Abstract: An improved advancing front method is proposed for the automatic generation of quadrilateral grid. Background grid does not need to be configured first, and the multimedia complex domain is divided into several closed sub-domains. Information of points and lines from these closed sub-domain boundaries are automatically extracted from the AutoCAD model. The generation of internal nodes is controlled with grid density parameters and topology of points and lines from the closed domain. Grid density is controlled by the global density parameter and the relative size of adjacent sub-domains. Grid quality evaluation system and multiple refinement measures are used to improve the grid quality. The whole domain is divided into triangle grids, which are optimized and subsequently combined or divided to generate quadrilateral elements. Good quadrilateral grids are obtained by optimization measures once again. Examples of the grid generation for computational domain of a railway embankment section and the No.2 unit section of Pubugou power station underground plant demonstrate  the feasibility and reliability of this method.

Key words:  improved advancing front method, multimedia and complex domain, quadrilateral grid, automatic generation