I'm not sure what you call them, i guess lifts or rising platforms. They stay in the ground until you step on them, then they go up, and they have a shiny pillar that pushes them up. Yeah those things.

I want one.

I've searched many places, but I can't find a prefab, a tutorial, nothin. But lots of player-made maps have them, so there must be SOMEONE out there who could help, please?

Thanks in advance!
(my first map is almost done)

The piston itself is usually a few cylindrical brushes that are either parented to a func_door, or a func_door themselves. The lift is a model found in with the rest of the portal models.

Once you have the lift in its starting position, and the pistons sized right to extend as far as you need, you need three brushes, and it'd be a good idea to have a logic_relay if you have multiple pistons.

Your first brushes is a glass brush about 2-4 units thick just inside the lift model. Then you need a brush textured with playerclip in about the same spot(not absolutely needed, but it was that way in the official maps) and then a trigger brush, trigger_multiple, about 8-16 units high off the top off the lift model. Parent the lift model, trigger, playerclip and the glass brushes to the top piston. Now add the outputs to the trigger that are something like this:

OnStartTouch - piston_func_door - open
OnEndTouch - piston_func_door - close

If you have multiple pistons, it'd probably be a good idea to add the outputs to a logic_relay. You'll have to experiment with the timings for opening/closing the pistons if theres more than one.

Just a rough idea of what it should be, off the top of my head. Hope it works

Since it took me ages to find out, and no one has mentioned it the pistion is textured such that it that won't actualy appear correctly (just black) untill you've built your cubemaps, search for 'lift' with the portal filter in the texture browser to find it.

Thanks for the info! I'll give that a shot.

But then there's the sound effects to worry about...
Boy, I sure would love a prefab or even just a lift from a map file that I could copy and paste. Why didn't valve just include standard portal prefabs with hammer???? Argh, make it easier for us to build the levels in our heads.

Don't get frustrated Hammer gives us all of the tools we might need to give life to our visions, and if Hammer doesn't have it we can still create it. I'd suggest you go ahead and study the list of entities, that way whenever you feel like trying something you know that some entity or conbination of them will make it work, lifts and what not.

Farragar wrote:
Since it took me ages to find out, and no one has mentioned it the pistion is textured such that it that won't actualy appear correctly (just black) untill you've built your cubemaps,

I think that would be common knowledge, since cubemaps are what handles the reflections and without cubemaps nothing will reflect.