static void computeLevelset(GModel *gm, cartesianBox<double> &box)
{
// tolerance for desambiguation
const double tol = box.getLC() * 1.e-12;
std::vector<SPoint3> nodes;
std::vector<int> indices;
for (cartesianBox<double>::valIter it = box.nodalValuesBegin();
it != box.nodalValuesEnd(); ++it){
nodes.push_back(box.getNodeCoordinates(it->first));
indices.push_back(it->first);
}
Msg::Info(" %d nodes in the grid at level %d", (int)nodes.size(), box.getLevel());
std::vector<double> dist, localdist;
std::vector<SPoint3> dummy;
for (GModel::fiter fit = gm->firstFace(); fit != gm->lastFace(); fit++){
for (int i = 0; i < (*fit)->stl_triangles.size(); i += 3){
int i1 = (*fit)->stl_triangles[i];
int i2 = (*fit)->stl_triangles[i + 1];
int i3 = (*fit)->stl_triangles[i + 2];
GPoint p1 = (*fit)->point((*fit)->stl_vertices[i1]);
GPoint p2 = (*fit)->point((*fit)->stl_vertices[i2]);
GPoint p3 = (*fit)->point((*fit)->stl_vertices[i3]);
SPoint2 p = ((*fit)->stl_vertices[i1] + (*fit)->stl_vertices[i2] +
(*fit)->stl_vertices[i3]) * 0.33333333;
SVector3 N = (*fit)->normal(p);
SPoint3 P1(p1.x(), p1.y(), p1.z());
SPoint3 P2(p2.x(), p2.y(), p2.z());
SPoint3 P3(p3.x(), p3.y(), p3.z());
SVector3 NN(crossprod(P2 - P1, P3 - P1));
if (dot(NN, N) > 0)
signedDistancesPointsTriangle(localdist, dummy, nodes, P1, P2, P3);
else
signedDistancesPointsTriangle(localdist, dummy, nodes, P2, P1, P3);
if(dist.empty())
dist = localdist;
else{
for (unsigned int j = 0; j < localdist.size(); j++){
// FIXME: if there is an ambiguity assume we are inside (to
// avoid holes in the structure). This is definitely just a
// hack, as it could create pockets of matter outside the
// structure...
if(dist[j] * localdist[j] < 0 &&
fabs(fabs(dist[j]) - fabs(localdist[j])) < tol){
dist[j] = std::max(dist[j], localdist[j]);
}
else{
dist[j] = (fabs(dist[j]) < fabs(localdist[j])) ? dist[j] : localdist[j];
}
}
}
}
}
for (unsigned int j = 0; j < dist.size(); j++)
box.setNodalValue(indices[j], dist[j]);
if(box.getChildBox()) computeLevelset(gm, *box.getChildBox());
}
int main()
{
int dimension = 3;
auto resolution = Manta::Vec3i(128);
if (dimension == 2) resolution.z = 1;
auto main_solver = Manta::FluidSolver(resolution, dimension);
main_solver.setTimeStep(0.5f);
Real minParticles = pow(2, dimension);
Real radiusFactor = 1.0f;
// solver grids
auto flags = Manta::FlagGrid(&main_solver);
auto phi = Manta::LevelsetGrid(&main_solver);
auto vel = Manta::MACGrid(&main_solver);
auto vel_old = Manta::MACGrid(&main_solver);
auto pressure = Manta::Grid<Real>(&main_solver);
auto tmp_vec3 = Manta::Grid<Manta::Vec3>(&main_solver);
auto tstGrid = Manta::Grid<Real>(&main_solver);
// particles
auto pp = Manta::BasicParticleSystem(&main_solver);
auto pVel = Manta::PdataVec3(&pp);
auto pTest = Manta::PdataReal(&pp);
auto mesh = Manta::Mesh(&main_solver);
// acceleration data for particle nbs
auto pindex = Manta::ParticleIndexSystem(&main_solver);
auto gpi = Manta::Grid<int>(&main_solver);
int setup = 0;
int boundaryWidth = 1;
flags.initDomain(boundaryWidth);
auto fluidVel = Manta::Sphere(&main_solver, Manta::Vec3(0.0f), 1.0f);
Manta::Vec3 fluidSetVel;
if (setup == 0)
{
// breakin dam
auto fluidbox = Manta::Box(&main_solver, Manta::Vec3::Invalid,
Manta::Vec3(0.0f, 0.0f, 0.0f),
Manta::Vec3(resolution.x * 0.4f, resolution.y * 0.6f, resolution.z * 0.1f));
phi.copyFrom(fluidbox.computeLevelset());
} else if (setup == 1)
{
// drop into box
auto fluidbasin = Manta::Box(&main_solver, Manta::Vec3::Invalid,
Manta::Vec3(0.0f, 0.0f, 0.0f),
Manta::Vec3(resolution.x * 1.0f, resolution.y * 0.1f, resolution.z * 1.0f));
auto dropCenter = Manta::Vec3(0.5f, 0.3f, 0.5f);
Real dropRadius = 0.1f;
auto fluidDrop = Manta::Sphere(&main_solver, Manta::Vec3(resolution.x * dropCenter.x, resolution.y * dropCenter.y, resolution.z * dropCenter.z),
resolution.x * dropRadius);
fluidVel = Manta::Sphere(&main_solver, Manta::Vec3(resolution.x * dropCenter.x, resolution.y * dropCenter.y, resolution.z * dropCenter.z),
resolution.x * (dropRadius + 0.05f));
fluidSetVel = Manta::Vec3(0.0f, -1.0f, 0.0f);
phi.copyFrom(fluidbasin.computeLevelset());
phi.join(fluidDrop.computeLevelset());
}
flags.updateFromLevelset(phi);
Manta::sampleLevelsetWithParticles(phi, flags, pp, 2, 0.05f);
if (setup == 1)
{
fluidVel.applyToGrid(&vel, fluidSetVel);
Manta::mapGridToPartsVec3(vel, pp, pVel);
}
Manta::testInitGridWithPos(tstGrid);
pTest.setConst(0.1f);
for (int t = 0; t < 250; t++)
{
// FLIP
pp.advectInGrid(flags, vel, Manta::IntegrationMode::IntRK4, false);
// make sure we have velocities throught liquid region
Manta::mapParticlesToMAC(flags, vel, vel_old, pp, pVel, &tmp_vec3);
Manta::extrapolateMACFromWeight(vel, tmp_vec3, 2);
Manta::markFluidCells(pp, flags);
// create approximate surface level set, resample particles
Manta::gridParticleIndex(pp, pindex, flags, gpi);
Manta::unionParticleLevelset(pp, pindex, flags, gpi, phi, radiusFactor);
Manta::resetOutflow(flags, nullptr, &pp, nullptr, &gpi,&pindex);
// extend levelset somewhat, needed by particle resampling in adjustNumber
Manta::extrapolateLsSimple(phi, 4, true);
// forces and pressure solve
Manta::addGravity(flags, vel, Manta::Vec3(0.0f, -0.001f, 0.0f));
Manta::setWallBcs(flags, vel);
Manta::solvePressure(vel, pressure, flags, &phi);
Manta::setWallBcs(flags, vel);
// set source grids for resampling, used in adjustNumber!
pVel.setSource(&vel, true);
pTest.setSource(&tstGrid);
Manta::adjustNumber(pp, vel, flags, 1 * minParticles, 2 * minParticles, phi, radiusFactor);
// make sure we have proper velocities
Manta::extrapolateMACSimple(flags, vel);
Manta::flipVelocityUpdate(flags, vel, vel_old, pp, pVel, 0.97f);
if (dimension == 3) phi.createMesh(mesh);
main_solver.step();
// generate data directly and for flip03_gen.py surface generation scene
std::stringstream filename1, filename2;
filename1 << "simulation data\\flip02_surface\\fluidsurface_final_" << std::setw(4) << std::setfill('0') << t << ".bobj.gz";
filename2 << "simulation data\\flip02_surface\\flipParts_" << std::setw(4) << std::setfill('0') << t << ".uni";
mesh.save(filename1.str());
pp.save(filename2.str());
}
}
int main(int argc,char *argv[])
{
if(argc < 6){
printf("Usage: %s file lx ly lz rmax [levels=1] [refcs=1]\n", argv[0]);
printf("where\n");
printf(" 'file' contains a CAD model\n");
printf(" 'lx', 'ly' and 'lz' are the sizes of the elements along the"
" x-, y- and z-axis at the coarsest level\n");
printf(" 'rmax' is the radius of the largest sphere that can be inscribed"
" in the structure\n");
printf(" 'levels' sets the number of levels in the grid\n");
printf(" 'refcs' selects if curved surfaces should be refined\n");
return -1;
}
GmshInitialize();
GmshSetOption("General", "Terminal", 1.);
GmshMergeFile(argv[1]);
double lx = atof(argv[2]), ly = atof(argv[3]), lz = atof(argv[4]);
double rmax = atof(argv[5]);
int levels = (argc > 6) ? atof(argv[6]) : 1;
int refineCurvedSurfaces = (argc > 7) ? atof(argv[7]) : 1;
// minimum distance between points in the cloud at the coarsest
// level
double sampling = std::min(rmax, std::min(lx, std::min(ly, lz)));
// radius of the "tube" created around parts to refine at the
// coarsest level
double rtube = std::max(lx, std::max(ly, lz)) * 2.;
GModel *gm = GModel::current();
std::vector<SPoint3> points;
Msg::Info("Filling coarse point cloud on surfaces");
for (GModel::fiter fit = gm->firstFace(); fit != gm->lastFace(); fit++)
(*fit)->fillPointCloud(sampling, &points);
Msg::Info(" %d points in the surface cloud", (int)points.size());
std::vector<SPoint3> refinePoints;
if(levels > 1){
double s = sampling / pow(2., levels - 1);
Msg::Info("Filling refined point cloud on curves and curved surfaces");
for (GModel::eiter eit = gm->firstEdge(); eit != gm->lastEdge(); eit++)
fillPointCloud(*eit, s, refinePoints);
// FIXME: refine this by computing e.g. "mean" curvature
if(refineCurvedSurfaces){
for (GModel::fiter fit = gm->firstFace(); fit != gm->lastFace(); fit++)
if((*fit)->geomType() != GEntity::Plane)
(*fit)->fillPointCloud(2 * s, &refinePoints);
}
Msg::Info(" %d points in the refined cloud", (int)refinePoints.size());
}
SBoundingBox3d bb;
for(unsigned int i = 0; i < points.size(); i++) bb += points[i];
for(unsigned int i = 0; i < refinePoints.size(); i++) bb += refinePoints[i];
bb.scale(1.21, 1.21, 1.21);
SVector3 range = bb.max() - bb.min();
int NX = range.x() / lx;
int NY = range.y() / ly;
int NZ = range.z() / lz;
if(NX < 2) NX = 2;
if(NY < 2) NY = 2;
if(NZ < 2) NZ = 2;
Msg::Info(" bounding box min: %g %g %g -- max: %g %g %g",
bb.min().x(), bb.min().y(), bb.min().z(),
bb.max().x(), bb.max().y(), bb.max().z());
Msg::Info(" Nx=%d Ny=%d Nz=%d", NX, NY, NZ);
cartesianBox<double> box(bb.min().x(), bb.min().y(), bb.min().z(),
SVector3(range.x(), 0, 0),
SVector3(0, range.y(), 0),
SVector3(0, 0, range.z()),
NX, NY, NZ, levels);
Msg::Info("Inserting active cells in the cartesian grid");
Msg::Info(" level %d", box.getLevel());
for (unsigned int i = 0; i < points.size(); i++)
insertActiveCells(points[i].x(), points[i].y(), points[i].z(), rmax, box);
cartesianBox<double> *parent = &box, *child;
while((child = parent->getChildBox())){
Msg::Info(" level %d", child->getLevel());
for(unsigned int i = 0; i < refinePoints.size(); i++)
insertActiveCells(refinePoints[i].x(), refinePoints[i].y(), refinePoints[i].z(),
rtube / pow(2., (levels - child->getLevel())), *child);
parent = child;
}
// remove child cells that do not entirely fill parent cell or for
// which there is no parent neighbor; then remove parent cells that
// have children
Msg::Info("Removing cells to match X-FEM mesh topology constraints");
removeBadChildCells(&box);
removeParentCellsWithChildren(&box);
// we generate duplicate nodes at this point so we can easily access
// cell values at each level; we will clean up by renumbering after
// filtering
Msg::Info("Initializing nodal values in the cartesian grid");
box.createNodalValues();
Msg::Info("Computing levelset on the cartesian grid");
computeLevelset(gm, box);
Msg::Info("Removing cells outside the structure");
removeOutsideCells(&box);
Msg::Info("Renumbering mesh vertices across levels");
box.renumberNodes();
bool decomposeInSimplex = false;
box.writeMSH("yeah.msh", decomposeInSimplex);
Msg::Info("Done!");
GmshFinalize();
}
