Procedural modeling and layout method for a generic ancient Chinese city

This paper mainly proposes a city layout method based on the L-System method generated for an ancient Chinese cities. This method is improved by adding local constraints improvements, adding a symmetric factor, and introducing a distance constraint to guide the layout generation, so that the improved SE L-System can generate a symmetric urban layout and the degree of symmetry of the city can be globally controlled by the user. A building level control function is proposed to realize the mapping from building location to building level and then to specific building parameters. Based on the parameters, ancient building complexes with different appearances and layouts that conform to the layout rules of ancient Chinese cities can be generated. Buildings are generated based on the L-System, and trees are generated at arbitrary positions according to the probability density of generated trees determined by the building density. Based on the convex hull and intersection of rays, the city walls and watch tower of the ancient city are generated, and the procedural modeling generation of a complete ancient Chinese city is realized. The experimental results show that the square and symmetrical structure of the ancient city layout generated by SE L-System is closer to a real ancient Chinese city layout.