ADD parametrisation.

Author: petrasvestartas

docs/examples/parametrisation.py

@@ -17,6 +17,7 @@
 # Least-squares conformal map
 # ==============================================================================
 
+#lscm_uv = igl.trimesh_harmonic(mesh.to_vertices_and_faces())
 lscm_uv = igl.trimesh_lscm(mesh.to_vertices_and_faces())
 
 for index, key in enumerate(mesh.vertices()):

src/compas.hpp

@@ -24,8 +24,8 @@
 
 // libigl includes
 #include <igl/boundary_loop.h>
+
 #include <igl/cotmatrix.h>
-#include <igl/massmatrix.h>
 #include <igl/invert_diag.h>
 
 #include <igl/gaussian_curvature.h>
@@ -44,6 +44,10 @@
 
 #include <igl/map_vertices_to_circle.h>
 #include <igl/harmonic.h>
+#include <igl/lscm.h>
+
+#include <igl/planarize_quad_mesh.h>
+
 #include <igl/doublearea.h>
 #include <igl/grad.h>
 #include <igl/per_vertex_normals.h>

src/compas_libigl/__init__.py

@@ -7,10 +7,10 @@
 from .intersections import intersection_ray_mesh, intersection_rays_mesh
 from .isolines import trimesh_isolines, groupsort_isolines
 from .massmatrix import trimesh_massmatrix
+from .parametrisation import trimesh_harmonic, trimesh_lscm
 
-# from .meshing import trimesh_remesh_along_isoline
-# from .parametrisation import trimesh_harmonic, trimesh_lscm
 # from .planarize import quadmesh_planarize
+# from .meshing import trimesh_remesh_along_isoline
 
 
 __author__ = ["tom van mele", "petras vestartas"]
@@ -89,9 +89,9 @@ def get_armadillo():
     "compas_libigl.intersections",
     "compas_libigl.isolines",
     "compas_libigl.massmatrix",
+    "compas_libigl.parametrisation",
+    "compas_libigl.planarize",
     # "compas_libigl.meshing",
-    # "compas_libigl.parametrisation",
-    # "compas_libigl.planarize",
 ]
 
 __all__ = [
@@ -113,8 +113,8 @@ def get_armadillo():
     "trimesh_isolines",
     "groupsort_isolines",
     "trimesh_massmatrix",
-    # "trimesh_remesh_along_isoline",
-    # "trimesh_harmonic",
-    # "trimesh_lscm",
+    "trimesh_harmonic",
+    "trimesh_lscm",
     # "quadmesh_planarize",
+    # "trimesh_remesh_along_isoline",
 ]

src/compas_libigl/parametrisation.py

@@ -0,0 +1,82 @@
+import numpy as np
+from compas.plugins import plugin
+
+from compas_libigl import _parametrisation
+
+
+@plugin(category="trimesh")
+def trimesh_harmonic(M):
+    """Compute the harmonic parametrisation of a triangle mesh within a fixed circular boundary.
+
+    Parameters
+    ----------
+    M : tuple
+        A mesh represented by a list of vertices and a list of faces
+        or by a COMPAS mesh object.
+
+    Returns
+    -------
+    array
+        The u, v parameters per vertex.
+
+    Examples
+    --------
+    >>> import compas_libigl as igl
+    >>> from compas.datastructures import Mesh
+    >>> mesh = Mesh.from_off(igl.get("camelhead.off"))
+    >>> mesh_uv = mesh.copy()
+    >>> mesh_uv.vertices_attribute("z", 0)
+    >>> M = mesh.to_vertices_and_faces()
+    >>> uv = igl.trimesh_harmonic(M)
+    >>> for key in mesh.vertices():
+    ...     mesh_uv.vertex_attributes(key, "xy", uv[key])
+    >>>
+
+    Notes
+    -----
+    ``camelhead.off`` can be downloaded from https://raw.githubusercontent.com/libigl/libigl-tutorial-data/master/camelhead.off
+
+    """
+    V, F = M
+    V = np.asarray(V, dtype=np.float64)
+    F = np.asarray(F, dtype=np.int32)
+    return _parametrisation.harmonic(V, F)
+
+
+@plugin(category="trimesh")
+def trimesh_lscm(M):
+    """Compute the least squares conformal map of a triangle mesh.
+
+    Parameters
+    ----------
+    M : tuple
+        A mesh represented by a list of vertices and a list of faces
+        or by a COMPAS mesh object.
+
+    Returns
+    -------
+    array
+        The u, v parameters per vertex.
+
+    Examples
+    --------
+    >>> import compas_libigl as igl
+    >>> from compas.datastructures import Mesh
+    >>> mesh = Mesh.from_off(igl.get("camelhead.off"))
+    >>> mesh_uv = mesh.copy()
+    >>> mesh_uv.vertices_attribute("z", 0)
+    >>> M = mesh.to_vertices_and_faces()
+    >>> uv = igl.trimesh_lscm(M)
+    >>> for key in mesh.vertices():
+    ...     mesh_uv.vertex_attributes(key, "xy", uv[key])
+    >>>
+
+    Notes
+    -----
+    ``camelhead.off`` can be downloaded from https://raw.githubusercontent.com/libigl/libigl-tutorial-data/master/camelhead.off
+
+    """
+    V, F = M
+    V = np.asarray(V, dtype=np.float64)
+    F = np.asarray(F, dtype=np.int32)
+    return _parametrisation.lscm(V, F)

src/parametrisation.cpp

@@ -1,13 +1,66 @@
 #include "parametrisation.hpp"
 
-void function(const compas::RowMatrixXd& V, const compas::RowMatrixXi& F) {}
+
+Eigen::MatrixXd
+harmonic(
+    const compas::RowMatrixXd& V,
+    const compas::RowMatrixXi& F)
+{
+    Eigen::MatrixXd V_uv;
+
+    // Find the open boundary
+    Eigen::VectorXi B;
+    igl::boundary_loop(F, B);
+
+    // Map the boundary to a circle, preserving edge proportions
+    Eigen::MatrixXd B_uv;
+    igl::map_vertices_to_circle(V, B, B_uv);
+
+    // Harmonic parametrization for the internal vertices
+    igl::harmonic(V, F, B, B_uv, 1, V_uv);
+
+    return V_uv;
+}
+
+
+Eigen::MatrixXd
+lscm(
+    const compas::RowMatrixXd& V,
+    const compas::RowMatrixXi& F)
+{
+    Eigen::MatrixXd V_uv;
+
+    // Find the open boundary
+    Eigen::VectorXi B;
+    igl::boundary_loop(F, B);
+
+    // Fix two points on the boundary
+    Eigen::VectorXi fixed(2, 1);
+    fixed(0) = B(0);
+    fixed(1) = B(B.size() / 2);
+
+    Eigen::MatrixXd fixed_uv(2, 2);
+    fixed_uv << 0, 0, 1, 0;
+
+    // LSCM parametrization
+    igl::lscm(V, F, fixed, fixed_uv, V_uv);
+
+    return V_uv;
+}
 
 NB_MODULE(_parametrisation, m) {
 
     m.def(
-        "function_name",
-        &function,
-        "Description.",
+        "harmonic",
+        &harmonic,
+        "Compute the harmonic parametrization of a triangle mesh.",
+        "V"_a,
+        "F"_a);
+
+    m.def(
+        "lscm",
+        &lscm,
+        "Compute the least-squares conformal map of a triangle mesh.",
         "V"_a,
         "F"_a);
 }