Does anyone know what entity type a combine energy ball falls under/if you can name them? I'm experimenting with them to see if I can use a trigger to kill them, with the use of a filter if needed.

There are combine energy balls (from Half-life), and Portal Energy Pellets. The entity is a prop_energy_ball, just look at any pellet catcher instances since they use a trigger to detect the pellet. You can send three inputs to them: Kill (instantly vanishes), Explode (which makes a camera shake effect + shockwave) and BallCaught (similar to Kill, but disables the point_energy_ball launcher that fired it and also triggers the OnBallCaught output on that launcher).

If you're referring to the balltype keyvalue, I believe it's not functional in portal.

Also, if you want to kill them after a certaint time or something use a logic_register_activator to remember the entity so you can trigger it later. Put a trigger_multiple right in front of the launcher, and use that to register the pellet. (Enable OnPostSpawn, disable OnStartTouch).

The classname you need to filter is prop_combine_ball or prop_energy_ball depending on the entity you used for the launcher. The easiest way to filter for them, though, is to use a filter_combine_ball_type (with the type set to Launched from Point_combine_ball_launcher), which will detect both.

Also, if you want to kill them in a more interesting way, use the input Explode.

All good suggestions! Thanks!

For anyone that may have been wondering, I'm trying to implement a function into either FR's matter inquisition field, or Ultiman's energy dissipation/distabilization field (or both) that makes the combine balls explode on impact. I've not seen it done before, and it could potentially lead to some interesting puzzles

If it helps, I implemented Mevious's Rexaura positron orbs in Portal 2 using a trigger_multiple with a filter_combine_ball_type. OnStartTouch !activator Explode.