freesurferformats (version 0.1.18)

write.fs.surface.ply: Write mesh to file in PLY format (.ply)

Description

The PLY format is a versatile ASCII format for storing meshes. Also known as Polygon File Format or Stanford Triangle Format.

Usage

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

Value

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

Arguments

filepath

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

vertex_coords

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

faces

m 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.

vertex_colors

optional, matrix of RGBA vertex colors, number of rows must be the same as for vertex_coords. Color values must be integers in range 0-255. Alternatively, a vector of *n* RGB color strings can be passed.

References

See http://paulbourke.net/dataformats/ply/ for the PLY format spec.

See Also

Other mesh export functions: write.fs.surface.obj(), write.fs.surface.off.ply2(), write.fs.surface.off(), write.fs.surface.ply2(), write.fs.surface()

Examples

if (FALSE) {
    # 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.ply(tempfile(fileext=".ply"), mesh$vertices, mesh$faces);

    # save a version with RGBA vertex colors
    vertex_colors = matrix(rep(82L, 5*4), ncol=4);
    write.fs.surface.ply(tempfile(fileext=".ply"), mesh$vertices,
     mesh$faces, vertex_colors=vertex_colors);
}