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read_mesh

read_mesh(file, fmt=None, return_UV=False, return_N=False, return_C=False, reader=None, merge_stl=True)

Reads a mesh from file.

If you have the approproate C++ extensions installed, this will use a fast C++-based reader. If you do not, this will use a slow python reader.

Currently only supports triangle meshes.

Parameters:

Name Type Description Default
file string

the path the mesh will be read from

 required
fmt string, optional (default: None)

The file format of the mesh to open. If None, try to guess the format from the file extension. Supported formats: obj, stl

 None
return_UV bool, optional (default: None)

Try reading texture coordinates, if they are present and the file format supports it. Only supported for OBJ files.

 False
return_N bool, optional (default: None)

Try reading normal coordinates, if they are present and the file format supports it. Only supported for OBJ and PLY files.

 False
return_C bool, optional (default: None)

Try reading color RGBA values, if they are present and the file format supports it. Only supported for PLY files.

 False
reader string, optional (default: None)

Which reader engine to use. None, 'C++' or 'Python'. If None, will use C++ if available, and else Python.

 None
merge_stl bool, optional (default: True)

If True, will merge the disconnected triangle STL file by removing duplicate vertices.

 True

Returns:

Name Type Description
V (n,3) numpy array

vertex list of a triangle mesh
F (m,3) numpy int array

face index list of a triangle mesh (into V)
UV (n_uv,2) numpy array, if requested

vertex list for texture coordinates
Ft (m,3) numpy int array, if requested

face index list for texture coordinates (into UV)
N (n_n,3) numpy array, if requested

vertex list for normal coordinates
Fn (m,3) numpy int array, if requested

face index list for normal coordinates (into N)
C (n,4) or (m,4) numpy int array, if requested

per-vertex or per-face colors

Examples:

# Read a mesh in OBJ format
v,f = gpytoolbox.read_mesh('mesh.obj')

# Read a mesh in STL format
v,f = gpytoolbox.read_mesh('mesh.stl',merge_stl=False)
# This mesh will just be a set of disconnected triangles, so functions like boundary_vertices will just return every vertex
assert len(gpytoolbox.boundary_vertices(f))==v.shape[0]
# Read a mesh in STL format, and merge the disconnected triangles
v,f = gpytoolbox.read_mesh('mesh.stl',merge_stl=True)
# Now the mesh is a single connected mesh, so boundary_vertices will return the correct result
assert len(gpytoolbox.boundary_vertices(f))<v.shape[0]
Source code in src/gpytoolbox/read_mesh.py 
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def read_mesh(file,
    fmt=None,
    return_UV=False,
    return_N=False,
    return_C=False,
    reader=None,
    merge_stl=True):
    """Reads a mesh from file.

    If you have the approproate C++ extensions installed, this will use a fast
    C++-based reader. If you do not, this will use a slow python reader.

    Currently only supports triangle meshes.

    Parameters
    -------
    file : string
        the path the mesh will be read from
    fmt : string, optional (default: None)
        The file format of the mesh to open.
        If None, try to guess the format from the file extension.
        Supported formats: obj, stl
    return_UV : bool, optional (default: None)
        Try reading texture coordinates, if they are present and the file
        format supports it. Only supported for OBJ files.
    return_N : bool, optional (default: None)
        Try reading normal coordinates, if they are present and the file format
        supports it. Only supported for OBJ and PLY files.
    return_C : bool, optional (default: None)
        Try reading color RGBA values, if they are present and the file format
        supports it. Only supported for PLY files.
    reader : string, optional (default: None)
        Which reader engine to use. None, 'C++' or 'Python'.
        If None, will use C++ if available, and else Python.
    merge_stl : bool, optional (default: True)
        If True, will merge the disconnected triangle STL file by removing duplicate vertices.

    Returns
    ----------
    V : (n,3) numpy array
        vertex list of a triangle mesh
    F : (m,3) numpy int array
        face index list of a triangle mesh (into V)
    UV : (n_uv,2) numpy array, if requested
        vertex list for texture coordinates
    Ft : (m,3) numpy int array, if requested
        face index list for texture coordinates (into UV)
    N : (n_n,3) numpy array, if requested
        vertex list for normal coordinates
    Fn : (m,3) numpy int array, if requested
        face index list for normal coordinates (into N)
    C : (n,4) or (m,4) numpy int array, if requested
        per-vertex or per-face colors

    Examples
    --------
    ```python
    # Read a mesh in OBJ format
    v,f = gpytoolbox.read_mesh('mesh.obj')
    ```

    ```python
    # Read a mesh in STL format
    v,f = gpytoolbox.read_mesh('mesh.stl',merge_stl=False)
    # This mesh will just be a set of disconnected triangles, so functions like boundary_vertices will just return every vertex
    assert len(gpytoolbox.boundary_vertices(f))==v.shape[0]
    # Read a mesh in STL format, and merge the disconnected triangles
    v,f = gpytoolbox.read_mesh('mesh.stl',merge_stl=True)
    # Now the mesh is a single connected mesh, so boundary_vertices will return the correct result
    assert len(gpytoolbox.boundary_vertices(f))<v.shape[0]
    ```

    """

    # Detect format if it has not been specified
    if fmt is None:
        _, fmt = os.path.splitext(file)
    fmt = fmt[1:].lower()

    # Call appropriate helper function to read mesh
    if fmt=='obj':
        V,F,UV,Ft,N,Fn = _read_obj(file,return_UV,return_N,reader)
    elif fmt=='stl':
        V,F = _read_stl(file,merge_stl)
    elif fmt=='ply':
        V,F,N,C = _read_ply(file)
        if return_N:
            Fn = None
    else:
        assert False, "Mesh format not supported."

    # Arrange variables for output
    if return_UV and return_N:
        return V,F,UV,Ft,N,Fn
    if return_UV:
        return V,F,UV,Ft
    if (return_N and return_C):
        return V,F,N,Fn,C
    if return_N:
        return V,F,N,Fn
    if return_C:
        return V,F,C
    return V,F