more transparency questions

how would i make a plane that is transparent, yet if if part of an object goes behind it, the part thats blocked by it will disappear?
am i making sense? :confused: i’ll try to post sime pictures of what i mean.

heres what i mean: theres a plane in front of a cube, the plane is supposed to be transparent but isnt here for illustrative purposes:

here is a mockup i made of what i want (sort of):
as you can see, the area where the plane obscured is as if there is nothing there, except for the light gray area on the left, which should also be transparent. i messed up some where in the mockup, but i hope u get the point.
any way to do this?


Give the plane a material that has alpha 1.0, and ENV selected.

rawpigeon: thanx, this is exactly what i needed!