src/math/Triangle.cpp

/* Copyright (c) 2008 The University of Notre Dame. All Rights Reserved.
 *
 * The University of Notre Dame grants you ("Licensee") a
 * non-exclusive, royalty free, license to use, modify and
 * redistribute this software in source and binary code form, provided
 * that the following conditions are met:
 *
 * 1. Acknowledgement of the program authors must be made in any
 *    publication of scientific results based in part on use of the
 *    program.  An acceptable form of acknowledgement is citation of
 *    the article in which the program was described (Matthew
 *    A. Meineke, Charles F. Vardeman II, Teng Lin, Christopher
 *    J. Fennell and J. Daniel Gezelter, "OOPSE: An Object-Oriented
 *    Parallel Simulation Engine for Molecular Dynamics,"
 *    J. Comput. Chem. 26, pp. 252-271 (2005))
 *
 * 2. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 3. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the
 *    distribution.
 *
 * This software is provided "AS IS," without a warranty of any
 * kind. All express or implied conditions, representations and
 * warranties, including any implied warranty of merchantability,
 * fitness for a particular purpose or non-infringement, are hereby
 * excluded.  The University of Notre Dame and its licensors shall not
 * be liable for any damages suffered by licensee as a result of
 * using, modifying or distributing the software or its
 * derivatives. In no event will the University of Notre Dame or its
 * licensors be liable for any lost revenue, profit or data, or for
 * direct, indirect, special, consequential, incidental or punitive
 * damages, however caused and regardless of the theory of liability,
 * arising out of the use of or inability to use software, even if the
 * University of Notre Dame has been advised of the possibility of
 * such damages.
 *
 *
 *  Triangle.cpp
 *
 *  Purpose: Provide basic triangle object for OOPSE
 *
 *  Created by Charles F. Vardeman II on 29 July 2008.
 *  @author  Charles F. Vardeman II
 *  @version $Id: Triangle.cpp,v 1.3 2009-05-13 22:27:29 gezelter Exp $
 *
 */

#include "math/Triangle.hpp"

using namespace oopse;


Triangle::Triangle() : HaveNormal_(false), HaveCentroid_(false),
                       HaveArea_(false), area_(0.0), normal_(V3Zero), 
                       centroid_(V3Zero), facetVelocity_(V3Zero), mass_(0.0),
                       a_(V3Zero), b_(V3Zero), c_(V3Zero){
}

void Triangle::addVertices(Vector3d P1, Vector3d P2, Vector3d P3){
  vertices_[0] = P1;
  vertices_[1] = P2;
  vertices_[2] = P3;

  // Compute some quantites like a,b,c
  a_ = P1-P2;
  b_ = P1-P3;
  c_ = P2-P3;  
}


RealType Triangle::computeArea(){
  HaveArea_ = true;
  area_ = getNormal().length() * 0.5;
  return area_;
}

Vector3d Triangle::computeNormal(){
  HaveNormal_ = true;
  normal_ = cross(a_,b_);
  return normal_;
}

Vector3d Triangle::computeCentroid(){
  HaveCentroid_ = true;
  centroid_ = (vertices_[0] + vertices_[1] + vertices_[2])/3.0;
  return centroid_;
}


Mat3x3d Triangle::computeHydrodynamicTensor(RealType viscosity) {
  
  Vector3d u0 = -a_;
  Vector3d v0 = centroid_ - vertices_[0];
  RealType s0 = 0.5*cross(u0,v0).length();
  
  Vector3d u1 = -c_;
  Vector3d v1 = centroid_ - vertices_[1];
  RealType s1 = 0.5*cross(u1,v1).length();
  
  Vector3d u2 = b_;
  Vector3d v2 = centroid_ - vertices_[2];
  RealType s2 = 0.5*cross(u2,v2).length();
  
  Mat3x3d H;
  H = hydro_tensor(centroid_,centroid_,vertices_[1],vertices_[0],s0,viscosity)+
    hydro_tensor(centroid_,centroid_,vertices_[1],vertices_[2],s1,viscosity)+
    hydro_tensor(centroid_,centroid_,vertices_[2],vertices_[0],s2,viscosity);

  return H.inverse();
}

Mat3x3d Triangle::hydro_tensor(
                               const Vector3d& ri,
                               const Vector3d& rj0,
                               const Vector3d& rj1,
                               const Vector3d& rj2,
                               RealType s, RealType viscosity){
  
  Vector3d v2 = (rj0 + rj1 + rj2)/3.0;  // sub-centroid
  Vector3d dr = ri - v2;                // real centroid to sub-centroid
  RealType l2 = 1.0/dr.lengthSquare();  
 
  Mat3x3d G;
  G = (SquareMatrix3<RealType>::identity() + outProduct(dr,dr)*l2)*sqrt(l2);

  G *= 0.125/3.14159285358979;
  G *= s/viscosity;
  return G;
}
Revision:	1344
Committed:	Wed May 13 22:27:29 2009 UTC (16 years, 5 months ago) by gezelter
Original Path:	*trunk/src/math/Triangle.cpp*
File size:	4511 byte(s)
Log Message:	Adding boundary element hydrodynamics to SMIPD.
#	User	Rev	Content
1	chuckv	1316	/* Copyright (c) 2008 The University of Notre Dame. All Rights Reserved.
2			*
3			* The University of Notre Dame grants you ("Licensee") a
4			* non-exclusive, royalty free, license to use, modify and
5			* redistribute this software in source and binary code form, provided
6			* that the following conditions are met:
7			*
8			* 1. Acknowledgement of the program authors must be made in any
9			* publication of scientific results based in part on use of the
10			* program. An acceptable form of acknowledgement is citation of
11			* the article in which the program was described (Matthew
12			* A. Meineke, Charles F. Vardeman II, Teng Lin, Christopher
13			* J. Fennell and J. Daniel Gezelter, "OOPSE: An Object-Oriented
14			* Parallel Simulation Engine for Molecular Dynamics,"
15			* J. Comput. Chem. 26, pp. 252-271 (2005))
16			*
17			* 2. Redistributions of source code must retain the above copyright
18			* notice, this list of conditions and the following disclaimer.
19			*
20			* 3. Redistributions in binary form must reproduce the above copyright
21			* notice, this list of conditions and the following disclaimer in the
22			* documentation and/or other materials provided with the
23			* distribution.
24			*
25			* This software is provided "AS IS," without a warranty of any
26			* kind. All express or implied conditions, representations and
27			* warranties, including any implied warranty of merchantability,
28			* fitness for a particular purpose or non-infringement, are hereby
29			* excluded. The University of Notre Dame and its licensors shall not
30			* be liable for any damages suffered by licensee as a result of
31			* using, modifying or distributing the software or its
32			* derivatives. In no event will the University of Notre Dame or its
33			* licensors be liable for any lost revenue, profit or data, or for
34			* direct, indirect, special, consequential, incidental or punitive
35			* damages, however caused and regardless of the theory of liability,
36			* arising out of the use of or inability to use software, even if the
37			* University of Notre Dame has been advised of the possibility of
38			* such damages.
39			*
40			*
41			* Triangle.cpp
42			*
43			* Purpose: Provide basic triangle object for OOPSE
44			*
45			* Created by Charles F. Vardeman II on 29 July 2008.
46			* @author Charles F. Vardeman II
47	gezelter	1344	* @version $Id: Triangle.cpp,v 1.3 2009-05-13 22:27:29 gezelter Exp $
48	chuckv	1316	*
49			*/
50
51			#include "math/Triangle.hpp"
52
53			using namespace oopse;
54
55
56	gezelter	1344	Triangle::Triangle() : HaveNormal_(false), HaveCentroid_(false),
57			HaveArea_(false), area_(0.0), normal_(V3Zero),
58			centroid_(V3Zero), facetVelocity_(V3Zero), mass_(0.0),
59			a_(V3Zero), b_(V3Zero), c_(V3Zero){
60	chuckv	1316	}
61
62			void Triangle::addVertices(Vector3d P1, Vector3d P2, Vector3d P3){
63			vertices_[0] = P1;
64			vertices_[1] = P2;
65			vertices_[2] = P3;
66
67			// Compute some quantites like a,b,c
68			a_ = P1-P2;
69			b_ = P1-P3;
70	chuckv	1325	c_ = P2-P3;
71	chuckv	1316	}
72
73
74			RealType Triangle::computeArea(){
75			HaveArea_ = true;
76			area_ = getNormal().length() * 0.5;
77			return area_;
78			}
79
80			Vector3d Triangle::computeNormal(){
81			HaveNormal_ = true;
82			normal_ = cross(a_,b_);
83			return normal_;
84			}
85
86			Vector3d Triangle::computeCentroid(){
87			HaveCentroid_ = true;
88			centroid_ = (vertices_[0] + vertices_[1] + vertices_[2])/3.0;
89			return centroid_;
90			}
91	gezelter	1344
92
93			Mat3x3d Triangle::computeHydrodynamicTensor(RealType viscosity) {
94
95			Vector3d u0 = -a_;
96			Vector3d v0 = centroid_ - vertices_[0];
97			RealType s0 = 0.5*cross(u0,v0).length();
98
99			Vector3d u1 = -c_;
100			Vector3d v1 = centroid_ - vertices_[1];
101			RealType s1 = 0.5*cross(u1,v1).length();
102
103			Vector3d u2 = b_;
104			Vector3d v2 = centroid_ - vertices_[2];
105			RealType s2 = 0.5*cross(u2,v2).length();
106
107			Mat3x3d H;
108			H = hydro_tensor(centroid_,centroid_,vertices_[1],vertices_[0],s0,viscosity)+
109			hydro_tensor(centroid_,centroid_,vertices_[1],vertices_[2],s1,viscosity)+
110			hydro_tensor(centroid_,centroid_,vertices_[2],vertices_[0],s2,viscosity);
111
112			return H.inverse();
113			}
114
115			Mat3x3d Triangle::hydro_tensor(
116			const Vector3d& ri,
117			const Vector3d& rj0,
118			const Vector3d& rj1,
119			const Vector3d& rj2,
120			RealType s, RealType viscosity){
121
122			Vector3d v2 = (rj0 + rj1 + rj2)/3.0; // sub-centroid
123			Vector3d dr = ri - v2; // real centroid to sub-centroid
124			RealType l2 = 1.0/dr.lengthSquare();
125
126			Mat3x3d G;
127			G = (SquareMatrix3<RealType>::identity() + outProduct(dr,dr)l2)sqrt(l2);
128
129			G *= 0.125/3.14159285358979;
130			G *= s/viscosity;
131			return G;
132			}