Spline Exporter Script

# coding: utf-8
# Copyright (C) 2012  Niklas Rosenstein
#
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation; either version 3 of the License, or (at your option) any later
# version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, see <http://www.gnu.org/licenses/>.

import os
import c4d
import string

def write_vector(vector, file, prependix='', appendix='', delimiter=',',
                 precision=2):
    """ Writes the passed `c4d.Vector` instance *vector* to the file-like
        object *file*. *prependix* and *appendix* are optional strings that
        will enclose the written vector. The vectors float-values will be
        separated by *delimiter*. The float-value precision is given with the
        integer value *precision*. """
    precision = int(precision)
    format = delimiter.join('%%.%df' % precision for i in xrange(3))
    file.write(prependix + (format % (vector.x, vector.y, vector.z)) + appendix)

def write_spline(spline, file, precision=2):
    """ Writes the passed `c4d.SplineObject` *spline* in ASCII format to
        *file*. """

    if not isinstance(spline, c4d.SplineObject):
        raise TypeError("Expected SplineObject.")

    type = spline.GetInterpolationType()
    segment_count = spline.GetSegmentCount()
    type_ascii = { c4d.SPLINETYPE_BEZIER:  'bezier',
                   c4d.SPLINETYPE_LINEAR:  'linear',
                   c4d.SPLINETYPE_CUBIC:   'cubic',
                   c4d.SPLINETYPE_AKIMA:   'akima',
                   c4d.SPLINETYPE_BSPLINE: 'bspline', }.get(type, None)
    if type_ascii is None:
        raise ValueError('spline.GetInterpolationType() returned invalid type.')

    if segment_count > 0:
        segments = [spline.GetSegment(i) for i in xrange(segment_count)]
    else:
        segments = [{'cnt': op.GetPointCount(), 'closed': spline.IsClosed()}]
        segment_count = 1

    # write spline information
    file.write('spline %s, %d segments\n' % (type_ascii, segment_count))

    segment_offset = 0
    for segment in segments:

        # write segment information
        file.write('%d points, ' % segment['cnt'])
        if segment['closed']:
            file.write('closed\n')
        else:
            file.write('open\n')

        # write segment vectors
        for index in xrange(segment['cnt']):
            index += segment_offset
            point = spline.GetPoint(index)
            write_vector(point, file, precision=precision)

            # write tangent information if the spline is a Bezièr-Spline.
            if type == c4d.SPLINETYPE_BEZIER:
                tangents = op.GetTangent(index)
                tl, tr = tangents['vl'], tangents['vr']

                write_vector(tl, file, precision=precision, prependix=',',
                             appendix=',')
                write_vector(tl, file, precision=precision)

            file.write('\n')

        segment_offset += segment['cnt']

def main():
    if not op:
        return
    if not isinstance(op, c4d.SplineObject):
        c4d.gui.MessageDialog("select a spline object.")
        return

    path = c4d.storage.SaveDialog()
    if os.path.isdir(path):
        c4d.gui.MessageDialog("the seleected path is a directory.")
        return

    with open(path, 'w') as fl:
        write_spline(op, fl)

if __name__ == "__main__":
    main()