godot/thirdparty/bullet/BulletSoftBody/BulletReducedDeformableBody/btReducedDeformableBodyHelp...

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#include "btReducedDeformableBodyHelpers.h"
#include "../btSoftBodyHelpers.h"
#include <iostream>
#include <string>
#include <sstream>
btReducedDeformableBody* btReducedDeformableBodyHelpers::createReducedDeformableObject(btSoftBodyWorldInfo& worldInfo, const std::string& file_path, const std::string& vtk_file, const int num_modes, bool rigid_only) {
std::string filename = file_path + vtk_file;
btReducedDeformableBody* rsb = btReducedDeformableBodyHelpers::createFromVtkFile(worldInfo, filename.c_str());
rsb->setReducedModes(num_modes, rsb->m_nodes.size());
btReducedDeformableBodyHelpers::readReducedDeformableInfoFromFiles(rsb, file_path.c_str());
rsb->disableReducedModes(rigid_only);
return rsb;
}
btReducedDeformableBody* btReducedDeformableBodyHelpers::createFromVtkFile(btSoftBodyWorldInfo& worldInfo, const char* vtk_file)
{
std::ifstream fs;
fs.open(vtk_file);
btAssert(fs);
typedef btAlignedObjectArray<int> Index;
std::string line;
btAlignedObjectArray<btVector3> X;
btVector3 position;
btAlignedObjectArray<Index> indices;
bool reading_points = false;
bool reading_tets = false;
size_t n_points = 0;
size_t n_tets = 0;
size_t x_count = 0;
size_t indices_count = 0;
while (std::getline(fs, line))
{
std::stringstream ss(line);
if (line.size() == (size_t)(0))
{
}
else if (line.substr(0, 6) == "POINTS")
{
reading_points = true;
reading_tets = false;
ss.ignore(128, ' '); // ignore "POINTS"
ss >> n_points;
X.resize(n_points);
}
else if (line.substr(0, 5) == "CELLS")
{
reading_points = false;
reading_tets = true;
ss.ignore(128, ' '); // ignore "CELLS"
ss >> n_tets;
indices.resize(n_tets);
}
else if (line.substr(0, 10) == "CELL_TYPES")
{
reading_points = false;
reading_tets = false;
}
else if (reading_points)
{
btScalar p;
ss >> p;
position.setX(p);
ss >> p;
position.setY(p);
ss >> p;
position.setZ(p);
//printf("v %f %f %f\n", position.getX(), position.getY(), position.getZ());
X[x_count++] = position;
}
else if (reading_tets)
{
int d;
ss >> d;
if (d != 4)
{
printf("Load deformable failed: Only Tetrahedra are supported in VTK file.\n");
fs.close();
return 0;
}
ss.ignore(128, ' '); // ignore "4"
Index tet;
tet.resize(4);
for (size_t i = 0; i < 4; i++)
{
ss >> tet[i];
//printf("%d ", tet[i]);
}
//printf("\n");
indices[indices_count++] = tet;
}
}
btReducedDeformableBody* rsb = new btReducedDeformableBody(&worldInfo, n_points, &X[0], 0);
for (int i = 0; i < n_tets; ++i)
{
const Index& ni = indices[i];
rsb->appendTetra(ni[0], ni[1], ni[2], ni[3]);
{
rsb->appendLink(ni[0], ni[1], 0, true);
rsb->appendLink(ni[1], ni[2], 0, true);
rsb->appendLink(ni[2], ni[0], 0, true);
rsb->appendLink(ni[0], ni[3], 0, true);
rsb->appendLink(ni[1], ni[3], 0, true);
rsb->appendLink(ni[2], ni[3], 0, true);
}
}
btSoftBodyHelpers::generateBoundaryFaces(rsb);
rsb->initializeDmInverse();
rsb->m_tetraScratches.resize(rsb->m_tetras.size());
rsb->m_tetraScratchesTn.resize(rsb->m_tetras.size());
printf("Nodes: %u\r\n", rsb->m_nodes.size());
printf("Links: %u\r\n", rsb->m_links.size());
printf("Faces: %u\r\n", rsb->m_faces.size());
printf("Tetras: %u\r\n", rsb->m_tetras.size());
fs.close();
return rsb;
}
void btReducedDeformableBodyHelpers::readReducedDeformableInfoFromFiles(btReducedDeformableBody* rsb, const char* file_path)
{
// read in eigenmodes, stiffness and mass matrices
std::string eigenvalues_file = std::string(file_path) + "eigenvalues.bin";
btReducedDeformableBodyHelpers::readBinaryVec(rsb->m_eigenvalues, rsb->m_nReduced, eigenvalues_file.c_str());
std::string Kr_file = std::string(file_path) + "K_r_diag_mat.bin";
btReducedDeformableBodyHelpers::readBinaryVec(rsb->m_Kr, rsb->m_nReduced, Kr_file.c_str());
// std::string Mr_file = std::string(file_path) + "M_r_diag_mat.bin";
// btReducedDeformableBodyHelpers::readBinaryVec(rsb->m_Mr, rsb->m_nReduced, Mr_file.c_str());
std::string modes_file = std::string(file_path) + "modes.bin";
btReducedDeformableBodyHelpers::readBinaryMat(rsb->m_modes, rsb->m_nReduced, 3 * rsb->m_nFull, modes_file.c_str());
// read in full nodal mass
std::string M_file = std::string(file_path) + "M_diag_mat.bin";
btAlignedObjectArray<btScalar> mass_array;
btReducedDeformableBodyHelpers::readBinaryVec(mass_array, rsb->m_nFull, M_file.c_str());
rsb->setMassProps(mass_array);
// calculate the inertia tensor in the local frame
rsb->setInertiaProps();
// other internal initialization
rsb->internalInitialization();
}
// read in a vector from the binary file
void btReducedDeformableBodyHelpers::readBinaryVec(btReducedDeformableBody::tDenseArray& vec,
const unsigned int n_size, // #entries read
const char* file)
{
std::ifstream f_in(file, std::ios::in | std::ios::binary);
// first get size
unsigned int size=0;
f_in.read((char*)&size, 4);//sizeof(unsigned int));
btAssert(size >= n_size); // make sure the #requested mode is smaller than the #available modes
// read data
vec.resize(n_size);
double temp;
for (unsigned int i = 0; i < n_size; ++i)
{
f_in.read((char*)&temp, sizeof(double));
vec[i] = btScalar(temp);
}
f_in.close();
}
// read in a matrix from the binary file
void btReducedDeformableBodyHelpers::readBinaryMat(btReducedDeformableBody::tDenseMatrix& mat,
const unsigned int n_modes, // #modes, outer array size
const unsigned int n_full, // inner array size
const char* file)
{
std::ifstream f_in(file, std::ios::in | std::ios::binary);
// first get size
unsigned int v_size=0;
f_in.read((char*)&v_size, 4);//sizeof(unsigned int));
btAssert(v_size >= n_modes * n_full); // make sure the #requested mode is smaller than the #available modes
// read data
mat.resize(n_modes);
for (int i = 0; i < n_modes; ++i)
{
for (int j = 0; j < n_full; ++j)
{
double temp;
f_in.read((char*)&temp, sizeof(double));
if (mat[i].size() != n_modes)
mat[i].resize(n_full);
mat[i][j] = btScalar(temp);
}
}
f_in.close();
}
void btReducedDeformableBodyHelpers::calculateLocalInertia(btVector3& inertia, const btScalar mass, const btVector3& half_extents, const btVector3& margin)
{
btScalar lx = btScalar(2.) * (half_extents[0] + margin[0]);
btScalar ly = btScalar(2.) * (half_extents[1] + margin[1]);
btScalar lz = btScalar(2.) * (half_extents[2] + margin[2]);
inertia.setValue(mass / (btScalar(12.0)) * (ly * ly + lz * lz),
mass / (btScalar(12.0)) * (lx * lx + lz * lz),
mass / (btScalar(12.0)) * (lx * lx + ly * ly));
}