| //##################################################################### |
| // Copyright 2003-2004, Ron Fedkiw, Eran Guendelman, Joseph Teran. |
| // This file is part of PhysBAM whose distribution is governed by the license contained in the accompanying file PHYSBAM_COPYRIGHT.txt. |
| //##################################################################### |
| // Class MASS_PROPERTIES_3D |
| //##################################################################### |
| // |
| // Based on Brian Mirtich's volInt.c implementation (copyright 1995) which is based on "Fast and Accurate Computation of Polyhedral Mass Properties" by Mirtich. |
| // |
| //##################################################################### |
| #ifndef __MASS_PROPERTIES_3D__ |
| #define __MASS_PROPERTIES_3D__ |
| |
| #include "../Matrices_And_Vectors/VECTOR_3D.h" |
| #include "../Matrices_And_Vectors/QUATERNION.h" |
| #include "../Particles/SOLIDS_PARTICLE.h" |
| namespace PhysBAM |
| { |
| |
| template<class T> class TRIANGULATED_SURFACE; |
| template<class T> class TRIANGLE_3D; |
| template<class T> class SYMMETRIC_MATRIX_3X3; |
| |
| template<class T> |
| class MASS_PROPERTIES_3D |
| { |
| private: |
| TRIANGULATED_SURFACE<T>& triangulated_surface; |
| mutable T mass, density; |
| bool given_mass; // either mass or density is prescribed |
| int A, B, C; // alpha, beta, gamma (axis permutation) |
| T P1, Pa, Pb, Paa, Pab, Pbb, Paaa, Paab, Pabb, Pbbb; // projection integrals |
| T Fa, Fb, Fc, Faa, Fbb, Fcc, Fab, Fbc, Fca, Faaa, Fbbb, Fccc, Faab, Fbbc, Fcca; // face integrals |
| T volume; // surface area if thin shell |
| VECTOR_3D<T> T1, T2, TP; // volume integrals |
| |
| public: |
| MASS_PROPERTIES_3D (TRIANGULATED_SURFACE<T>& triangulated_surface_input, const bool thin_shell = false) |
| : triangulated_surface (triangulated_surface_input) |
| { |
| if (!triangulated_surface.triangle_list) triangulated_surface.Update_Triangle_List(); |
| |
| Set_Density(); |
| Set_Mass(); // leaves the given_mass=true |
| |
| if (thin_shell) Compute_Thin_Shell_Integrals(); |
| else Compute_Volume_Integrals(); |
| } |
| |
| void Set_Mass (T mass_input = 1) |
| { |
| mass = mass_input; |
| given_mass = true; |
| } |
| |
| void Set_Density (T density_input = 1) |
| { |
| density = density_input; |
| given_mass = false; |
| } |
| |
| T Get_Volume() const |
| { |
| return volume; |
| } |
| |
| T Get_Surface_Area() const |
| { |
| return volume; |
| } |
| |
| //##################################################################### |
| public: |
| void Get_Center_Of_Mass_And_Inertia_Tensor (VECTOR_3D<T>& center_of_mass, SYMMETRIC_MATRIX_3X3<T>& inertia_tensor) const; |
| void Transform_To_Object_Frame (VECTOR_3D<T>& center_of_mass, QUATERNION<T>& orientation, DIAGONAL_MATRIX_3X3<T>& moment_of_inertia, SOLIDS_PARTICLE<T, VECTOR_3D<T> >& particles) const; |
| private: |
| void Compute_Volume_Integrals(); |
| void Compute_Thin_Shell_Integrals(); |
| void Compute_Face_Integrals (const TRIANGLE_3D<T>& triangle); |
| void Compute_Projection_Integrals (const TRIANGLE_3D<T>& triangle); |
| //##################################################################### |
| }; |
| } |
| #endif |
