Entrance into heightmap - question

[ryanmccx1]

Hey all,

I have a question. We're using a heightmap for our top area of our level, but beneath is a subway system that has stairs that lead up into the top (i.e. through the heightmap). We can't figure out how to go about doing this. How do you put a "hole" in the heightmap so our stairs can lead straight through it? I've seen it done before so I know it can be done. Any advice?

[redbox]

http://img21.imageshack.us/img21/7792/visdfdf.jpg
?

[jlhill17]

Like redbox's image shows, just use the visibility tool on your UDK landscape. The "invisible" portions can be walked through.