Geometric modelling for real time flight simulator applications

Several geometric modelling methods are compared for use within real-time flight simulation systems. Algorithms are presented which give a rapid solution for simplified versions of the models. The algorithms are robust and are suitable for flight simulator applications. The aircraft geometric structure is modelled as connected cylinders and the range of motion and the position of the aircraft is quantised. The programs take account of geometric and obstacle constraints. Although the solutions are suboptimal due to the simplified models used, the calculation time is short. The static model of the aircraft environment is held in computer memory as solid polyhedra. This model may be updated as new objects enter or leave the area of the aircraft. Overlapping spheres are used to model flying objects or moving objects on the ground. In this form the model data can be accessed efficiently by flight planning algorithms. The approach is global and uses a 3D or 6D graph of quantised configuration space. The method can also be applied to the planning of automatic low-level flight path.