Least-Square Conformal Maps

Example

import mouette as M

mesh = M.mesh.load("path/to/mesh")
lscm = M.parametrization.LSCM(mesh, [options])
lscm.run()

See https://github.com/GCoiffier/mouette/blob/main/examples/parametrization/lscm.py

LSCM(mesh, verbose=False, **kwargs)

Bases: BaseParametrization

Least-Square Conformal Map algorithm for computing a parametrization of a mesh. /!\ The mesh should have the topology of a disk. Computed UVs are stored in the self.uvs container

References

• [1] Least Squares Conformal Maps for Automatic Texture Atlas Generation, Levy et al. (2002)
• [2] Spectral Conformal Parameterization, Mullen et al. (2008)
• [3] Intrinsic Parameterizations of Surface Meshes, Desbrun et al. (2002)

Parameters:

Name	Type	Description	Default
mesh	SurfaceMesh	the supporting mesh. Should be a surface with disk topology.	required
verbose	bool	verbose mode. Defaults to False.	False

Other Parameters:

Name	Type	Description
eigen	bool	whether to solve a linear system with two fixed points or use an eigen solver. Defaults to True
save_on_corners	bool	whether to store the results on face corners or vertices. Defaults to True
solver_verbose	bool	verbose level. Defaults to False.

flat_mesh: SurfaceMesh property

A flat representation of the mesh where uv-coordinates are copied to xy.

Returns:

Name	Type	Description
SurfaceMesh	SurfaceMesh	the flat mesh

run()

Calls the solver on the LSCM system.

Raises:

Type	Description
Exception	fails if the mesh is not a topological disk

PointCloud(data=None)

Bases: Mesh

A data structure for representing point clouds

Attributes:

Name	Type	Description
vertices	DataContainer	the container for all vertices
__str__	str	Representation of the object and its elements as a string.

id_vertices property

Shortcut for range(len(self.vertices))

append(x)

Shortcut for self.vertices.append(x), since we can only append elements in the 'vertices' container

PolyLine(data=None)

Bases: Mesh

A data structure for representing polylines.

Attributes:

Name	Type	Description
vertices	DataContainer	the container for all vertices
edges	DataContainer	the container for all edges
__str__		Representation of the object and its elements as a string.

id_edges property

Shortcut for range(len(self.edges))

id_vertices property

Shortcut for range(len(self.vertices))

SurfaceMesh(data=None)

Bases: Mesh

A data structure for representing polygonal surfaces.

Attributes:

Name	Type	Description
vertices	DataContainer	the container for all vertices
edges	DataContainer	the container for all edges
faces	DataContainer	the container for all faces
face_corners	DataContainer	the container for all corner of faces
boundary_edges	list	list of all edge indices on the boundary
interior_edges	list	list of all interior edge indices (all edges \ boundary_edges)
boundary_vertices	list	list of all vertex indices on the boundary
interior_vertices	list	list of all interior verticex indices (all vertices \ boundary_vertices)
connectivity	_SurfaceConnectivity	the connectivity utility class

id_corners property

Shortcut for range(len(self.face_corners))

id_edges property

Shortcut for range(len(self.edges))

id_faces property

Shortcut for range(len(self.faces))

id_vertices property

Shortcut for range(len(self.vertices))

clear_boundary_data()

Clear all boundary data. Next call to a boundary/interior container or method will recompute everything

is_edge_on_border(u, v)

whether edge (u,v) is a boundary edge or not

Parameters:

Name	Type	Description	Default
u	int	vertex id	required
v	int	vertex id	required

Returns:

Name	Type	Description
bool	bool	whether edge (u,v) is a boundary edge or not. Returns False if (u,v) is not a valid edge.

is_quad()

Returns:

Name	Type	Description
bool	bool	True if the mesh is quadrangular (all faces are quad)

is_triangular()

Returns:

Name	Type	Description
bool	bool	True if the mesh is triangular (all faces are triangles)

is_vertex_on_border(u)

whether vertex u is a boundary vertex or not.

Parameters:

Name	Type	Description	Default
u	int	vertex id	required

Returns:

Name	Type	Description
bool	bool	whether vertex u is a boundary vertex or not.

ith_vertex_of_face(fid, i)

helper function to get the i-th vertex of a face, i.e. self.faces[fid][i]

Parameters:

Name	Type	Description	Default
fid	int	face id	required
i	int	vertex id in face. Should be 0 <= vid < len(face)	required

Returns:

Name	Type	Description
int	int	the id of the i-th vertex in face fid (self.faces[fid][i])

pt_of_face(fid)

point coordinates of vertices of face fid

Parameters:

Name	Type	Description	Default
fid	int	face id	required

Returns:

Name	Type	Description
Iterable		iterator of Vec objects representing point coordinates of vertices

VolumeMesh(data=None)

Bases: Mesh

id_cells property

Shortcut for range(len(self.cells))

id_corners property

Shortcut for range(len(self.face_corners))

id_edges property

Shortcut for range(len(self.edges))

id_faces property

Shortcut for range(len(self.faces))

id_vertices property

Shortcut for range(len(self.vertices))

is_edge_on_border(*args)

Simple test to determine if a given edge is on the boundary of the mesh.

Returns:

Name	Type	Description
bool	bool	Returns True if the given edge is on the boundary of the mesh.

is_face_on_border(*args)

Simple test to determine if a given face is on the boundary of the mesh.

Returns:

Name	Type	Description
bool	bool	Returns True is the given face exists and is on the boundary of the mesh

is_tetrahedral()

Returns:

Name	Type	Description
bool	bool	True if the mesh is tetrahedral (all cells are tetrahedra)