NALIG: A CAD system for interior design with high level interaction capabilities

In the last few years, CAD systems have been evolving from simple drafting tools to much more complex solid modeling environments. Nevertheless, experience has shown that effective use of such systems relies on the characteristics of their user interfaces: the user should have the possibility of describing a particular scenario in full detail or giving the system only a raw description of it. The authors describe NALIG, a system able to understand and reason about high-level descriptions of spatial scenes. The user interacts with the system by using a simple natural language fragment that is expressive enough to describe complex configurations of objects. NALIG replies by drawing on the screen an image mirroring its own understanding of the scene that has been described. The comprehension process involves various forms of common-sense reasoning carried out at two different levels of abstraction. This has required the integration of different AI techniques (e.g. natural language understanding, spatial reasoning and default reasoning)