added cone geometry, implemented fov visualization

geometries/REGION_TYPE.m

@@ -8,6 +8,7 @@ classdef REGION_TYPE
         DOMAIN (1, [0, 0, 0]); % domain region
         OBSTACLE (2, [255, 127, 127]); % obstacle region
         COLLISION (3, [255, 255, 128]); % collision avoidance region
+        FOV (4, [255, 165, 0]); % field of view region
     end
     methods
         function obj = REGION_TYPE(id, color)