In this paper, we describe a system of composite images to design virtual three-dimensional structures in an outdoor environment. The system, called AmbiViewer, consists of a modeler for three-dimensional on-site sketching, and overlapping locative technologies to orient virtual objects in a real-space, real-time setting. The system employs both GPS orientation and a visual marker system to provide a realistic and interactive augmented reality interface. While it is still under development, the authors believe it can bridge the gap between sketching on site, and creating virtual models in the office.