A method of designing an electric circuit includes generating a part of the design, determining a virtual shape based on the part, and using the virtual shape to generate a design for an additional part. Design elements of the additional part, such as its size, location, or orientation for example, may be determined with the virtual shape. The method may also generate multiple virtual shapes based on the part, and may use one or more of the multiple virtual shapes to generate the next part. The method may be repeated to generate additional parts of the design using virtual shapes.