# HG changeset patch # User Thomas Treichl # Date 1239739325 -7200 # Node ID 3b810beddfa64d947c1fe399b17f325d70e0eac1 # Parent 308311b642b2be2c4e171e15b9e8f35ea4615975 Added help texts and tests. diff -r 308311b642b2 -r 3b810beddfa6 scripts/ChangeLog --- a/scripts/ChangeLog Tue Apr 14 21:22:24 2009 +0200 +++ b/scripts/ChangeLog Tue Apr 14 22:02:05 2009 +0200 @@ -1,4 +1,9 @@ -2009-04-11 David Bateman +2009-04-14 Thomas Treichl + + * plot/__marching_cube__.m: Add help text. + * plot/isonormals.m: Add help text and tests. + +2009-04-14 David Bateman * plot/__patch__.m: Set default facecolor to [0,1,0]. diff -r 308311b642b2 -r 3b810beddfa6 scripts/plot/__marching_cube__.m --- a/scripts/plot/__marching_cube__.m Tue Apr 14 21:22:24 2009 +0200 +++ b/scripts/plot/__marching_cube__.m Tue Apr 14 22:02:05 2009 +0200 @@ -12,52 +12,63 @@ ## ## You should have received a copy of the GNU General Public License ## along with this program; if not, see http://www.gnu.org/licenses/gpl.html. -## -## Author: Martin Helm ## -*- texinfo -*- -## @deftypefn {Function File} {[@var{t}, @var{p}, @var{col}] =} __marching_cube__ (@var{x}, @var{y}, @var{z}, @var{c}, @var{iso}, @var{color}) -## Undocumented internal function. +## @deftypefn {Function File} {[@var{t}, @var{p}] =} __marching_cube__ (@var{x}, @var{y}, @var{z}, @var{val}, @var{iso}) +## @deftypefn {Function File} {[@var{t}, @var{p}, @var{c}] =} __marching_cube__ (@var{x}, @var{y}, @var{z}, @var{val}, @var{iso}, @var{col}) +## +## Return the triangulation information @var{t} at points @var{p} for +## the isosurface values resp. the volume data @var{val} and the iso +## level @var{iso}. It is considered that the volume data @var{val} is +## given at the points @var{x}, @var{y} and @var{z} which are of type +## three--dimensional numeric arrays. The orientation of the triangles +## is choosen such that the normals point from the higher values to the +## lower values. +## +## Optionally the color data @var{col} can be passed to this function +## whereas computed vertices color data @var{c} is returned as third +## argument. +## +## The marching cube algorithm is well known and described eg. at +## Wikipedia. The triangulation lookup table and the edge table used +## here are based on Cory Gene Bloyd's implementation and can be found +## beyond other surface and geometry stuff at Paul Bourke's website +## @uref{http://local.wasp.uwa.edu.au/~pbourke/geometry/polygonise}. +## +## For example, +## @example +## N = 20; +## lin = linspace(0, 2, N); +## [x, y, z] = meshgrid (lin, lin, lin); +## +## c = (x-.5).^2 + (y-.5).^2 + (z-.5).^2; +## [t, p] = __marching_cube__ (x, y, z, c, .5); +## +## figure (); +## trimesh (t, p(:,1), p(:,2), p(:,3)); +## @end example +## +## Instead of the @command{trimesh} function the @command{patch} +## function can be used to visualize the geometry. For example, +## +## @example +## figure (); view (-38, 20); +## pa = patch ("Faces", t, "Vertices", p, "FaceVertexCData", p, \ +## "FaceColor", "interp", "EdgeColor", "none"); +## +## ## Revert normals +## set (pa, "VertexNormals", -get(pa, "VertexNormals")); +## +## ## Set lightning (available with the JHandles package) +## # set (pa, "FaceLighting", "gouraud"); +## # light( "Position", [1 1 5]); +## @end example +## ## @end deftypefn -## usage: [T, P] = marching_cube( XX, YY, ZZ, C, ISO) -## usage: [T, P, COL] = marching_cube( XX, YY, ZZ, C, ISO, COLOR) -## -## Calculates the triangulation T with points P for the isosurface -## with level ISO. XX, YY, ZZ are meshgrid like values for the -## cube and C holds the scalar values of the field, -## COLOR holds additinal scalar values for coloring the surface. -## The orientation of the triangles is choosen such that the -## normals point from the lower values to the higher values. -## -## edgeTable and triTable are taken from Paul Bourke -## (http://local.wasp.uwa.edu.au/~pbourke/geometry/polygonise/) -## Based on tables by Cory Gene Bloyd -## -## Example: -## -## x = linspace(0, 2, 20); -## y = linspace(0, 2, 20); -## z = linspace(0, 2, 20); -## -## [ xx, yy, zz ] = meshgrid(x, y, z); -## -## c = (xx-.5).^2 + (yy-.5).^2 + (zz-.5).^2; -## [T, p] = marching_cube(xx, yy, zz, c, 0.5); -## trimesh(T, p(:, 1), p(:, 2), p(:, 3)); -## -## with jhandles you can also use the patch function to visualize -## -## clf -## pa = patch('Faces',T,'Vertices',p,'FaceVertexCData',p, ... -## 'FaceColor','interp', 'EdgeColor', 'none'); -## set(pa, "VertexNormals", -get(pa, "VertexNormals")) # revert normals -## view(-30, 30) -## set(pa, "FaceLighting", "gouraud") -## light( "Position", [1 1 5]) -## +## Author: Martin Helm -function [T, p, col] = __marching_cube__( xx, yy, zz, c, iso, colors) +function [T, p, col] = __marching_cube__ (xx, yy, zz, c, iso, colors) persistent edge_table=[]; persistent tri_table=[]; @@ -502,4 +513,4 @@ 0, 9, 1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1; 0, 3, 8, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1; -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 ] + 1; -endfunction \ No newline at end of file +endfunction diff -r 308311b642b2 -r 3b810beddfa6 scripts/plot/isonormals.m --- a/scripts/plot/isonormals.m Tue Apr 14 21:22:24 2009 +0200 +++ b/scripts/plot/isonormals.m Tue Apr 14 22:02:05 2009 +0200 @@ -12,17 +12,83 @@ ## ## You should have received a copy of the GNU General Public License ## along with this program; if not, see http://www.gnu.org/licenses/gpl.html. -## -## Author: Martin Helm -## usage: NORMALS = isonormals(X,Y,Z,V,VERT) -## usage: NORMALS = isonormals(V,VERT) -## usage: NORMALS = isonormals(V,P) -## usage: NORMALS = isonormals(X,Y,Z,V,P) -## usage: NORMALS = isonormals(...,'negate') -## usage: isonormals(V,P) -## usage: isonormals(X,Y,Z,V,P) +## -*- texinfo -*- +## @deftypefn {Function File} {[@var{n}] =} isonormals (@var{val}, @var{v}) +## @deftypefnx {Function File} {[@var{n}] =} isonormals (@var{val}, @var{p}) +## @deftypefnx {Function File} {[@var{n}] =} isonormals (@var{x}, @var{y}, @var{z}, @var{val}, @var{v}) +## @deftypefnx {Function File} {[@var{n}] =} isonormals (@var{x}, @var{y}, @var{z}, @var{val}, @var{p}) +## @deftypefnx {Function File} {[@var{n}] =} isonormals (@dots{}, "negate") +## @deftypefnx {Function File} isonormals (@dots{}, @var{p}) +## +## If called with one output argument and the first input argument +## @var{val} is a three--dimensional array that contains the data for an +## isosurface geometry and the second input argument @var{v} keeps the +## vertices of an isosurface then return the normals @var{n} in form of +## a matrix with the same size than @var{v} at computed points +## @command{[x, y, z] = meshgrid (1:l, 1:m, 1:n)}. The output argument +## @var{n} can be taken to manually set @var{VertexNormals} of a patch. +## +## 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. Instead of the +## vertices data @var{v} a patch handle @var{p} can be passed to this +## function. +## +## If given the string input argument "negate" as last input argument +## then compute the reverse vector normals of an isosurface geometry. +## +## If no output argument is given then directly redraw the patch that is +## given by the patch handle @var{p}. +## +## For example, +## @example +## function [] = isofinish (p) +## set (gca, "DataAspectRatioMode","manual","DataAspectRatio",[1 1 1]); +## set (p, "VertexNormals", -get(p,"VertexNormals")); ## Revert normals +## set (p, "FaceColor", "interp"); +## ## set (p, "FaceLighting", "phong"); +## ## light ("Position", [1 1 5]); ## Available with JHandles +## endfunction ## +## 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, cdat] = isosurface (x, y, z, c, iso, y); +## p = patch ("Faces", f, "Vertices", v, "FaceVertexCData", cdat, \ +## "FaceColor", "interp", "EdgeColor", "none"); +## isofinish (p); ## Call user function isofinish +## +## subplot (2, 2, 2); view (-38, 20); +## p = patch ("Faces", f, "Vertices", v, "FaceVertexCData", cdat, \ +## "FaceColor", "interp", "EdgeColor", "none"); +## isonormals (x, y, z, c, p); ## Directly modify patch +## isofinish (p); +## +## subplot (2, 2, 3); view (-38, 20); +## p = patch ("Faces", f, "Vertices", v, "FaceVertexCData", cdat, \ +## "FaceColor", "interp", "EdgeColor", "none"); +## n = isonormals (x, y, z, c, v); ## Compute normals of isosurface +## set (p, "VertexNormals", n); ## Manually set vertex normals +## isofinish (p); +## +## subplot (2, 2, 4); view (-38, 20); +## p = patch ("Faces", f, "Vertices", v, "FaceVertexCData", cdat, \ +## "FaceColor", "interp", "EdgeColor", "none"); +## isonormals (x, y, z, c, v, "negate"); ## Use reverse directly +## isofinish (p); +## @end example +## +## @seealso {isosurface, isocolors, isocaps, marching_cube} +## +## @end deftypefn + +## Author: Martin Helm function varargout = isonormals(varargin) na = nargin; @@ -75,4 +141,18 @@ otherwise print_usage (); endswitch -endfunction \ No newline at end of file +endfunction + +%!test +%! [x, y, z] = meshgrid (0:.5:2, 0:.5:2, 0:.5:2); +%! c = abs ((x-.5).^2 + (y-.5).^2 + (z-.5).^2); +%! [f, v, cdat] = isosurface (x, y, z, c, .4, y); +%! n = isonormals (x, y, z, c, v); +%! assert (size (v), size (n)); +%!test +%! [x, y, z] = meshgrid (0:.5:2, 0:.5:2, 0:.5:2); +%! c = abs ((x-.5).^2 + (y-.5).^2 + (z-.5).^2); +%! [f, v, cdat] = isosurface (x, y, z, c, .4, y); +%! np = isonormals (x, y, z, c, v); +%! nn = isonormals (x, y, z, c, v, "negate"); +%! assert (all (np == -nn));