a line that has zero quality. /// e.g. Equilateral triangle 1, halfsquare: 0.81, ... up to a line that has zero quality.
template<class P3ScalarType> template<class P3ScalarType>
P3ScalarType QualityRadii(Point3<P3ScalarType> const &p0, P3ScalarType QualityRadii(Point3<P3ScalarType> const &p0,
Point3<P3ScalarType> const &p1, Point3<P3ScalarType> const &p1,
@ -292,7 +295,25 @@ P3ScalarType QualityRadii(Point3<P3ScalarType> const &p0,
if(area2 <= 0) return 0; if(area2 <= 0) return 0;
//circumradius: (a*b*c)/(4*sqrt(area2)) //circumradius: (a*b*c)/(4*sqrt(area2))
//inradius: (a*b*c)/(4*circumradius*sum) => sqrt(area2)/sum; //inradius: (a*b*c)/(4*circumradius*sum) => sqrt(area2)/sum;
return (4*area2)/(a*b*c*sum); return (8*area2)/(a*b*c*sum);
}
/// Compute a shape quality measure of the triangle composed by points p0,p1,p2
/// It Returns mean ratio 2sqrt(a, b)/(a+b) where a+b are the eigenvalues of the M^tM of the
/// transformation matrix into a regular simplex
/// the range is range [0, 1]
template<class P3ScalarType>
P3ScalarType QualityMeanRatio(Point3<P3ScalarType> const &p0,
Point3<P3ScalarType> const &p1,
Point3<P3ScalarType> const &p2) {
P3ScalarType a=(p1-p0).Norm();
P3ScalarType b=(p2-p0).Norm();
P3ScalarType c=(p1-p2).Norm();
P3ScalarType sum = (a + b + c)*0.5; //semiperimeter
P3ScalarType area2 = sum*(a+b-sum)*(a+c-sum)*(b+c-sum);
if(area2 <= 0) return 0;
return (4*sqrt(3)*sqrt(area2))/(a*a + b*b + c*c);
} }
/// Returns the normal to the plane passing through p0,p1,p2 /// Returns the normal to the plane passing through p0,p1,p2