* adding streamline code and tutorial

* adding python bindings for streamline and python tutorial Former-commit-id: 9abb24e0bc
2016-08-11 10:37:34 -04:00
parent a0664b0a3d
commit e9db1095fd
14 changed files with 742 additions and 0 deletions
@@ -0,0 +1,165 @@
+#include <igl/barycenter.h>
+#include <igl/edge_topology.h>
+#include <igl/local_basis.h>
+#include <igl/parula.h>
+#include <igl/per_face_normals.h>
+#include <igl/per_vertex_normals.h>
+#include <igl/polyvector_field_matchings.h>
+#include <igl/read_triangle_mesh.h>
+#include <igl/readOFF.h>
+#include <igl/slice.h>
+#include <igl/sort_vectors_ccw.h>
+#include <igl/streamlines.h>
+#include <igl/triangle_triangle_adjacency.h>
+#include <igl/copyleft/comiso/nrosy.h>
+#include <igl/viewer/Viewer.h>
+
+#include <cstdlib>
+#include <iostream>
+#include <vector>
+#include <fstream>
+
+
+// Mesh
+Eigen::MatrixXd V;
+Eigen::MatrixXi F;
+
+igl::StreamlineData data;
+igl::StreamlineState state;
+
+int degree;         // degree of the vector field
+int half_degree;    // degree/2 if treat_as_symmetric
+bool treat_as_symmetric = true;
+
+int anim_t = 0;
+int anim_t_dir = 1;
+
+
+void representative_to_nrosy(
+        const Eigen::MatrixXd &V,
+        const Eigen::MatrixXi &F,
+        const Eigen::MatrixXd &R,
+        const int N,
+        Eigen::MatrixXd &Y)
+{
+    using namespace Eigen;
+    using namespace std;
+    MatrixXd B1, B2, B3;
+
+    igl::local_basis(V, F, B1, B2, B3);
+
+    Y.resize(F.rows(), 3 * N);
+    for (unsigned i = 0; i < F.rows(); ++i)
+    {
+        double x = R.row(i) * B1.row(i).transpose();
+        double y = R.row(i) * B2.row(i).transpose();
+        double angle = atan2(y, x);
+
+        for (unsigned j = 0; j < N; ++j)
+        {
+            double anglej = angle + M_PI * double(j) / double(N);
+            double xj = cos(anglej);
+            double yj = sin(anglej);
+            Y.block(i, j * 3, 1, 3) = xj * B1.row(i) + yj * B2.row(i);
+        }
+    }
+}
+
+bool pre_draw(igl::viewer::Viewer &viewer)
+{
+    using namespace Eigen;
+    using namespace std;
+
+    if (!viewer.core.is_animating)
+        return false;
+
+    igl::streamlines_next(V, F, data, state);
+    Eigen::RowVector3d color = Eigen::RowVector3d::Zero();
+    double value = ((anim_t) % 100) / 100.;
+
+    if (value > 0.5)
+        value = 1 - value;
+    value = value / 0.5;
+    igl::parula(value, color[0], color[1], color[2]);
+
+    viewer.data.add_edges(state.start_point, state.end_point, color);
+
+    anim_t += anim_t_dir;
+
+    return false;
+}
+
+bool key_down(igl::viewer::Viewer &viewer, unsigned char key, int modifier)
+{
+    if (key == ' ')
+    {
+        viewer.core.is_animating = !viewer.core.is_animating;
+        return true;
+    }
+    return false;
+}
+
+int main(int argc, char *argv[])
+{
+    using namespace Eigen;
+    using namespace std;
+
+
+    // Load a mesh in OFF format
+    igl::readOFF(TUTORIAL_SHARED_PATH "/bumpy.off", V, F);
+    // Create a Vector Field
+    Eigen::VectorXi b;
+    Eigen::MatrixXd bc;
+    Eigen::VectorXd S; // unused
+
+    b.resize(1);
+    b << 0;
+    bc.resize(1, 3);
+    bc << 1, 1, 1;
+
+    half_degree = 3;
+    treat_as_symmetric = true;
+
+    Eigen::MatrixXd temp_field, temp_field2;
+    igl::copyleft::comiso::nrosy(V, F, b, bc, VectorXi(), VectorXd(), MatrixXd(), 1, 0.5, temp_field, S);
+    representative_to_nrosy(V, F, temp_field, half_degree, temp_field2);
+
+
+    igl::streamlines_init(V, F, temp_field2, treat_as_symmetric, data, state);
+
+
+    // Viewer Settings
+    igl::viewer::Viewer viewer;
+    viewer.data.set_mesh(V, F);
+    viewer.callback_pre_draw = &pre_draw;
+    viewer.callback_key_down = &key_down;
+
+    viewer.core.show_lines = false;
+
+    viewer.core.is_animating = false;
+    viewer.core.animation_max_fps = 30.;
+
+    // Paint mesh grayish
+    Eigen::MatrixXd C;
+    C.setConstant(viewer.data.V.rows(), 3, .9);
+    viewer.data.set_colors(C);
+
+
+    // Draw vector field on sample points
+    igl::StreamlineState state0;
+    state0 = state;
+    igl::streamlines_next(V, F, data, state0);
+    Eigen::MatrixXd v = state0.end_point - state0.start_point;
+    v.rowwise().normalize();
+
+    viewer.data.add_edges(state0.start_point,
+                          state0.start_point + 0.059 * v,
+                          Eigen::RowVector3d::Constant(1.0f));
+
+    cout <<
+    "Press [space] to toggle animation" << endl;
+    viewer.launch();
+}
+
+
+