RenderLines2Tubes

% RenderLines2Tubes renders the input curve line cluster into a set of tubes.
% This program is built upon 'tubeplot' developed by Janus H. Wesenberg in 2016,
% but with the newly organized data structure, it allows to render multiple curves at a single run,
% which improves the effiency of the original project (tubeplot) significantly.
% Copyright (c) 2020, Junpeng Wang
% All rights reserved. Please read the "license.txt" for license terms.