A geometrical framework for solving sunlighting problems within CAD systems

We propose a framework based on integral geometry that makes it possible to express and solve most geometrical sunlighting problems within CAD systems: the direct problems for assessing sunlighting in a scene and the inverse ones for achieving sunlighting constraints in a design context. The heart of our method is the sunlighting volume that we denote Π(P, T). We describe this notion and we show how to implement it in an architectural and urban design process.