Converting a 3D logical array into an STL surface mesh

Converting a 3D logical array into an STL surface mesh
======================================================

Adam H. Aitkenhead
adam.aitkenhead@christie.nhs.uk
The Christie NHS Foundation Trust
24th May 2010


USAGE
=====

>> CONVERT_voxels_to_stl(STLname,gridDATA,gridX,gridY,gridZ,'ascii')
..or..
>> [faces,vertices] = CONVERT_voxels_to_stl(STLname,gridDATA,gridX,gridY,gridZ,STLformat)

converts the voxelised object contained within the 3D logical array <gridINPUT> into an STL surface mesh, which is saved to the ascii file <STLin>. The x,y,z axes for <gridINPUT> are defined by <gridX>, <gridY> and <gridZ>. The (faces,vertices) data are optional outputs.


INPUTS
======

STLname - string - Filename of the STL file.
gridINPUT - 3D logical array of size (P,Q,R) - The voxelised object (1 => Inside the object, 0 => Outside the object)
gridX - A 1xP array - List of the X axis coordinates.
gridY - A 1xQ array - List of the Y axis coordinates.
gridZ - A 1xR array - List of the Z axis coordinates.
STLformat - string (optional) - STL file format: 'binary' or 'ascii'.


OUTPUTS
=======

faces - Nx3 array - A list of the vertices used in each facet of the mesh, identified using the row number in the array vertices.
vertices - Nx3 array - A list of the x,y,z coordinates of each vertex in the mesh.


EXAMPLE
=======

For an example, run the following script:
>> CONVERT_voxels_to_stl_example


NOTES
=====

- This code does not apply any smoothing. The stl mesh will be exactly the same geometry as the original voxelised object.