Invisable Platforms and People

[railduffer]

Could someone please tell me, or point me to a tutorial on Invisible Platforms. I can set the invisible part, and the blue pegs to guide the people. I don't see any people. When I click on the platform guide a box pops up on the lower left. Among stuff that probably has nothing to do with my set up, There are boxes showing what looks like times that have to be filled in, and a percentage (I assume density) of people walking around. OK, I do not know how to fill these boxes in, and the ending result. There is a tutorial on Steam, but it does not say anything about the box on the lower left, and how to fill it in.
Can anyone please fill me in on how to get people working.
Thanks