A target_spawner can be used for a number of things. What it actually does is makes an item of your choice appear at the location of the target_spawner. Any single item can be spawned. Even weapons and health. id didn't ever use the target_spawner for things like that though. They mainly used it to spawn gibs, insane people, and creatures. This entity is pretty simple once you figure out a few things.
There are two entities that must be used to get the target_spawner to work properly. There must be the actual target_spawner and some kind of entity that will actually trigger the target_spawner into working like a func_timer or a trigger_once.
Now for an example:
Lets make a trap that will drop soldiers into a pool of lava.
The first thing we need to make is the tube coming from the ceiling that will drop the soldiers into the lava and the actual pool of lava. Now we need to put a target_spawner inside of the tube coming from the ceiling. Now we need to specify what the target_spawner will spawn. This is the part that most people get stuck on. Instead of actually targeting a misc_insane entity you must set the target of the target_spawner to the name of the entity that you want to spawn. So therefore in this example we would set target=misc_insane.
Next you need to create a entity that will start the target_spawner. Lets give the target_spawner a targetname of lavapool. targetname=lavapool. Now let's use a func_timer to actually spawn the misc_insane. Set the target of the func_timer to the target_spawner. target=lavapool. Also be sure that you set the turn_on spawnflag for the func_timer. Unless you want to make it so you can turn it on with another trigger like a func_button. If you were to do this then you would just give the func_timer a targetname and target it with the func_button.
There are some key value pairs that you can set for a target_spawner to get some different effects. They are speed and angle. Speed is the speed that the item will come out of the target_spawner. If speed is not set then the item will be dropped. Angle is the direction that the item will be spawned and if speed is set then it is the direction the item will be thrown.
One of the most common uses of a target_spawner is to spawn gibs and those insane soliders. There are 3 types of gibs. misc_gib_arm, misc_gib_leg, and misc_gib_head. The names are pretty much self explanatory. Another entity that is commonly spawned on a few of the id levels is the misc_insane entity which is an insane solider.
There are many uses for a target_spawner. A trigger on one side of the level will spawn a creature on the other side of the level to surprise the player when he/she returns. You can even spawn health, weapons, and armor. Don't know what the use of that would be but I'm sure there are a few good ideas you guys can come up with.
As you can see target_spawner is a pretty simple entity to use. Just remember that you must have some sort of trigger to set off the target_spawner. Anything can be used...such as a trigger_once, func_timer, trigger_multiple, etc. It all depends on how you plan on using the target_spawner.
To understand the target_spawner more you can download the
[example .map]. Anymore questions then
please post to the discussion board.