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diff --git a/samples/s005_3d_geometry.m b/samples/s005_3d_geometry.m
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+%------------------------------------------------------------------------
+% This file is part of the
+% All Scale Tomographic Reconstruction Antwerp Toolbox ("ASTRA-Toolbox")
+%
+% Copyright: iMinds-Vision Lab, University of Antwerp
+% License: Open Source under GPLv3
+% Contact: mailto:astra@ua.ac.be
+% Website: http://astra.ua.ac.be
+%------------------------------------------------------------------------
+
+vol_geom = astra_create_vol_geom(64, 64, 64);
+
+
+% There are two main 3d projection geometry types: cone beam and parallel beam.
+% Each has a regular variant, and a 'vec' variant.
+% The 'vec' variants are completely free in the placement of source/detector,
+% while the regular variants assume circular trajectories around the z-axis.
+
+
+% -------------
+% Parallel beam
+% -------------
+
+
+% Circular
+
+% Parameters: width of detector column, height of detector row, #rows, #columns
+angles = linspace2(0, 2*pi, 48);
+proj_geom = astra_create_proj_geom('parallel3d', 1.0, 1.0, 32, 64, angles);
+
+
+% Free
+
+% We generate the same geometry as the circular one above. 
+vectors = zeros(numel(angles), 12);
+for i = 1:numel(angles)
+  % ray direction
+  vectors(i,1) = sin(angles(i));
+  vectors(i,2) = -cos(angles(i));
+  vectors(i,3) = 0;	
+
+  % center of detector
+  vectors(i,4:6) = 0;
+
+  % vector from detector pixel (0,0) to (0,1)
+  vectors(i,7) = cos(angles(i));
+  vectors(i,8) = sin(angles(i));
+  vectors(i,9) = 0;
+
+  % vector from detector pixel (0,0) to (1,0)
+  vectors(i,10) = 0;
+  vectors(i,11) = 0;
+  vectors(i,12) = 1;
+end
+
+% Parameters: #rows, #columns, vectors
+proj_geom = astra_create_proj_geom('parallel3d_vec', 32, 64, vectors);
+
+% ----------
+% Cone beam
+% ----------
+
+
+% Circular
+
+% Parameters: width of detector column, height of detector row, #rows, #columns,
+%             angles, distance source-origin, distance origin-detector
+angles = linspace2(0, 2*pi, 48);
+proj_geom = astra_create_proj_geom('cone', 1.0, 1.0, 32, 64, ...
+                                   angles, 1000, 0);
+
+% Free
+
+vectors = zeros(numel(angles), 12);
+for i = 1:numel(angles)
+
+	% source
+	vectors(i,1) = sin(angles(i)) * 1000;
+	vectors(i,2) = -cos(angles(i)) * 1000;
+	vectors(i,3) = 0;	
+
+	% center of detector
+	vectors(i,4:6) = 0;
+
+	% vector from detector pixel (0,0) to (0,1)
+	vectors(i,7) = cos(angles(i));
+	vectors(i,8) = sin(angles(i));
+	vectors(i,9) = 0;
+
+	% vector from detector pixel (0,0) to (1,0)
+	vectors(i,10) = 0;
+	vectors(i,11) = 0;
+	vectors(i,12) = 1;		
+end
+
+% Parameters: #rows, #columns, vectors
+proj_geom = astra_create_proj_geom('cone_vec', 32, 64, vectors);
+