3.2.1. Locating Area of Interest on the 3D Modelled Map

The AOI can be represented with the sequence of *n* vertices {*v*1, *v*2, *v*3, ... , *vn*}. Each vertex *vi* has three co-ordinates values (*vx*(*i*), *vy*(*i*), *vz*(*i*)). Considering *vi* as the first vertex of the AOI, the next vertex to *vi* will be *vnext*(*i*), where *next*(*i*) = *i*(*mod n*) + 1. The edge *ei* connecting two vertices *vi* and *vnext*(*i*) has length *li*, where *li* = 5 5 <sup>5</sup>*vi* <sup>−</sup> *vnext*(*i*) 5 5 <sup>5</sup>. The AOI can contain many obstacles and no-Fly Zones (NFZ) of varying geometries. The AOI boundary is set of collision free vertices and edges. In some cases, the AOI vertices, edges or both can intersect with obstacles as shown in Figure 3.

**Figure 3.** Different obstacles' intersections with the area of interest boundary.
