Converting at least a portion of a 3-d object into a format suitable for printing

Apparatus for converting at least a portion of a 3-D object into a format suitable for printing, the apparatus comprising:

• a processor to determine a material volume area coverage vector for each voxel of a 3-D bit map of a 3-D object, the 3-D bit map comprising a plurality of voxels, each voxel located at a unique 3-D location;
• and to determine a rectangular cuboid comprising an M×N×L array of voxel locations enclosing at least a portion of the 3-D object;
• a replicator to replicate a provided halftone threshold matrix to an M×N×L 3-D array of threshold values;
• and
• a comparator to compare each material volume coverage vector with each threshold value of the replicated 3-D halftone threshold matrix at corresponding 3-D locations to select a printable voxel at each 3-D location to convert the at least a portion of the 3-D object into a format suitable for printing.

One or more computer-readable storage media comprising instructions stored thereon, that when executed;

• direct a processor to perform a method comprising:
• determining a material volume coverage vector for each voxel of a 3-D bit map of a 3-D object, the 3-D bit map comprising a plurality of voxels, each voxel located at a unique 3-D location;
• determining a rectangular cuboid comprising an M×N×L array of voxel locations enclosing at least a portion of the 3-D object;
• and
• replicating a provided halftone threshold matrix to an M×N×L 3-D array of threshold values.