Well u must create a region where ur going to "enter" to the other map, this is a trigger example: Events: A unit enters "region" (region that u choosed) Conditions: None Actions: Fade filter: Fade out over 2 seconds using white mask Wait 2 seconds Set level to: (The other map that ur going)
PS: The fade filter and the wait actions arent obligatory but the filter will be used to "close" the sight of the player and wait is used to delay the other action so that the actions arent made to fast.
I hope this is usefull ah and about game cache well I dont know but look in www.thehelper.net I think there is a tutorial about game cache and other usefull stuff