making a non walk through portal

i have book looking for an answer for 3 days now but all i managed to find is that it is very easy with unity pro using the texture render.

i have unity pro, but i sill didn’t figured it out.
please can any one point me to how do i start making the portal.

what i need is a tome thing like that
YouTube portal example
but without the ability to go through the portal, all i need is look through it.

Wow, that’s impressive. Assuming you know how to make the portal itself, (Because I sure as hell don’t.) a quick and dirty way to prevent things from moving through it would be to put a correctly scaled cube in front of it and disable, or remove, the ‘Mesh Renderer’ component. Thus you make an invisible wall.

This is what you want. Works in Unity Standard.