In this study, we introduce the history of adapting real-time simulation to Environmental Design, and develop the study of user interface which we think was needed at this stage. In detail, we developed functions for generalization such as improving maneuverability and the enhancement of reusability. And we developed special functions to achieve the goal in the project such as distance measurement function, surplus soil calculation function and section function. These developments made it faster to build up new real-time simulation in another project.