Interactive design of 3D models with geometric constraints

In this paper, an interactive graphical approach for the design of parameterized part-hierarchies is presented. Primitive solids can be grouped into compound objects, and multiple instances of a compound object can be used in further designs. Geometric relations between primitives and instances are specified by geometric constraints between their local coordinate systems. The user can specify and edit a model by direct manipulation on a perspective or parallel projection with a mouse, whereas a procedural model representations is automatically generated via visual programming. The obtained twoview approach offers two concurrent interface styles to the end-user and enables the combination of an intuitive direct manipulation interface with the expressiveness of a procedural modeling language.