This paper, delivered at the recent Huddersfield University World Textile Congress, describes how multi-layer and orthogonal 3D woven structures can be parameterised, and solid models developed in order to assist the design and manufacture of these structures and to provide models for geometric and mechanical analysis. Two major types of three dimensional woven structures are studied, and mathematical models for these are described. These models have been used in the development of CAD/CAM software packages for the design and manufacture of complicated woven structures for industrial end uses. The 3D weave generation techniques described in this paper can also be implemented in even more complex woven structures which use these structures as component weaves. The solid models generated, when incorporated with fibre, yarn, and fabric information, can then be used for evaluations of geometric, physical and mechanical properties of the 3D structures.