Assume here are three polygon surfaces P,Q, R along with vertices specified by as: P: P1(1,1,1), P2(4,5,2), P3(5,2,5)

And as Q: Q1(2,2,0.5), Q2(3,3,1.75), Q3(6,1,0.5) R: R1(0.5,2,5.5), R2(2,5,3), R3(4,4,5)

By using the Area subdivision method, that of the 3-polygon surfaces P, Q, R obscures the continuing two surfaces? Let assume z=0 is the projection plane.

Solution: Now, we have z=0 is the projection plane and P, Q, R is the 3-Dimentional planes.

We apply initially three visibility decision tests that are (a), (b) and (c), to verify the bounding rectangles of all surfaces against the region boundaries in the xy- plane. By using test 4, we can find out whether the minimum depth of individual of the surrounding surface S, that is nearer to the view plane.