Wireframe modelling has been discredited as a primary shape representation technique, but is still useful as a fast way to display simple objects, in particular when selecting projections. Computing wireframes from set-theoretic solid models is potentially very time-consuming. Recursive division of the object space may easily be used to accelerate this process, but the resulting wireframes are unnecessarily segmented. By searching for the vertices of a model and deriving submodels, which are then used to find edges between vertices, a program has been written that both exhibits the good complexity performance of recursive division and produces wireframes containing maximal length wires. © 1986.