added 507

Former-commit-id: fc093eb7ee80fbf1c6dfc6def8f4a6efa3763678

python/507_PolyVectorField.py

@@ -0,0 +1,126 @@
+import igl
+import random
+from math import cos,sin,pi
+
+# Input mesh
+V = igl.eigen.MatrixXd()
+F = igl.eigen.MatrixXi()
+
+# Per face bases
+B1 = igl.eigen.MatrixXd()
+B2 = igl.eigen.MatrixXd()
+B3 = igl.eigen.MatrixXd()
+
+# Face barycenters
+B = igl.eigen.MatrixXd()
+
+# Scale for visualizing the fields
+global_scale = 1
+
+# Random length factor
+rand_factor = 5
+
+samples = igl.eigen.MatrixXi()
+
+def readSamples(fname):
+    samples = igl.eigen.MatrixXi()
+    numSamples = 0
+
+    fp = open(fname, 'r')
+
+    numSamples = int(fp.readline())
+
+    samples.resize(numSamples,1)
+
+    for i in range(0,numSamples):
+        samples[i] = int(fp.readline())
+
+    fp.close()
+
+    return samples
+
+# Create a random set of tangent vectors
+def random_constraints(b1, b2, n):
+
+    r = igl.eigen.MatrixXd(1,n*3)
+
+    for i in range(0,n):
+        a = random.random()*2*pi
+        s = 1 + random.random() * rand_factor
+        t = s * (cos(a) * b1 + sin(a) * b2)
+        r.setBlock(0,i*3,1,3,t)
+
+    return r
+
+def key_down(viewer, key, modifier):
+    if key < ord('1') or key > ord('8'):
+        return False
+
+    viewer.data.lines.resize(0,9)
+
+    num = key  - ord('0')
+
+    # Interpolate
+    print("Interpolating " + repr(num * 2) + "-PolyVector field")
+
+    b = igl.eigen.MatrixXi([[4550, 2321, 5413, 5350]]).transpose()
+
+    bc = igl.eigen.MatrixXd(b.size(),num*3)
+
+    for i in range(0,b.size()):
+        t = random_constraints(B1.row(b[i]),B2.row(b[i]),num)
+        bc.setRow(i,t)
+
+    # Interpolated PolyVector field
+    pvf = igl.eigen.MatrixXd()
+    igl.n_polyvector(V, F, b, bc, pvf)
+
+    # Highlight in red the constrained faces
+    C = igl.eigen.MatrixXd.Constant(F.rows(),3,1)
+
+    for i in range(0,b.size()):
+        C.setRow(b[i],igl.eigen.MatrixXd([[1, 0, 0]]))
+    viewer.data.set_colors(C)
+
+    for n in range(0,num):
+        VF = igl.eigen.MatrixXd.Zero(F.rows(),3)
+
+        for i in range(0,b.size()):
+            VF.setRow(b[i],bc.block(i,n*3,1,3))
+
+        for i in range(0,samples.rows()):
+            VF.setRow(samples[i],pvf.block(samples[i],n*3,1,3))
+
+        c = VF.rowwiseNorm()
+
+        C2 = igl.eigen.MatrixXd()
+        igl.jet(c,1,1+rand_factor,C2)
+        viewer.data.add_edges(B - global_scale*VF, B + global_scale*VF , C2)
+
+    return False
+
+
+# Load a mesh in OBJ format
+igl.readOBJ("../tutorial/shared/lilium.obj", V, F)
+samples = readSamples("../tutorial/shared/lilium.samples.0.2")
+
+# Compute local basis for faces
+igl.local_basis(V,F,B1,B2,B3)
+
+# Compute face barycenters
+igl.barycenter(V, F, B)
+
+# Compute scale for visualizing fields
+global_scale = 0.2*igl.avg_edge_length(V, F)
+
+# Make the example deterministic
+random.seed(0)
+
+viewer = igl.viewer.Viewer()
+viewer.data.set_mesh(V, F)
+viewer.callback_key_down = key_down
+viewer.core.show_lines = False
+
+key_down(viewer,ord('2'),0)
+
+viewer.launch()

python/py_igl.cpp

@@ -47,6 +47,7 @@
 #include <igl/find_cross_field_singularities.h>
 #include <igl/cut_mesh_from_singularities.h>
 #include <igl/comb_frame_field.h>
+#include <igl/n_polyvector.h>
 
 
 void python_export_igl(py::module &m)
@@ -96,5 +97,6 @@ void python_export_igl(py::module &m)
 #include "py_igl/py_find_cross_field_singularities.cpp"
 #include "py_igl/py_cut_mesh_from_singularities.cpp"
 #include "py_igl/py_comb_frame_field.cpp"
+#include "py_igl/py_n_polyvector.cpp"
 
 }

python/py_igl/py_n_polyvector.cpp

@@ -0,0 +1,19 @@
+m.def("n_polyvector", []
+(
+  const Eigen::MatrixXd& V,
+  const Eigen::MatrixXi& F,
+  const Eigen::MatrixXi& b,
+  const Eigen::MatrixXd& bc,
+  Eigen::MatrixXd &output
+)
+{
+  assert_is_VectorX("b",b);
+
+  Eigen::VectorXi bt;
+  if (b.size() != 0)
+    bt = b;
+
+  igl::n_polyvector(V,F,bt,bc,output);
+
+}, __doc_igl_n_polyvector,
+py::arg("V"), py::arg("F"), py::arg("b"), py::arg("bc"), py::arg("output"));