1. A method of creating a design of a sketch-based eggcrate substructure for manufacturing composite parts, comprising: providing an input model from a plurality of inputs, including: providing a layout geometry; and providing a specification data structure; creating a resolution model of the input model, including: interpolating the layout geometry; and interpolating the specification data structure; finalizing a layout using the resolution model; and providing one or more solid components into the finalized resolution model to create the design.