AbstractProcedural modeling technology may be applied for constructing a large‐scale urban scene. Most of the previous studies have exploited a grammar‐based modeling method to generate models. Nevertheless, we formulate the urban planning as a constrained layout optimization problem, propose an algorithm to solve the problem, and procedurally generate models of the urban zone. It produces an extensive urban virtual environment for computer games and simulations at low cost. We optimize a cost function to distribute buildings and roads subject to some urban planning constraints. We employ particle swarm optimization and two‐step path planning to find the optimal solution, which is further interpreted as the 2D blueprint of the urban zone. During the optimization, we adopt the spatial pattern tree structure to reduce the combinational search space greatly. 3D city models in large scale are then assembled according to the 2D blueprints. Experimental results prove that our method can efficiently produce the virtual urban scene similar to that designed by urban planners. Copyright © 2008 John Wiley & Sons, Ltd.