Find the total Intensity at the centroid of a triangle defined by points pl(1,1,1), p2(0,2,1) and p3(0,0,1), illuminated by point light source of 0.5 intensity at (1,1,5). The viewer is at (1,2,5). Given parameters: ka = 0.7, kd=0.9, ks = 0.6, ns = 10 and ambient intensity is 0.1 [10]