36_test_ann_vs_geom_ellipsoid.cpp

This is an example of how to use the netdem library.

#include "contact_solver_factory.hpp"
#include "distribution_uniform.hpp"
#include "general_net.hpp"
#include "igl_wrapper.hpp"
#include "mlpack_utils.hpp"
#include "model_linear_spring.hpp"
#include "particle.hpp"
#include "regression_net.hpp"
#include "shape_ellipsoid.hpp"
#include "shape_plane.hpp"
#include "solver_gjk_pp.hpp"
#include "spherical_voronoi.hpp"
#include "utils_math.hpp"
#include <fstream>
#include <iostream>
#include <random>
#include <sstream>
#include <string>
 
using namespace netdem;
using namespace std;
 
void TestANNvsGeometricEllipsoid() {
  // load particle
  Ellipsoid ellipsoid = Ellipsoid(1, 1, 2);
  ellipsoid.SetSize(1.0);
 
  Particle obj_p1 = Particle(&ellipsoid);
  Particle obj_p2 = Particle(&ellipsoid);
  cout << "particle created ... " << endl;
 
  SolverGJKPP cnt_solver;
  LinearSpring cnt_model;
 
  string root_dir = "local/examples/netdem/ann_models/ellipsoid_ellipsoid/";
  GeneralNet classifier;
  classifier.Load(root_dir + "ann_classifier.xml", "detection");
  RegressionNet regressor;
  regressor.Load(root_dir + "ann_regressor.xml", "resolution");
 
  double dist_max = obj_p2.shape->GetBoundSphereRadius() * 2;
  double dist_min = dist_max / 2 * 0.9;
  double dist_range = dist_max - dist_min;
 
  // random generator
  UniformDistribution uniform_dist(0.0, 1.0);
 
  // use spherical centroidal voronoi to sample uniform unit VecXT
  VecXT<Vec3d> vertices = SphericalVoronoi::Solve(1000, 10000, 1.0e-4);
  VecXT<Vec3i> facets;
  IGLWrapper::ConvexHull(vertices, &vertices, &facets);
 
  // random cases
  for (int trial = 0; trial < 100; trial++) {
    // random rotation
    Vec4d quat;
    quat[0] = uniform_dist.Get() * 2.0 - 1.0;
    quat[1] = uniform_dist.Get() * 2.0 - 1.0;
    quat[2] = uniform_dist.Get() * 2.0 - 1.0;
    quat[3] = uniform_dist.Get() * 2.0 - 1.0;
    Math::Quaternion::Normalize(&quat);
 
    // random position
    int id_facet = floor(uniform_dist.Get() * facets.size());
    auto vert_0 = vertices[facets[id_facet][0]];
    auto vert_1 = vertices[facets[id_facet][1]];
    auto vert_2 = vertices[facets[id_facet][2]];
 
    double u_vert = uniform_dist.Get();
    double v_vert = uniform_dist.Get() * (1 - u_vert);
    double w_vert = 1 - u_vert - v_vert;
 
    Vec3d pos;
    pos[0] = u_vert * vert_0[0] + v_vert * vert_1[0] + w_vert * vert_2[0];
    pos[1] = u_vert * vert_0[1] + v_vert * vert_1[1] + w_vert * vert_2[1];
    pos[2] = u_vert * vert_0[2] + v_vert * vert_1[2] + w_vert * vert_2[2];
    Math::Normalize(&pos);
 
    auto dist_pp = dist_min + uniform_dist.Get() * dist_range;
    pos[0] *= dist_pp;
    pos[1] *= dist_pp;
    pos[2] *= dist_pp;
 
    // apply to particle
    obj_p2.SetPosition(pos[0], pos[1], pos[2]);
    obj_p2.SetQuaternion(quat[0], quat[1], quat[2], quat[3]);
 
    // contact detection and resolution
    arma::mat input(7, 1, arma::fill::zeros);
    input(0, 0) = obj_p2.pos[0];
    input(1, 0) = obj_p2.pos[1];
    input(2, 0) = obj_p2.pos[2];
    input(3, 0) = obj_p2.quaternion[0] * Math::Sign(obj_p2.quaternion[0]);
    input(4, 0) = obj_p2.quaternion[1] * Math::Sign(obj_p2.quaternion[0]);
    input(5, 0) = obj_p2.quaternion[2] * Math::Sign(obj_p2.quaternion[0]);
    input(6, 0) = obj_p2.quaternion[3] * Math::Sign(obj_p2.quaternion[0]);
    auto output = classifier.Classify(input);
 
    cnt_solver.Init(&obj_p1, &obj_p2);
    auto cnt_flag_geo = cnt_solver.Detect();
    cout << "ann vs geometric: " << output(0) << ", " << cnt_flag_geo << endl;
 
    if (cnt_flag_geo) {
      auto cnt = ContactPP(&obj_p1, &obj_p2);
      cnt.SetCollisionModel(&cnt_model);
      cnt_solver.ResolveInit(&cnt, 1.0e-4);
      auto &cnt_geoms = cnt.collision_entries[0].cnt_geoms;
 
      // skip the contact if overlap is too large
      if (cnt_geoms.len_n > 0.05)
        continue;
 
      auto output = regressor.Predict(input);
      cout << ">> ann: " << output(0, 0) / 40.0 << ", " << output(1, 0) << ", "
           << output(2, 0) << ", " << output(3, 0) << ", " << output(4, 0)
           << ", " << output(5, 0) << ", " << output(6, 0) << endl;
 
      cout << ">> geo: " << cnt_geoms.len_n << ", " << cnt_geoms.dir_n[0]
           << ", " << cnt_geoms.dir_n[1] << ", " << cnt_geoms.dir_n[2] << ", "
           << cnt_geoms.pos[0] << ", " << cnt_geoms.pos[1] << ", "
           << cnt_geoms.pos[2] << endl;
    }
  }
}