Dimensional compensations for additive manufacturing

A method of dimensional compensation in additive manufacturing comprising:

• receiving object model data representing an object with intended dimensions to be generated in a fabrication chamber by a thermal fusing process in which heat is applied to layers of build material to selectively solidify portions of the layers of build material;
• determining an object location within the chamber where the object is to be generated;
• applying a dimensional compensation to the object model data that is determined based on thermal conditions within the chamber at the object location, the dimensional compensation to compensate for anticipated departures from the intended dimensions induced by applying the heat during the thermal fusing process;
• determining object generation instructions for generating the object according to the dimensionally compensated object model data;
• and,
• generating the object based on the object generation instructions.