Interactive Tin Modification with a Cutting Tool

We present an interactive method of surface modelling using a cutting tool. Terrain modification is an important part of spatial decision support systems for various applications, including landscape modelling, civil engineering and flood management. We describe an algorithm and demonstrate several examples of use the method on different surface features. This approach is based on the ability to manipulate a cutting tool – a “knife” – within the terrain model space, and calculate the intersection points of the knife with the surface. Various issues are discussed, including the handling of vertical cuts and points on the knife edges. This method has been implemented in a real-life simulation system and proved to be appropriate for terrain modification simulation process.