Great link and thanks for the explanation. So by using a deferred rendering algorithm you can reduces the complexity O(m+n), (m=number of surfaces, n=number of

Great link and thanks for the explanation. So by using a deferred rendering algorithm you can reduces the complexity O(m+n), (m=number of surfaces, n=number of lights) where the forward lighting path renderers have complexity O(m*n). The trade-off seems higher memory usage, not working well on older hardware and with anti-aliasing and transparent objects explains why many modern engines like Unreal 3 and IW engine don't utilize it.