--- /dev/null
+## Copyright (C) 2009-2012 Martin Helm
+##
+## This file is part of Octave.
+##
+## Octave 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.
+##
+## Octave 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 Octave; see the file COPYING. If not, see
+## <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {[@var{fv}] =} isosurface (@var{val}, @var{iso})
+## @deftypefnx {Function File} {[@var{fv}] =} isosurface (@var{x}, @var{y}, @var{z}, @var{val}, @var{iso})
+## @deftypefnx {Function File} {[@var{fv}] =} isosurface (@dots{}, "noshare", "verbose")
+## @deftypefnx {Function File} {[@var{fvc}] =} isosurface (@dots{}, @var{col})
+## @deftypefnx {Function File} {[@var{f}, @var{v}] =} isosurface (@var{x}, @var{y}, @var{z}, @var{val}, @var{iso})
+## @deftypefnx {Function File} {[@var{f}, @var{v}, @var{c}] =} isosurface (@var{x}, @var{y}, @var{z}, @var{val}, @var{iso}, @var{col})
+## @deftypefnx {Function File} {} isosurface (@var{x}, @var{y}, @var{z}, @var{val}, @var{iso}, @var{col}, @var{opt})
+##
+## If called with one output argument and the first input argument
+## @var{val} is a three-dimensional array that contains the data of an
+## isosurface geometry and the second input argument @var{iso} keeps the
+## isovalue as a scalar value then return a structure array @var{fv}
+## that contains the fields @var{Faces} and @var{Vertices} at computed
+## points @command{[x, y, z] = meshgrid (1:l, 1:m, 1:n)}. The output
+## argument @var{fv} can directly be taken as an input argument for the
+## @command{patch} function.
+##
+## If called with further input arguments @var{x}, @var{y} and @var{z}
+## which are three--dimensional arrays with the same size than @var{val}
+## then the volume data is taken at those given points.
+##
+## The string input argument "noshare" is only for compatibility and
+## has no effect. If given the string input argument
+## "verbose" then print messages to the command line interface about the
+## current progress.
+##
+## If called with the input argument @var{col} which is a
+## three-dimensional array of the same size than @var{val} then take
+## those values for the interpolation of coloring the isosurface
+## geometry. Add the field @var{FaceVertexCData} to the structure
+## array @var{fv}.
+##
+## If called with two or three output arguments then return the
+## information about the faces @var{f}, vertices @var{v} and color data
+## @var{c} as seperate arrays instead of a single structure array.
+##
+## If called with no output argument then directly process the
+## isosurface geometry with the @command{patch} command.
+##
+## For example,
+##
+## @example
+## @group
+## [x, y, z] = meshgrid (1:5, 1:5, 1:5);
+## val = rand (5, 5, 5);
+## isosurface (x, y, z, val, .5);
+## @end group
+## @end example
+##
+## @noindent
+## will directly draw a random isosurface geometry in a graphics window.
+## Another example for an isosurface geometry with different additional
+## coloring
+## @c Set example in small font to prevent overfull line
+##
+## @smallexample
+## N = 15; # Increase number of vertices in each direction
+## iso = .4; # Change isovalue to .1 to display a sphere
+## lin = linspace (0, 2, N);
+## [x, y, z] = meshgrid (lin, lin, lin);
+## c = abs ((x-.5).^2 + (y-.5).^2 + (z-.5).^2);
+## figure (); # Open another figure window
+##
+## subplot (2,2,1); view (-38, 20);
+## [f, v] = isosurface (x, y, z, c, iso);
+## p = patch ("Faces", f, "Vertices", v, "EdgeColor", "none");
+## set (gca, "PlotBoxAspectRatioMode", "manual", ...
+## "PlotBoxAspectRatio", [1 1 1]);
+## # set (p, "FaceColor", "green", "FaceLighting", "phong");
+## # light ("Position", [1 1 5]); # Available with the JHandles package
+##
+## subplot (2,2,2); view (-38, 20);
+## p = patch ("Faces", f, "Vertices", v, "EdgeColor", "blue");
+## set (gca, "PlotBoxAspectRatioMode", "manual", ...
+## "PlotBoxAspectRatio", [1 1 1]);
+## # set (p, "FaceColor", "none", "FaceLighting", "phong");
+## # light ("Position", [1 1 5]);
+##
+## subplot (2,2,3); view (-38, 20);
+## [f, v, c] = isosurface (x, y, z, c, iso, y);
+## p = patch ("Faces", f, "Vertices", v, "FaceVertexCData", c, ...
+## "FaceColor", "interp", "EdgeColor", "none");
+## set (gca, "PlotBoxAspectRatioMode", "manual", ...
+## "PlotBoxAspectRatio", [1 1 1]);
+## # set (p, "FaceLighting", "phong");
+## # light ("Position", [1 1 5]);
+##
+## subplot (2,2,4); view (-38, 20);
+## p = patch ("Faces", f, "Vertices", v, "FaceVertexCData", c, ...
+## "FaceColor", "interp", "EdgeColor", "blue");
+## set (gca, "PlotBoxAspectRatioMode", "manual", ...
+## "PlotBoxAspectRatio", [1 1 1]);
+## # set (p, "FaceLighting", "phong");
+## # light ("Position", [1 1 5]);
+## @end smallexample
+##
+## @seealso{isonormals, isocolors}
+## @end deftypefn
+
+## Author: Martin Helm <martin@mhelm.de>
+
+function varargout = isosurface(varargin)
+
+ if (nargin < 2 || nargin > 8 || nargout > 3)
+ print_usage ();
+ endif
+
+ calc_colors = false;
+ f = v = c = [];
+ verbose = false;
+ noshare = false;
+ if (nargin >= 5)
+ x = varargin{1};
+ y = varargin{2};
+ z = varargin{3};
+ val = varargin{4};
+ iso = varargin{5};
+ if (nargin >= 6 && ismatrix (varargin{6}))
+ colors = varargin{6};
+ calc_colors = true;
+ endif
+ else
+ val = varargin{1};
+ [n2, n1, n3] = size (val);
+ [x, y, z] = meshgrid (1:n1, 1:n2, 1:n3);
+ iso = varargin{2};
+ if (nargin >= 3 && ismatrix (varargin{3}))
+ colors = varargin{3};
+ calc_colors = true;
+ endif
+ endif
+ if (calc_colors)
+ if (nargout == 2)
+ warning ( "Colors will be calculated, but you did not specify an output argument for it!" );
+ endif
+ [fvc.faces, fvc.vertices, fvc.facevertexcdata] = __marching_cube__ (x, y, z, val, iso, colors);
+ else
+ [fvc.faces, fvc.vertices] = __marching_cube__ (x, y, z, val, iso);
+ endif
+
+ if (isempty (fvc.vertices) || isempty (fvc.faces))
+ warning ( "The resulting triangulation is empty" );
+ endif
+
+ switch (nargout)
+ case 0
+ ## plot the calculated surface
+ newplot ();
+ if (calc_colors)
+ pa = patch ("Faces", fvc.faces, "Vertices", fvc.vertices,
+ "FaceVertexCData", fvc.facevertexcdata,
+ "FaceColor", "flat", "EdgeColor", "none");
+ else
+ pa = patch ("Faces", fvc.faces, "Vertices", fvc.vertices,
+ "FaceColor", "g", "EdgeColor", "k");
+ endif
+ if (! ishold ())
+ set (gca(), "view", [-37.5, 30],
+ "xgrid", "on", "ygrid", "on", "zgrid", "on");
+ endif
+ case 1
+ varargout = {fvc};
+ case 2
+ varargout = {fvc.faces, fvc.vertices};
+ case 3
+ varargout = {fvc.faces, fvc.vertices, fvc.facevertexcdata};
+ otherwise
+ print_usage ();
+ endswitch
+
+endfunction
+
+
+%!shared x, y, z, val
+%! [x, y, z] = meshgrid (0:1, 0:1, 0:1); ## Points for single
+%! val = [0, 0; 0, 0]; ## cube and a 3--dim
+%! val(:,:,2) = [0, 0; 1, 0]; ## array of values
+%!test
+%! fv = isosurface (x, y, z, val, 0.3);
+%! assert (isfield (fv, "vertices"), true);
+%! assert (isfield (fv, "faces"), true);
+%! assert (size (fv.vertices), [3 3]);
+%! assert (size (fv.faces), [1 3]);
+%!test
+%! fvc = isosurface (x, y, z, val, .3, y);
+%! assert (isfield (fvc, "vertices"), true);
+%! assert (isfield (fvc, "faces"), true);
+%! assert (isfield (fvc, "facevertexcdata"), true);
+%! assert (size (fvc.vertices), [3 3]);
+%! assert (size (fvc.faces), [1 3]);
+%! assert (size (fvc.facevertexcdata), [3 1]);
+%!test
+%! [f, v] = isosurface (x, y, z, val, .3);
+%! assert (size (f), [1 3]);
+%! assert (size (v), [3 3]);
+%!test
+%! [f, v, c] = isosurface (x, y, z, val, .3, y);
+%! assert (size (f), [1 3]);
+%! assert (size (v), [3 3]);
+%! assert (size (c), [3 1]);
+
+%!demo
+%! clf
+%! [x,y,z] = meshgrid(-2:0.5:2, -2:0.5:2, -2:0.5:2);
+%! v = x.^2 + y.^2 + z.^2;
+%! isosurface (x, y, z, v, 1)
git://git.creatis.insa-lyon.fr / CreaPhase.git / blobdiff