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write_ply

write_ply(filename, vertices, faces=None, colors=None, cmap='BuGn')

Store triangle mesh into .ply file format

Writes a triangle mesh (optionally with per-vertex colors) into the ply file format, in a way consistent with, e.g., importing to Blender.

Parameters:

Name Type Description Default
filename str

Name of the file ending in ".ply" to which to write the mesh

 required
vertices numpy double array

Matrix of mesh vertex coordinates

 required
faces numpy int array, optional (default None)

Matrix of triangle face indices into vertices. If none, only the vertices will be written (e.g., a point cloud)

 None
colors numpy double array, optional (default None)

Array of per-vertex colors. It can be a matrix of per-row RGB values, or a vector of scalar values that gets transformed by a colormap.

 None
cmap str, optional (default 'BuGn')

Name of colormap used to transform the color values if they are a vector of scalar function values (if colors is a matrix of RGB values, this parameter will not be used). Should be a valid input to colormap.

 'BuGn'

See Also

write_mesh, colormap.

Notes

This function is not optimized and covers the very specific funcionality of saving a mesh with per-vertex coloring that can be imported into Blender or other software. If you wish to write a mesh for any other purpose, we strongly recommend you use write_mesh instead.

Examples:

TODO

Source code in src/gpytoolbox/write_ply.py 
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def write_ply(filename,vertices,faces=None,colors=None,cmap='BuGn'):
    """Store triangle mesh into .ply file format

    Writes a triangle mesh (optionally with per-vertex colors) into the ply file format, in a way consistent with, e.g., importing to Blender.

    Parameters
    ----------
    filename : str
        Name of the file ending in ".ply" to which to write the mesh
    vertices : numpy double array
        Matrix of mesh vertex coordinates
    faces : numpy int array, optional (default None)
        Matrix of triangle face indices into vertices. If none, only the vertices will be written (e.g., a point cloud)
    colors : numpy double array, optional (default None)
        Array of per-vertex colors. It can be a matrix of per-row RGB values, or a vector of scalar values that gets transformed by a colormap.
    cmap : str, optional (default 'BuGn')
        Name of colormap used to transform the color values if they are a vector of scalar function values (if colors is a matrix of RGB values, this parameter will not be used). Should be a valid input to `colormap`.

    See Also
    --------
    write_mesh, colormap.

    Notes
    -----
    This function is not optimized and covers the very specific funcionality of saving a mesh with per-vertex coloring that can be imported into Blender or other software. If you wish to write a mesh for any other purpose, we strongly recommend you use write_mesh instead.

    Examples
    --------
    TODO
    """

    vertices = vertices.astype(float)
    f = open(filename,"w")
    f.write("ply\nformat {} 1.0\n".format('ascii'))
    f.write("element vertex {}\n".format(vertices.shape[0]))
    f.write("property double x\n")
    f.write("property double y\n")
    f.write("property double z\n")
    if (colors is not None):
        f.write("property uchar red\n")
        f.write("property uchar green\n")
        f.write("property uchar blue\n")
        f.write("property uchar alpha\n")
    if (faces is not None):
        f.write("element face {}\n".format(faces.shape[0]))
    else:
        f.write("element face 0\n")
    f.write("property list int int vertex_indices\n")
    f.write("end_header\n")
    # write_vert_str = "{} {} {}\n" * vertices.shape[0]
    # f.write(write_vert_str.format(tuple(np.reshape(vertices,(-1,1)))))
    # This for loop should be vectorized
    if (colors is None):
        for i in range(vertices.shape[0]):
            f.write("{} {} {}\n".format(vertices[i,0],vertices[i,1],vertices[i,2]))
    else:
        if (colors.ndim==1 or colors.shape[1]==1): # color is scalar values
            C = apply_colormap(colormap(cmap, 200), colors)
        else:
            if np.max(colors)<=1:
                C = np.round(colors*255)
            else:
                C = colors
        # This should be vectorized
        for i in range(vertices.shape[0]):
            f.write("{} {} {} {} {} {} 255\n".format(vertices[i,0],vertices[i,1],vertices[i,2],int(C[i,0]),int(C[i,1]),int(C[i,2])))
    # This should be vectorized
    if (faces is not None):
        for i in range(faces.shape[0]):
            f.write("3 {} {} {}\n".format(faces[i,0],faces[i,1],faces[i,2]))
    f.close()