Application of a Formal Grammar to Facade Reconstruction in Semiautomatic and Automatic Environments

3d city models are used in a huge number of applications today. They are applicable in the area of urban planning and city development, tourism and marketing and as well for navigation. All these applications need a 3d city model of a large area. And in these days the desire for actuality and a high degree of details is rising. Due to this the modelling of buildings as block models as before is not sufficient any more. There is a need for facade reconstruction methods that model windows and other facade elements in more detail. To acquire the huge demand of models, automatic methods are needed. In this paper we show the importance of the use of structure information for the reconstruction process. With an example we demonstrate the problems of reconstructions methods which work without structure information. Then we present how to use a grammar to integrate structure in the process. Thereafter we present a manual modelling tool which is based on our facade grammar. And finally an automatic facade reconstruction method based on reversible jump Markov Chain Monte Carlo (rjMCMC) is shown.