Code covered by the BSD License

# geom3d

### David Legland (view profile)

19 Jun 2009 (Updated )

Library to handle 3D geometric primitives: create, intersect, display, and make basic computations

### Editor's Notes:

This file was selected as MATLAB Central Pick of the Week

drawCuboid(cuboid, varargin)
```function varargout = drawCuboid(cuboid, varargin)
%DRAWCUBOID Draw a 3D cuboid, eventually rotated
%
%   drawCuboid(CUBOID)
%   Displays a 3D cuboid on current axis. CUBOID is given by:
%   [XC YC ZC L W D YAW PITCH ROLL],
%   where (XC, YC, ZC) is the cuboid center, L, W and H are the lengths of
%   the cuboid main axes, and YAW PITCH ROLL are Euler angles representing
%   the cuboid orientation, in degrees.
%
%   If cuboid is axis-aligned, it can be specified using only center and
%   side lengths:
%   CUBOID = [XC YC ZC L W H]
%
%   Example
%   % Draw a basic rotated cuboid
%     figure; hold on;
%     drawCuboid([10 20 30   90 40 10   10 20 30], 'FaceColor', 'g');
%     axis equal;
%     view(3);
%
%     % Draw three "borromean" cuboids
%     figure; hold on;
%     drawCuboid([10 20 30 90 50 10], 'FaceColor', 'r');
%     drawCuboid([10 20 30 50 10 90], 'FaceColor', 'g');
%     drawCuboid([10 20 30 10 90 50], 'FaceColor', 'b');
%     view(3); axis equal;
%     set(gcf, 'renderer', 'opengl')
%
%   meshes3d, polyhedra, createCube, drawEllipsoid, drawCube
%

% ------
% Author: David Legland
% e-mail: david.legland@grignon.inra.fr
% Created: 2011-06-29,    using Matlab 7.9.0.529 (R2009b)
% Copyright 2011 INRA - Cepia Software Platform.

phi   = 0;
theta = 0;
psi   = 0;

%% Parses the input
if nargin == 0
% no input: assumes cuboid with default shape
xc = 0;	yc = 0; zc = 0;
a = 5; b = 4; c = 3;

else
% one argument: parses elements
xc  = cuboid(:,1);
yc  = cuboid(:,2);
zc  = cuboid(:,3);
a   = cuboid(:,4);
b   = cuboid(:,5);
c   = cuboid(:,6);
if size(cuboid, 2) >= 9
k   = pi / 180;
phi   = cuboid(:,7) * k;
theta = cuboid(:,8) * k;
psi   = cuboid(:,9) * k;
end
end

%% Compute cuboid coordinates

% create unit centered cube
[v, f] = createCube;
v = bsxfun(@minus, v, mean(v, 1));

% convert unit basis to ellipsoid basis
sca     = createScaling3d(a, b, c);
rotZ    = createRotationOz(phi);
rotY    = createRotationOy(theta);
rotX    = createRotationOx(psi);
tra     = createTranslation3d([xc yc zc]);

% concatenate transforms
trans   = tra * rotZ * rotY * rotX * sca;

% transform mesh vertices
[x, y, z] = transformPoint3d(v, trans);

%% Process output
if nargout == 0
% no output: draw the cuboid
drawMesh([x y z], f, varargin{:});

elseif nargout == 1
% one output: draw the cuboid and return handle
varargout{1} = drawMesh([x y z], f, varargin{:});

elseif nargout == 3
% 3 outputs: return computed coordinates
varargout{1} = x;
varargout{2} = y;
varargout{3} = z;
end

```