Gabriele Cosmo
816 lines
25 KiB
C++
816 lines
25 KiB
C++
//
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// ********************************************************************
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// * License and Disclaimer *
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// * *
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// * The Geant4 software is copyright of the Copyright Holders of *
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// * the Geant4 Collaboration. It is provided under the terms and *
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// * conditions of the Geant4 Software License, included in the file *
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// * LICENSE and available at http://cern.ch/geant4/license . These *
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// * include a list of copyright holders. *
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// * *
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// * Neither the authors of this software system, nor their employing *
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// * institutes,nor the agencies providing financial support for this *
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// * work make any representation or warranty, express or implied, *
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// * regarding this software system or assume any liability for its *
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// * use. Please see the license in the file LICENSE and URL above *
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// * for the full disclaimer and the limitation of liability. *
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// * *
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// * This code implementation is the result of the scientific and *
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// * technical work of the GEANT4 collaboration. *
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// * By using, copying, modifying or distributing the software (or *
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// * any work based on the software) you agree to acknowledge its *
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// * use in resulting scientific publications, and indicate your *
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// * acceptance of all terms of the Geant4 Software license. *
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// ********************************************************************
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//
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// G4TriangularFacet implementation
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//
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// 31.10.2004, P R Truscott, QinetiQ Ltd, UK - Created.
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// 01.08.2007, P R Truscott, QinetiQ Ltd, UK
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// Significant modification to correct for errors and enhance
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// based on patches/observations kindly provided by Rickard
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// Holmberg.
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// 12.10.2012, M Gayer, CERN
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// New implementation reducing memory requirements by 50%,
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// and considerable CPU speedup together with the new
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// implementation of G4TessellatedSolid.
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// 23.02.2016, E Tcherniaev, CERN
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// Improved test to detect degenerate (too small or
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// too narrow) triangles.
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// --------------------------------------------------------------------
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#include "G4TriangularFacet.hh"
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#include "Randomize.hh"
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#include "G4TessellatedGeometryAlgorithms.hh"
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using namespace std;
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///////////////////////////////////////////////////////////////////////////////
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//
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// Definition of triangular facet using absolute vectors to fVertices.
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// From this for first vector is retained to define the facet location and
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// two relative vectors (E0 and E1) define the sides and orientation of
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// the outward surface normal.
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//
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G4TriangularFacet::G4TriangularFacet (const G4ThreeVector& vt0,
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const G4ThreeVector& vt1,
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const G4ThreeVector& vt2,
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G4FacetVertexType vertexType)
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{
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fVertices = new vector<G4ThreeVector>(3);
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SetVertex(0, vt0);
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if (vertexType == ABSOLUTE)
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{
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SetVertex(1, vt1);
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SetVertex(2, vt2);
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fE1 = vt1 - vt0;
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fE2 = vt2 - vt0;
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}
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else
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{
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SetVertex(1, vt0 + vt1);
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SetVertex(2, vt0 + vt2);
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fE1 = vt1;
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fE2 = vt2;
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}
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G4ThreeVector E1xE2 = fE1.cross(fE2);
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fArea = 0.5 * E1xE2.mag();
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for (G4int i = 0; i < 3; ++i) fIndices[i] = -1;
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fIsDefined = true;
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G4double delta = kCarTolerance; // Set tolerance for checking
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// Check length of edges
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//
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G4double leng1 = fE1.mag();
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G4double leng2 = (fE2-fE1).mag();
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G4double leng3 = fE2.mag();
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if (leng1 <= delta || leng2 <= delta || leng3 <= delta)
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{
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fIsDefined = false;
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}
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// Check min height of triangle
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//
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if (fIsDefined)
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{
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if (2.*fArea/std::max(std::max(leng1,leng2),leng3) <= delta)
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{
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fIsDefined = false;
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}
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}
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// Define facet
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//
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if (!fIsDefined)
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{
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ostringstream message;
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message << "Facet is too small or too narrow." << G4endl
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<< "Triangle area = " << fArea << G4endl
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<< "P0 = " << GetVertex(0) << G4endl
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<< "P1 = " << GetVertex(1) << G4endl
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<< "P2 = " << GetVertex(2) << G4endl
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<< "Side1 length (P0->P1) = " << leng1 << G4endl
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<< "Side2 length (P1->P2) = " << leng2 << G4endl
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<< "Side3 length (P2->P0) = " << leng3;
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G4Exception("G4TriangularFacet::G4TriangularFacet()",
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"GeomSolids1001", JustWarning, message);
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fSurfaceNormal.set(0,0,0);
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fA = fB = fC = 0.0;
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fDet = 0.0;
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fCircumcentre = vt0 + 0.5*fE1 + 0.5*fE2;
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fArea = fRadius = 0.0;
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}
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else
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{
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fSurfaceNormal = E1xE2.unit();
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fA = fE1.mag2();
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fB = fE1.dot(fE2);
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fC = fE2.mag2();
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fDet = std::fabs(fA*fC - fB*fB);
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fCircumcentre =
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vt0 + (E1xE2.cross(fE1)*fC + fE2.cross(E1xE2)*fA) / (2.*E1xE2.mag2());
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fRadius = (fCircumcentre - vt0).mag();
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}
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}
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///////////////////////////////////////////////////////////////////////////////
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//
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G4TriangularFacet::G4TriangularFacet ()
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{
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fVertices = new vector<G4ThreeVector>(3);
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G4ThreeVector zero(0,0,0);
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SetVertex(0, zero);
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SetVertex(1, zero);
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SetVertex(2, zero);
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for (G4int i = 0; i < 3; ++i) fIndices[i] = -1;
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fIsDefined = false;
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fSurfaceNormal.set(0,0,0);
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fA = fB = fC = 0;
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fE1 = zero;
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fE2 = zero;
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fDet = 0.0;
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fArea = fRadius = 0.0;
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}
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///////////////////////////////////////////////////////////////////////////////
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//
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G4TriangularFacet::~G4TriangularFacet ()
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{
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SetVertices(nullptr);
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}
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///////////////////////////////////////////////////////////////////////////////
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//
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void G4TriangularFacet::CopyFrom (const G4TriangularFacet& rhs)
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{
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auto p = (char *) &rhs;
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copy(p, p + sizeof(*this), (char *)this);
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if (fIndices[0] < 0 && fVertices == nullptr)
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{
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fVertices = new vector<G4ThreeVector>(3);
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for (G4int i = 0; i < 3; ++i) (*fVertices)[i] = (*rhs.fVertices)[i];
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}
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}
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///////////////////////////////////////////////////////////////////////////////
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//
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void G4TriangularFacet::MoveFrom (G4TriangularFacet& rhs)
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{
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fSurfaceNormal = std::move(rhs.fSurfaceNormal);
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fArea = rhs.fArea;
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fCircumcentre = std::move(rhs.fCircumcentre);
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fRadius = rhs.fRadius;
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fIndices = rhs.fIndices;
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fA = rhs.fA; fB = rhs.fB; fC = rhs.fC;
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fDet = rhs.fDet;
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fSqrDist = rhs.fSqrDist;
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fE1 = std::move(rhs.fE1); fE2 = std::move(rhs.fE2);
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fIsDefined = rhs.fIsDefined;
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fVertices = rhs.fVertices;
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rhs.fVertices = nullptr;
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}
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///////////////////////////////////////////////////////////////////////////////
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//
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G4TriangularFacet::G4TriangularFacet (const G4TriangularFacet& rhs)
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: G4VFacet(rhs)
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{
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CopyFrom(rhs);
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}
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///////////////////////////////////////////////////////////////////////////////
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//
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G4TriangularFacet::G4TriangularFacet (G4TriangularFacet&& rhs) noexcept
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: G4VFacet(rhs)
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{
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MoveFrom(rhs);
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}
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///////////////////////////////////////////////////////////////////////////////
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//
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G4TriangularFacet&
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G4TriangularFacet::operator=(const G4TriangularFacet& rhs)
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{
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SetVertices(nullptr);
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if (this != &rhs)
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{
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delete fVertices;
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CopyFrom(rhs);
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}
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return *this;
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}
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///////////////////////////////////////////////////////////////////////////////
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//
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G4TriangularFacet&
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G4TriangularFacet::operator=(G4TriangularFacet&& rhs) noexcept
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{
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SetVertices(nullptr);
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if (this != &rhs)
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{
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delete fVertices;
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MoveFrom(rhs);
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}
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return *this;
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}
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///////////////////////////////////////////////////////////////////////////////
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//
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// GetClone
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//
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// Simple member function to generate fA duplicate of the triangular facet.
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//
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G4VFacet* G4TriangularFacet::GetClone ()
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{
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auto fc = new G4TriangularFacet (GetVertex(0), GetVertex(1),
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GetVertex(2), ABSOLUTE);
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return fc;
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}
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///////////////////////////////////////////////////////////////////////////////
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//
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// GetFlippedFacet
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//
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// Member function to generate an identical facet, but with the normal vector
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// pointing at 180 degrees.
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//
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G4TriangularFacet* G4TriangularFacet::GetFlippedFacet ()
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{
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auto flipped = new G4TriangularFacet (GetVertex(0), GetVertex(1),
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GetVertex(2), ABSOLUTE);
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return flipped;
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}
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///////////////////////////////////////////////////////////////////////////////
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//
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// Distance (G4ThreeVector)
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//
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// Determines the vector between p and the closest point on the facet to p.
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// This is based on the algorithm published in "Geometric Tools for Computer
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// Graphics," Philip J Scheider and David H Eberly, Elsevier Science (USA),
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// 2003. at the time of writing, the algorithm is also available in fA
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// technical note "Distance between point and triangle in 3D," by David Eberly
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// at http://www.geometrictools.com/Documentation/DistancePoint3Triangle3.pdf
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//
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// The by-product is the square-distance fSqrDist, which is retained
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// in case needed by the other "Distance" member functions.
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//
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G4ThreeVector G4TriangularFacet::Distance (const G4ThreeVector& p)
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{
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G4ThreeVector D = GetVertex(0) - p;
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G4double d = fE1.dot(D);
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G4double e = fE2.dot(D);
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G4double f = D.mag2();
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G4double q = fB*e - fC*d;
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G4double t = fB*d - fA*e;
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fSqrDist = 0.;
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if (q+t <= fDet)
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{
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if (q < 0.0)
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{
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if (t < 0.0)
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{
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//
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// We are in region 4.
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//
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if (d < 0.0)
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{
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t = 0.0;
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if (-d >= fA) {q = 1.0; fSqrDist = fA + 2.0*d + f;}
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else {q = -d/fA; fSqrDist = d*q + f;}
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}
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else
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{
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q = 0.0;
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if (e >= 0.0) {t = 0.0; fSqrDist = f;}
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else if (-e >= fC) {t = 1.0; fSqrDist = fC + 2.0*e + f;}
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else {t = -e/fC; fSqrDist = e*t + f;}
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}
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}
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else
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{
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//
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// We are in region 3.
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//
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q = 0.0;
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if (e >= 0.0) {t = 0.0; fSqrDist = f;}
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else if (-e >= fC) {t = 1.0; fSqrDist = fC + 2.0*e + f;}
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else {t = -e/fC; fSqrDist = e*t + f;}
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}
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}
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else if (t < 0.0)
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{
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//
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// We are in region 5.
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//
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t = 0.0;
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if (d >= 0.0) {q = 0.0; fSqrDist = f;}
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else if (-d >= fA) {q = 1.0; fSqrDist = fA + 2.0*d + f;}
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else {q = -d/fA; fSqrDist = d*q + f;}
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}
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else
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{
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//
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// We are in region 0.
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//
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G4double dist = fSurfaceNormal.dot(D);
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fSqrDist = dist*dist;
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return fSurfaceNormal*dist;
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}
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}
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else
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{
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if (q < 0.0)
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{
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//
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// We are in region 2.
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//
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G4double tmp0 = fB + d;
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G4double tmp1 = fC + e;
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if (tmp1 > tmp0)
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{
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G4double numer = tmp1 - tmp0;
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G4double denom = fA - 2.0*fB + fC;
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if (numer >= denom) {q = 1.0; t = 0.0; fSqrDist = fA + 2.0*d + f;}
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else
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{
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q = numer/denom;
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t = 1.0 - q;
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fSqrDist = q*(fA*q + fB*t +2.0*d) + t*(fB*q + fC*t + 2.0*e) + f;
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}
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}
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else
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{
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q = 0.0;
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if (tmp1 <= 0.0) {t = 1.0; fSqrDist = fC + 2.0*e + f;}
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else if (e >= 0.0) {t = 0.0; fSqrDist = f;}
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else {t = -e/fC; fSqrDist = e*t + f;}
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}
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}
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else if (t < 0.0)
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{
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//
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// We are in region 6.
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//
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G4double tmp0 = fB + e;
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G4double tmp1 = fA + d;
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if (tmp1 > tmp0)
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{
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G4double numer = tmp1 - tmp0;
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G4double denom = fA - 2.0*fB + fC;
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if (numer >= denom) {t = 1.0; q = 0.0; fSqrDist = fC + 2.0*e + f;}
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else
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{
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t = numer/denom;
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q = 1.0 - t;
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fSqrDist = q*(fA*q + fB*t +2.0*d) + t*(fB*q + fC*t + 2.0*e) + f;
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}
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}
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else
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{
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t = 0.0;
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if (tmp1 <= 0.0) {q = 1.0; fSqrDist = fA + 2.0*d + f;}
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else if (d >= 0.0) {q = 0.0; fSqrDist = f;}
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else {q = -d/fA; fSqrDist = d*q + f;}
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}
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}
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else
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//
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// We are in region 1.
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//
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{
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G4double numer = fC + e - fB - d;
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if (numer <= 0.0)
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{
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q = 0.0;
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t = 1.0;
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fSqrDist = fC + 2.0*e + f;
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}
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else
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{
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G4double denom = fA - 2.0*fB + fC;
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if (numer >= denom) {q = 1.0; t = 0.0; fSqrDist = fA + 2.0*d + f;}
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else
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{
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q = numer/denom;
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t = 1.0 - q;
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fSqrDist = q*(fA*q + fB*t + 2.0*d) + t*(fB*q + fC*t + 2.0*e) + f;
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}
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}
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}
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}
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//
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//
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// Do fA check for rounding errors in the distance-squared. It appears that
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// the conventional methods for calculating fSqrDist breaks down when very
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// near to or at the surface (as required by transport).
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// We'll therefore also use the magnitude-squared of the vector displacement.
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// (Note that I've also tried to get around this problem by using the
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// existing equations for
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//
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// fSqrDist = function(fA,fB,fC,d,q,t)
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//
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// and use fA more accurate addition process which minimises errors and
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// breakdown of cummutitivity [where (A+B)+C != A+(B+C)] but this still
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// doesn't work.
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// Calculation from u = D + q*fE1 + t*fE2 is less efficient, but appears
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// more robust.
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//
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if (fSqrDist < 0.0) fSqrDist = 0.;
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G4ThreeVector u = D + q*fE1 + t*fE2;
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G4double u2 = u.mag2();
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//
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// The following (part of the roundoff error check) is from Oliver Merle'q
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// updates.
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//
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if (fSqrDist > u2) fSqrDist = u2;
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return u;
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}
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///////////////////////////////////////////////////////////////////////////////
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//
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// Distance (G4ThreeVector, G4double)
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//
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// Determines the closest distance between point p and the facet. This makes
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// use of G4ThreeVector G4TriangularFacet::Distance, which stores the
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// square of the distance in variable fSqrDist. If approximate methods show
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// the distance is to be greater than minDist, then forget about further
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// computation and return fA very large number.
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//
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G4double G4TriangularFacet::Distance (const G4ThreeVector& p,
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G4double minDist)
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{
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//
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// Start with quicky test to determine if the surface of the sphere enclosing
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// the triangle is any closer to p than minDist. If not, then don't bother
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// about more accurate test.
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//
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G4double dist = kInfinity;
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if ((p-fCircumcentre).mag()-fRadius < minDist)
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{
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//
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// It's possible that the triangle is closer than minDist,
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// so do more accurate assessment.
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//
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dist = Distance(p).mag();
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}
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return dist;
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}
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///////////////////////////////////////////////////////////////////////////////
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//
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// Distance (G4ThreeVector, G4double, G4bool)
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//
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// Determine the distance to point p. kInfinity is returned if either:
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// (1) outgoing is TRUE and the dot product of the normal vector to the facet
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// and the displacement vector from p to the triangle is negative.
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// (2) outgoing is FALSE and the dot product of the normal vector to the facet
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// and the displacement vector from p to the triangle is positive.
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// If approximate methods show the distance is to be greater than minDist, then
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// forget about further computation and return fA very large number.
|
|
//
|
|
// This method has been heavily modified thanks to the valuable comments and
|
|
// corrections of Rickard Holmberg.
|
|
//
|
|
G4double G4TriangularFacet::Distance (const G4ThreeVector& p,
|
|
G4double minDist,
|
|
const G4bool outgoing)
|
|
{
|
|
//
|
|
// Start with quicky test to determine if the surface of the sphere enclosing
|
|
// the triangle is any closer to p than minDist. If not, then don't bother
|
|
// about more accurate test.
|
|
//
|
|
G4double dist = kInfinity;
|
|
if ((p-fCircumcentre).mag()-fRadius < minDist)
|
|
{
|
|
//
|
|
// It's possible that the triangle is closer than minDist,
|
|
// so do more accurate assessment.
|
|
//
|
|
G4ThreeVector v = Distance(p);
|
|
G4double dist1 = sqrt(fSqrDist);
|
|
G4double dir = v.dot(fSurfaceNormal);
|
|
G4bool wrongSide = (dir > 0.0 && !outgoing) || (dir < 0.0 && outgoing);
|
|
if (dist1 <= kCarTolerance)
|
|
{
|
|
//
|
|
// Point p is very close to triangle. Check if it's on the wrong side,
|
|
// in which case return distance of 0.0 otherwise .
|
|
//
|
|
if (wrongSide) dist = 0.0;
|
|
else dist = dist1;
|
|
}
|
|
else if (!wrongSide) dist = dist1;
|
|
}
|
|
return dist;
|
|
}
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// Extent
|
|
//
|
|
// Calculates the furthest the triangle extends in fA particular direction
|
|
// defined by the vector axis.
|
|
//
|
|
G4double G4TriangularFacet::Extent (const G4ThreeVector axis)
|
|
{
|
|
G4double ss = GetVertex(0).dot(axis);
|
|
G4double sp = GetVertex(1).dot(axis);
|
|
if (sp > ss) ss = sp;
|
|
sp = GetVertex(2).dot(axis);
|
|
if (sp > ss) ss = sp;
|
|
return ss;
|
|
}
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// Intersect
|
|
//
|
|
// Member function to find the next intersection when going from p in the
|
|
// direction of v. If:
|
|
// (1) "outgoing" is TRUE, only consider the face if we are going out through
|
|
// the face.
|
|
// (2) "outgoing" is FALSE, only consider the face if we are going in through
|
|
// the face.
|
|
// Member functions returns TRUE if there is an intersection, FALSE otherwise.
|
|
// Sets the distance (distance along w), distFromSurface (orthogonal distance)
|
|
// and normal.
|
|
//
|
|
// Also considers intersections that happen with negative distance for small
|
|
// distances of distFromSurface = 0.5*kCarTolerance in the wrong direction.
|
|
// This is to detect kSurface without doing fA full Inside(p) in
|
|
// G4TessellatedSolid::Distance(p,v) calculation.
|
|
//
|
|
// This member function is thanks the valuable work of Rickard Holmberg. PT.
|
|
// However, "gotos" are the Work of the Devil have been exorcised with
|
|
// extreme prejudice!!
|
|
//
|
|
// IMPORTANT NOTE: These calculations are predicated on v being fA unit
|
|
// vector. If G4TessellatedSolid or other classes call this member function
|
|
// with |v| != 1 then there will be errors.
|
|
//
|
|
G4bool G4TriangularFacet::Intersect (const G4ThreeVector& p,
|
|
const G4ThreeVector& v,
|
|
G4bool outgoing,
|
|
G4double& distance,
|
|
G4double& distFromSurface,
|
|
G4ThreeVector& normal)
|
|
{
|
|
//
|
|
// Check whether the direction of the facet is consistent with the vector v
|
|
// and the need to be outgoing or ingoing. If inconsistent, disregard and
|
|
// return false.
|
|
//
|
|
G4double w = v.dot(fSurfaceNormal);
|
|
if ((outgoing && w < -dirTolerance) || (!outgoing && w > dirTolerance))
|
|
{
|
|
distance = kInfinity;
|
|
distFromSurface = kInfinity;
|
|
normal.set(0,0,0);
|
|
return false;
|
|
}
|
|
//
|
|
// Calculate the orthogonal distance from p to the surface containing the
|
|
// triangle. Then determine if we're on the right or wrong side of the
|
|
// surface (at fA distance greater than kCarTolerance to be consistent with
|
|
// "outgoing".
|
|
//
|
|
const G4ThreeVector& p0 = GetVertex(0);
|
|
G4ThreeVector D = p0 - p;
|
|
distFromSurface = D.dot(fSurfaceNormal);
|
|
G4bool wrongSide = (outgoing && distFromSurface < -0.5*kCarTolerance) ||
|
|
(!outgoing && distFromSurface > 0.5*kCarTolerance);
|
|
|
|
if (wrongSide)
|
|
{
|
|
distance = kInfinity;
|
|
distFromSurface = kInfinity;
|
|
normal.set(0,0,0);
|
|
return false;
|
|
}
|
|
|
|
wrongSide = (outgoing && distFromSurface < 0.0)
|
|
|| (!outgoing && distFromSurface > 0.0);
|
|
if (wrongSide)
|
|
{
|
|
//
|
|
// We're slightly on the wrong side of the surface. Check if we're close
|
|
// enough using fA precise distance calculation.
|
|
//
|
|
G4ThreeVector u = Distance(p);
|
|
if (fSqrDist <= kCarTolerance*kCarTolerance)
|
|
{
|
|
//
|
|
// We're very close. Therefore return fA small negative number
|
|
// to pretend we intersect.
|
|
//
|
|
// distance = -0.5*kCarTolerance
|
|
distance = 0.0;
|
|
normal = fSurfaceNormal;
|
|
return true;
|
|
}
|
|
else
|
|
{
|
|
//
|
|
// We're close to the surface containing the triangle, but sufficiently
|
|
// far from the triangle, and on the wrong side compared to the directions
|
|
// of the surface normal and v. There is no intersection.
|
|
//
|
|
distance = kInfinity;
|
|
distFromSurface = kInfinity;
|
|
normal.set(0,0,0);
|
|
return false;
|
|
}
|
|
}
|
|
if (w < dirTolerance && w > -dirTolerance)
|
|
{
|
|
//
|
|
// The ray is within the plane of the triangle. Project the problem into 2D
|
|
// in the plane of the triangle. First try to create orthogonal unit vectors
|
|
// mu and nu, where mu is fE1/|fE1|. This is kinda like
|
|
// the original algorithm due to Rickard Holmberg, but with better
|
|
// mathematical justification than the original method ... however,
|
|
// beware Rickard's was less time-consuming.
|
|
//
|
|
// Note that vprime is not fA unit vector. We need to keep it unnormalised
|
|
// since the values of distance along vprime (s0 and s1) for intersection
|
|
// with the triangle will be used to determine if we cut the plane at the
|
|
// same time.
|
|
//
|
|
G4ThreeVector mu = fE1.unit();
|
|
G4ThreeVector nu = fSurfaceNormal.cross(mu);
|
|
G4TwoVector pprime(p.dot(mu), p.dot(nu));
|
|
G4TwoVector vprime(v.dot(mu), v.dot(nu));
|
|
G4TwoVector P0prime(p0.dot(mu), p0.dot(nu));
|
|
G4TwoVector E0prime(fE1.mag(), 0.0);
|
|
G4TwoVector E1prime(fE2.dot(mu), fE2.dot(nu));
|
|
G4TwoVector loc[2];
|
|
if (G4TessellatedGeometryAlgorithms::IntersectLineAndTriangle2D(pprime,
|
|
vprime, P0prime, E0prime, E1prime, loc))
|
|
{
|
|
//
|
|
// There is an intersection between the line and triangle in 2D.
|
|
// Now check which part of the line intersects with the plane
|
|
// containing the triangle in 3D.
|
|
//
|
|
G4double vprimemag = vprime.mag();
|
|
G4double s0 = (loc[0] - pprime).mag()/vprimemag;
|
|
G4double s1 = (loc[1] - pprime).mag()/vprimemag;
|
|
G4double normDist0 = fSurfaceNormal.dot(s0*v) - distFromSurface;
|
|
G4double normDist1 = fSurfaceNormal.dot(s1*v) - distFromSurface;
|
|
|
|
if ((normDist0 < 0.0 && normDist1 < 0.0)
|
|
|| (normDist0 > 0.0 && normDist1 > 0.0)
|
|
|| (normDist0 == 0.0 && normDist1 == 0.0) )
|
|
{
|
|
distance = kInfinity;
|
|
distFromSurface = kInfinity;
|
|
normal.set(0,0,0);
|
|
return false;
|
|
}
|
|
else
|
|
{
|
|
G4double dnormDist = normDist1 - normDist0;
|
|
if (fabs(dnormDist) < DBL_EPSILON)
|
|
{
|
|
distance = s0;
|
|
normal = fSurfaceNormal;
|
|
if (!outgoing) distFromSurface = -distFromSurface;
|
|
return true;
|
|
}
|
|
else
|
|
{
|
|
distance = s0 - normDist0*(s1-s0)/dnormDist;
|
|
normal = fSurfaceNormal;
|
|
if (!outgoing) distFromSurface = -distFromSurface;
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
distance = kInfinity;
|
|
distFromSurface = kInfinity;
|
|
normal.set(0,0,0);
|
|
return false;
|
|
}
|
|
}
|
|
//
|
|
//
|
|
// Use conventional algorithm to determine the whether there is an
|
|
// intersection. This involves determining the point of intersection of the
|
|
// line with the plane containing the triangle, and then calculating if the
|
|
// point is within the triangle.
|
|
//
|
|
distance = distFromSurface / w;
|
|
G4ThreeVector pp = p + v*distance;
|
|
G4ThreeVector DD = p0 - pp;
|
|
G4double d = fE1.dot(DD);
|
|
G4double e = fE2.dot(DD);
|
|
G4double ss = fB*e - fC*d;
|
|
G4double t = fB*d - fA*e;
|
|
|
|
G4double sTolerance = (fabs(fB)+ fabs(fC) + fabs(d) + fabs(e))*kCarTolerance;
|
|
G4double tTolerance = (fabs(fA)+ fabs(fB) + fabs(d) + fabs(e))*kCarTolerance;
|
|
G4double detTolerance = (fabs(fA)+ fabs(fC) + 2*fabs(fB) )*kCarTolerance;
|
|
|
|
//if (ss < 0.0 || t < 0.0 || ss+t > fDet)
|
|
if (ss < -sTolerance || t < -tTolerance || ( ss+t - fDet ) > detTolerance)
|
|
{
|
|
//
|
|
// The intersection is outside of the triangle.
|
|
//
|
|
distance = distFromSurface = kInfinity;
|
|
normal.set(0,0,0);
|
|
return false;
|
|
}
|
|
else
|
|
{
|
|
//
|
|
// There is an intersection. Now we only need to set the surface normal.
|
|
//
|
|
normal = fSurfaceNormal;
|
|
if (!outgoing) distFromSurface = -distFromSurface;
|
|
return true;
|
|
}
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// GetPointOnFace
|
|
//
|
|
// Auxiliary method, returns a uniform random point on the facet
|
|
//
|
|
G4ThreeVector G4TriangularFacet::GetPointOnFace() const
|
|
{
|
|
G4double u = G4UniformRand();
|
|
G4double v = G4UniformRand();
|
|
if (u+v > 1.) { u = 1. - u; v = 1. - v; }
|
|
return GetVertex(0) + u*fE1 + v*fE2;
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// GetArea
|
|
//
|
|
// Auxiliary method for returning the surface fArea
|
|
//
|
|
G4double G4TriangularFacet::GetArea() const
|
|
{
|
|
return fArea;
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////
|
|
//
|
|
G4GeometryType G4TriangularFacet::GetEntityType () const
|
|
{
|
|
return "G4TriangularFacet";
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////
|
|
//
|
|
G4ThreeVector G4TriangularFacet::GetSurfaceNormal () const
|
|
{
|
|
return fSurfaceNormal;
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////
|
|
//
|
|
void G4TriangularFacet::SetSurfaceNormal (const G4ThreeVector& normal)
|
|
{
|
|
fSurfaceNormal = normal;
|
|
}
|