Method and apparatus for making a three-dimensional object by stereolithography

A method for automatically inserting a drain or vent in a vertical or a sloped surface of a three-dimensional object representation, comprising:

• taking as input the three-dimensional object representation, which representation comprises a plurality of boundaries of cross-sections of the object;
• taking as input data descriptive of the drain or vent;
• and
• modifying at least one of said cross-sectional boundaries by performing a Boolean operation between data descriptive of said cross-sectional boundary and said data descriptive of said drain or vent.

A method for automatically inserting a drain or vent in a sloped surface of a first three-dimensional object representation, comprising:

• supplying the first object representation, the first object representation having at least one sloped surface;
• selecting a second object representation having at least one of a vertical surface or a flat surface;
• relatively orienting the first and second object representations such that the flat surface and/or the vertical surface of the second object representation is situated near the at least one sloped surface of the first object representation;
• performing a Boolean operation between the first and second object representations to form a modified first object representation, including a flat surface or vertical surface formed at the at least one sloped surface;
• and
• inserting the drain or vent in the flat or vertical surface of the modified first object representation.

A method of constructing a three-dimensional object from a solidifiable medium, comprising:

• supplying data descriptive of the object;
• forming layers of unsolidified medium adjacent to previously formed cross-sections of the object in preparation for forming subsequent cross-sections of the object;
• selectively exposing the layers of unsolidified medium to prescribed stimulation to selectively solidify portions of the layers to form successive cross-sections of the object;
• automatically adhering the cross-sections together upon formation to construct the three-dimensional object cross-section by cross-section, the object comprising object regions and non-object regions separated bv surfaces of the object;
• and
• leaving at least a portion of the surface of the object unsolidified to form a passage from the object region to the non-object region so as to allow at least a portion of any unsolidified medium within the object region to be at least partially removed through the passage,
• wherein the surface region remaining unsolidified results from the removal of surface data descriptive of the surface, and
• wherein the medium is a liquid photopolymer, and
• wherein the passage is specified on the surface by specifying a location and a passage size.