Boundary-based generative design with 2.5-axis subtractive manufacturing constraint for computer aided design and manufacturing

Methods, systems, and apparatus, including medium-encoded computer program products, for computer aided design of physical structures using generative design processes, where the three dimensional (3D) models of the physical structures are produced so as to facilitate manufacturing of the physical structures using 2.5-axis subtractive manufacturing systems and techniques, include: obtaining a design space for an object to be manufactured and one or more design criteria including at least one manufacturability constraint for the object; performing a boundary-based generative design process to produce a generative model for the object using the one or more design criteria that includes at least one manufacturability constraint corresponding to a 2.5-axis subtractive manufacturing process; and providing a three dimensional model in accordance with the generative model, for use in manufacturing a physical structure using one or more computer-controlled manufacturing systems that employ the 2.5-axis subtractive ma