for your ai this:

(script startup script_name
(sleep_until (volume_test_objects trigger volume (players)) 10)
(game_save_totally_unsafe)
(ai_place encounter/squad)
)

there is also a checkpoint in there

edit: as for BSP switch:

(script startup bspswitch
(sleep_until (volume_test_objects trigger volume (players)) 10)
(game_save_totally_unsafe)
(switch_bsp 1)
)

replace coloured text with your trigger volume names, encounter/squad and BSP names
Edited by jackotheblah on Mar 16, 2011 at 04:13 AM

No need for a script, simply place the trigger_volume in Sapien, name it, then save and open the scenario in Guerilla. Scroll down until you see the "bsp switch trigger volumes" section ("volumes" is usually cut off by a dropdown box). Now just add one and fill in the appropriate information.