Wind Tunnels & River Current from The QuakeLab

The QuakeLab - http://www.in2nett.com/stevefu/QuakeLab

        TEXTURES:

        NONE

        ENTITIES:

        trigger_push

        WHAT TO DO:

        Build the tunnel system/water first. After this 'static' setup is
        built, you can then implement the trigger_pushes. Make a brush and
        resize it so that it covers the volume you want to affect. Designate
        this brush as a trigger_push and give it the desired pushing
        direction by setting its angle. Do not use an angle of 0 if that is
        the direction you want, use 360 instead.

        OPTIONS:

        You may need to fiddle with the alignment of trigger_push entities
        if you are making them interconnect (eg. a tunnel with a number of
        turns in it.) When you are making a winding wind tunnel, each push
        entity should overlap into the next one by perhaps 8 to 16 units.
        The best thing to do at the start of a wind tunnel (but it's not in
        the MAP file) is to make the tunnel, and assuming it is a vertical
        one protruding from the ceiling, make the pusher extend only as far
        as the mouth of the tunnel. This forces the player to jump and as
        soon as the player's head hits the entity, he will be 'tractor
        beamed' upwards. Otherwise, if your pusher entity extends to the
        floor, you run the risk of the player getting caught on the lip of
        the tunnel entry which ruins the effect.(this can happen in the demo
        MAP.) Hindsight is 20/20. :) Grenades are also affected by the
        pushers. This might give you some starting points...When making a
        wind tunnel with turns in it, the turns should be gradual, rather
        set at 90 degrees - there is the possibility of the player getting
        stuck on a corner.