This paper presents a virtual prototyping (VP) approach for geometric mouldability analysis of near-net-shape manufactured parts. The geometric mouldability of a part depends on the geometry of the part and is affected by the number and types of undercut features. A virtual prototype (VP) of a mold, which is a realistic digital product model, is generated by combining automated and interactive approaches to evaluate the mouldability of a part in the early stages of the product development cycle. The automated approaches for generating a VP are proposed to construct the parting surface, cores and cavity of the mold based on the recognized undercut features. Interaction with the VP in the virtual reality environment allows the designers to evaluate the mouldability of a part in an intuitive way. A new volume-based feature recognition method and data structure using non-directional blocking graph (NDBG) have been developed to recognize both isolated and interacting undercut features in a uniform way. Firstly, a set of potential undercuts are generated by performing the regularized difference between the part and its convex hull. The optimal parting direction is then determined by minimizing the number of undercuts. Finally, undercut features are identi