Procedural modeling of three-dimensional geometry

Modelling three-dimensional shapes plays an increasingly significant role in modern computer graphics. Geometry synthesis is used in many fields, including digital cinema, electronic entertainment and computer simulations. Unfortunately, the modelling process is still done manually, offering a unique output at the cost of tedious work. There is a constant need to replace designers' work with intelligent automated algorithms. The methods based on the automation of modelling processes offer a variety of three-dimensional structures within limited time and restricted money budget. This paper addresses the problem of automated modelling of virtual structures such as caves, buildings and clouds, and presents an alternative solution in the form of a hybrid system. The innovative approach combines two independent methods well known in three-dimensional computer graphics: shape grammar and shape morphing. In the modelling process, it is possible to obtain the characteristics of 3D structures with non-spherical mesh topology. The objects and their transformations are described by functions, while rule grammars define the geometry modelling process. The shapes thus obtained can be freely deformed in the subsequent rules. The resulting structure can be rendered up to very high levels of visual realism. However, in the paper we present the description of the algorithm illustrated by results on a 3D mesh without focusing on photorealistic rendering aspects. We also propose some measures that can be used to verify the model geometry.