The wavefront object format is a simply ASCII format for storing meshes.

write.fs.surface.obj(filepath, vertex_coords, faces, vertex_colors = NULL)



string. Full path to the output surface file, should end with '.vtk', but that is not enforced.


n x 3 matrix of doubles. Each row defined the x,y,z coords for a vertex.


n x 3 matrix of integers. Each row defined the 3 vertex indices that make up the face. WARNING: Vertex indices should be given in R-style, i.e., the index of the first vertex is 1. However, they will be written in FreeSurfer style, i.e., all indices will have 1 substracted, so that the index of the first vertex will be zero.


vector of vertex colors. Will be written after the x, y, z coords on vertex lines. WARNING: This is NOT part of the official OBJ standard, and may not work with other software and even break some parsers.


string the format that was written. One of "tris" or "quads". Currently only triangular meshes are supported, so always 'tris'.


Do not confuse the Wavefront object file format (.obj) with the OFF format (.off), they are not identical.

See also


# \donttest{
    # Read a surface from a file:
    surface_file = system.file("extdata", "lh.tinysurface",
     package = "freesurferformats", mustWork = TRUE);
    mesh = read.fs.surface(surface_file);

    # Now save it:
    write.fs.surface.obj(tempfile(fileext=".obj"), mesh$vertices, mesh$faces);
# }