An image visibility based pre-processing method for fast ray tracing in urban environments

An efficient ray tracing method for propagation prediction along a mobile route in urban environments

“…Previous work by the authors has developed an efficient method of characterizing the space in which reflected and diffracted rays, emanating from virtual sources, can propagate as lit polygons, use of which accelerates the ray-object intersection test [Hussain and Brennan, 2016]. This paper presents a hybrid 2-D to 3-D ray tracing model that extends the previous work by reducing the active image tree for a given receiver point by mapping the lit polygons to a coarse grid superimposed over the environment.…”

“…Lit and shadow polygons for (a) reflection image and (b) diffraction image[Hussain and Brennan, 2016].…”

An Efficient Ray-Tracing Based Model Dedicated to Wireless Sensor Network Simulators for Smart Cities Environments

“…Fig.1(b)). This zone is thus too wide and contains some dark zones as in [60], [63]. To become exact, i.e.…”

“…More recently, the illumination zone concept was reused by [63]. Each illumination zone, called a lit visibility polygon, is associated with a dark visibility polygon corresponding to the part of the zone shadowed by one blocker (building).…”

“…In contrast to [60], [63], the VG used in this article is exact. There is no dark zone inside the illumination zones; i.e.…”