An on-line e-learning tool using Unity has been developed for stakeholders to study planning regulations and solar architecture.In our system proposal, an on-line game engine, namely Unity is utilized as a 3d visualization tool that integrated GUI handler script, logic script and object handler script on an httpd server.The possibilities of On-line Game Engine has been verified for visualizing a building form automatically generated according to planning regulations.The planning regulation in Japan is designed and implemented on each land parcel, which is based on the zone restrictions of land use system.The usable space of a building can be generated according to the zone restrictions implemented in a parcel, which include the planning controls of high altitude, oblique line and so on.