Hairston Cemetery Kismet Notes
Any gameplay functionality done in Gears of War is controlled through Kismet, a visual node based scripting program in the Unreal engine.
Basic Kismet Functionality
One of many powerful tools used by designers in Kismet was something called level streaming. With this a designer could create multiple sub-levels that acted as layers. Each sub-level could have a variety of different objects in them and be layered on top of each other. Objects on one sub-level would appear in the exact same position when placed on top of another sub-level.
Hairston Cemetery had several different sub-levels layered on top of each other through Kismet. When the level started the persistent level loaded first and then all other sub-levels were loaded on top of the persistent level. These sub-levels could then be loaded, unloaded or reloaded based on the needs of the designed level.
The randomly looping environmental sound effects were created by linking play sound nodes into delays that were then linked back into the play sound node. A random float number value was set to the delay node's duration to give a random amount of time before the sound activated again. (See details on Theme/Mood Notes)
Proper Checkpoint Activation
Properly activating a checkpoint in Gears of War requires the level to be fully restored to the exact same state it was before the checkpoint was activated. Checkpoints could reload any number of sub-levels and number of times needed, but the persistent level can't be reloaded. Whenever something is activated in the persistent level it will not be reactivated after a checkpoint.
My first major problem occurred when players sealed the second emergence hole and reloaded the second checkpoint. Re-streaming the second sub-level caused the second emergence hole to revert back to its original state at the start of the level, making it appear like it had never opened.
I solved this by placing a fake sealed emergence hole right under the second emergence hole and hid it when the level started. When the second emergence hole was sealed and the second checkpoint activated, the fake emergence hole would be revealed.
The third problem occurred when players reloaded the first checkpoint and the fake emergence hole appeared before the player could seal the second emergence hole. So reloading the first checkpoint resulted in enemies climbing through the mesh of the fake emergence hole to enter the level.