Files
create/src/Mod/Mesh/App/WildMagic4/Wm4ImplicitSurface.cpp
2011-10-10 13:44:52 +00:00

219 lines
7.3 KiB
C++

// Wild Magic Source Code
// David Eberly
// http://www.geometrictools.com
// Copyright (c) 1998-2007
//
// This library is free software; you can redistribute it and/or modify it
// under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation; either version 2.1 of the License, or (at
// your option) any later version. The license is available for reading at
// either of the locations:
// http://www.gnu.org/copyleft/lgpl.html
// http://www.geometrictools.com/License/WildMagicLicense.pdf
// The license applies to versions 0 through 4 of Wild Magic.
//
// Version: 4.0.1 (2006/07/23)
#include "Wm4FoundationPCH.h"
#include "Wm4ImplicitSurface.h"
namespace Wm4
{
//----------------------------------------------------------------------------
template <class Real>
ImplicitSurface<Real>::ImplicitSurface ()
{
}
//----------------------------------------------------------------------------
template <class Real>
ImplicitSurface<Real>::~ImplicitSurface ()
{
}
//----------------------------------------------------------------------------
template <class Real>
bool ImplicitSurface<Real>::IsOnSurface (const Vector3<Real>& rkP,
Real fEpsilon) const
{
return Math<Real>::FAbs(F(rkP)) <= fEpsilon;
}
//----------------------------------------------------------------------------
template <class Real>
Vector3<Real> ImplicitSurface<Real>::GetGradient (const Vector3<Real>& rkP)
const
{
Real fFX = FX(rkP);
Real fFY = FY(rkP);
Real fFZ = FZ(rkP);
return Vector3<Real>(fFX,fFY,fFZ);
}
//----------------------------------------------------------------------------
template <class Real>
Matrix3<Real> ImplicitSurface<Real>::GetHessian (const Vector3<Real>& rkP)
const
{
Real fFXX = FXX(rkP);
Real fFXY = FXY(rkP);
Real fFXZ = FXZ(rkP);
Real fFYY = FYY(rkP);
Real fFYZ = FYZ(rkP);
Real fFZZ = FZZ(rkP);
return Matrix3<Real>(fFXX,fFXY,fFXZ,fFXY,fFYY,fFYZ,fFXZ,fFYZ,fFZZ);
}
//----------------------------------------------------------------------------
template <class Real>
void ImplicitSurface<Real>::GetFrame (const Vector3<Real>& rkP,
Vector3<Real>& rkTangent0, Vector3<Real>& rkTangent1,
Vector3<Real>& rkNormal) const
{
rkNormal = GetGradient(rkP);
Vector3<Real>::GenerateOrthonormalBasis(rkTangent0,rkTangent1,rkNormal);
}
//----------------------------------------------------------------------------
template <class Real>
bool ImplicitSurface<Real>::ComputePrincipalCurvatureInfo (
const Vector3<Real>& rkP, Real& rfCurv0, Real& rfCurv1,
Vector3<Real>& rkDir0, Vector3<Real>& rkDir1)
{
// Principal curvatures and directions for implicitly defined surfaces
// F(x,y,z) = 0.
//
// DF = (Fx,Fy,Fz), L = Length(DF)
//
// D^2 F = +- -+
// | Fxx Fxy Fxz |
// | Fxy Fyy Fyz |
// | Fxz Fyz Fzz |
// +- -+
//
// adj(D^2 F) = +- -+
// | Fyy*Fzz-Fyz*Fyz Fyz*Fxz-Fxy*Fzz Fxy*Fyz-Fxz*Fyy |
// | Fyz*Fxz-Fxy*Fzz Fxx*Fzz-Fxz*Fxz Fxy*Fxz-Fxx*Fyz |
// | Fxy*Fyz-Fxz*Fyy Fxy*Fxz-Fxx*Fyz Fxx*Fyy-Fxy*Fxy |
// +- -+
//
// Gaussian curvature = [DF^t adj(D^2 F) DF]/L^4
//
// Mean curvature = 0.5*[trace(D^2 F)/L - (DF^t D^2 F DF)/L^3]
// first derivatives
Real fFX = FX(rkP);
Real fFY = FY(rkP);
Real fFZ = FZ(rkP);
Real fL = Math<Real>::Sqrt(fFX*fFX + fFY*fFY + fFZ*fFZ);
if (fL <= Math<Real>::ZERO_TOLERANCE)
{
return false;
}
Real fFXFX = fFX*fFX;
Real fFXFY = fFX*fFY;
Real fFXFZ = fFX*fFZ;
Real fFYFY = fFY*fFY;
Real fFYFZ = fFY*fFZ;
Real fFZFZ = fFZ*fFZ;
Real fInvL = ((Real)1.0)/fL;
Real fInvL2 = fInvL*fInvL;
Real fInvL3 = fInvL*fInvL2;
Real fInvL4 = fInvL2*fInvL2;
// second derivatives
Real fFXX = FXX(rkP);
Real fFXY = FXY(rkP);
Real fFXZ = FXZ(rkP);
Real fFYY = FYY(rkP);
Real fFYZ = FYZ(rkP);
Real fFZZ = FZZ(rkP);
// mean curvature
Real fMCurv = ((Real)0.5)*fInvL3*(fFXX*(fFYFY+fFZFZ) + fFYY*(fFXFX+fFZFZ)
+ fFZZ*(fFXFX+fFYFY)
- ((Real)2.0)*(fFXY*fFXFY+fFXZ*fFXFZ+fFYZ*fFYFZ));
// Gaussian curvature
Real fGCurv = fInvL4*(fFXFX*(fFYY*fFZZ-fFYZ*fFYZ)
+ fFYFY*(fFXX*fFZZ-fFXZ*fFXZ) + fFZFZ*(fFXX*fFYY-fFXY*fFXY)
+ ((Real)2.0)*(fFXFY*(fFXZ*fFYZ-fFXY*fFZZ)
+ fFXFZ*(fFXY*fFYZ-fFXZ*fFYY)
+ fFYFZ*(fFXY*fFXZ-fFXX*fFYZ)));
// solve for principal curvatures
Real fDiscr = Math<Real>::Sqrt(Math<Real>::FAbs(fMCurv*fMCurv-fGCurv));
rfCurv0 = fMCurv - fDiscr;
rfCurv1 = fMCurv + fDiscr;
Real fM00 = ((-(Real)1.0 + fFXFX*fInvL2)*fFXX)*fInvL + (fFXFY*fFXY)*fInvL3
+ (fFXFZ*fFXZ)*fInvL3;
Real fM01 = ((-(Real)1.0 + fFXFX*fInvL2)*fFXY)*fInvL + (fFXFY*fFYY)*fInvL3
+ (fFXFZ*fFYZ)*fInvL3;
Real fM02 = ((-(Real)1.0 + fFXFX*fInvL2)*fFXZ)*fInvL + (fFXFY*fFYZ)*fInvL3
+ (fFXFZ*fFZZ)*fInvL3;
Real fM10 = (fFXFY*fFXX)*fInvL3 + ((-(Real)1.0 + fFYFY*fInvL2)*fFXY)*fInvL
+ (fFYFZ*fFXZ)*fInvL3;
Real fM11 = (fFXFY*fFXY)*fInvL3 + ((-(Real)1.0 + fFYFY*fInvL2)*fFYY)*fInvL
+ (fFYFZ*fFYZ)*fInvL3;
Real fM12 = (fFXFY*fFXZ)*fInvL3 + ((-(Real)1.0 + fFYFY*fInvL2)*fFYZ)*fInvL
+ (fFYFZ*fFZZ)*fInvL3;
Real fM20 = (fFXFZ*fFXX)*fInvL3 + (fFYFZ*fFXY)*fInvL3 + ((-(Real)1.0
+ fFZFZ*fInvL2)*fFXZ)*fInvL;
Real fM21 = (fFXFZ*fFXY)*fInvL3 + (fFYFZ*fFYY)*fInvL3 + ((-(Real)1.0
+ fFZFZ*fInvL2)*fFYZ)*fInvL;
Real fM22 = (fFXFZ*fFXZ)*fInvL3 + (fFYFZ*fFYZ)*fInvL3 + ((-(Real)1.0
+ fFZFZ*fInvL2)*fFZZ)*fInvL;
// solve for principal directions
Real fTmp1 = fM00 + rfCurv0;
Real fTmp2 = fM11 + rfCurv0;
Real fTmp3 = fM22 + rfCurv0;
Vector3<Real> akU[3];
Real afLength[3];
akU[0].X() = fM01*fM12-fM02*fTmp2;
akU[0].Y() = fM02*fM10-fM12*fTmp1;
akU[0].Z() = fTmp1*fTmp2-fM01*fM10;
afLength[0] = akU[0].Length();
akU[1].X() = fM01*fTmp3-fM02*fM21;
akU[1].Y() = fM02*fM20-fTmp1*fTmp3;
akU[1].Z() = fTmp1*fM21-fM01*fM20;
afLength[1] = akU[1].Length();
akU[2].X() = fTmp2*fTmp3-fM12*fM21;
akU[2].Y() = fM12*fM20-fM10*fTmp3;
akU[2].Z() = fM10*fM21-fM20*fTmp2;
afLength[2] = akU[2].Length();
int iMaxIndex = 0;
Real fMax = afLength[0];
if (afLength[1] > fMax)
{
iMaxIndex = 1;
fMax = afLength[1];
}
if (afLength[2] > fMax)
{
iMaxIndex = 2;
}
Real fInvLength = ((Real)1.0)/afLength[iMaxIndex];
akU[iMaxIndex] *= fInvLength;
rkDir1 = akU[iMaxIndex];
rkDir0 = rkDir1.UnitCross(Vector3<Real>(fFX,fFY,fFZ));
return true;
}
//----------------------------------------------------------------------------
//----------------------------------------------------------------------------
// explicit instantiation
//----------------------------------------------------------------------------
template WM4_FOUNDATION_ITEM
class ImplicitSurface<float>;
template WM4_FOUNDATION_ITEM
class ImplicitSurface<double>;
//----------------------------------------------------------------------------
}