Xcmodel 3.0 — an Academic Modeling/rendering System

Non-Uniform Rational B-Splines (NURBS) is a well-established tool for geometric design having become the de facto industry standards for the representation, design, and data exchange of geometric information. The introduction of a trimmed surface data type in the description of free form objects or parts of solids has provided greater power and flexibility to the standard NURBS representational schemes, overcoming the limit of tensor product surfaces defined over rectangular regions, and allowing for arbitrary domains. xcmodel is a modeling/rendering system realized and usable in an academic environment which summarises our knowledge and experience in geometric modeling and NURBS curves and surfaces acquired over ten years of research. xcmodel and its subsystems were designed to represent a research and teaching laboratory to experiment and learn, so it is an ideal environment to develop, perfect and compare methods and algorithms in geometric modeling and graphics visualization, assuming trimmed NURBS as the only shape primitive for its purposes. In this paper we present the third version of the system, describing its functionalities, enhancements and add-ons with respect to the previous versions.