How do I make a completely transparent window?

Hey everyone,

my situation is thefollowing: I have three panes in front of each other. The one in thevery front is smaller than the others. I would like to make a sort ofwindow in the size of this pane that goes through the two others (sothat when I render out the final image as a PNG there is a transparentcut-out there). Just making the pane itself transparent obviouslydoesn’t do the trick because the others behind it still show. Doesanyone have an idea how I could achieve the effect I’m looking for?

Cube on layer 1, plane on layer 2.
A layer 2 mask layer is used to cut out the shape of the plane. Background set to transparent


Attachments

mask.blend (92.8 KB)

Thanks. Layers seem like the solution to my problem in general but I’m using Blender Render and it doesn’t come out right. Could you perhaps explain in more detail how I would go about changing things?

Adjusted to use Blender internal renderer


To make background transparent go to Render / Shading and set alpha to transparent
Give the plane a material and in the Material / Shadow settings disable ‘Cast’ so it doesn’t cast shadows onto the cube object

Attachments

mask_BI.blend (92.8 KB)

It worked! Awesome thank you so much!