Scripting Technique - Using Groups

After getting used to the basics of Igor scripting, there are many options to explore. One of them is the effective use of groups. Once I discovered this feature, I explored the possibilities.

Groups are basically named script blocks and are disabled by default. They are created by going to Tags... where you create variables or in a script block at the top of the dialog. There are responses that can be used in script blocks to enable and disable groups. Groups allow you to use the QueueCall response to a specified group. This is not where the power of groups lie. They can be used in much better ways such as enabling and disabling them. In this example, is one way of using groups for an interesting method of extracting Intel during a mission.

The goal is to allow the player to pick up the Intel at a certain location and have that specific player bring it to another location. We want to track who has the Intel and allow for other players to pick it up if the Intel carrier dies. By using groups, we can implement the checks required to see who has the Intel and whether to allow players to take the Intel from the body. We use ActorRef variables to keep track of the Intel carrier and the dead player carrying the Intel.

The first group is simple: it allows the player to get the Intel from the specified location. Note the bolded response that enables another group. This will allow the Intel Carrier Death Check responses to run if the event is triggered. We set the IntelCarrier variable to the player actor that is closest to the Intel location.

Group: Intel Objective Check
Comment:

Trigger Event:
A member of PlayerPlatoon is within 0 meter(s) of Intel Location.
Responses:
Display ((The owner of (The actor nearest Intel Location)) + " has the intel.") to all players for 5 second(s).
Set IntelCarrier to (The actor nearest Intel Location).
Enable the Intel Carrier Death Check script blocks.
Prevent this block from being reactivated.

Another simple group that checks if the player carrying the Intel is at Extraction. We disable the Intel Carrier Death Check group because the objective is complete and it does not matter if the player dies.

Group: <Default>
Comment:
Intel at extraction check
Trigger Event:
IntelCarrier is within 0 meter(s) of Extraction.
Responses:
Mark Objective 2 complete in the objective list.
Decrement Counter - Objectives Left.
Disable the Intel Carrier Death Check script blocks.
Prevent this block from being reactivated.

Our first named group. It is triggered by the death of the IntelCarrier. The wonderful part of using groups is it does not require much scripting to do the job. The first response will disable its own group and the second will enable the check to allow players to retrieve the Intel from the dead body. Neat, huh? Of course, we need to set the DeadCarrier variable to the IntelCarrier so we know who to check is near the dead body.

Group: Intel Carrier Death Check
Comment:

Trigger Event:
IntelCarrier has been killed.
Responses:
Disable the Intel Carrier Death Check script blocks.
Enable the Gather Intel from Carrier Check script blocks.
Display ((The owner of IntelCarrier) + " has died. Retrieve intel from the body.") to all players for 5 second(s).
Allow this block to be reactivated.
Set DeadCarrier to IntelCarrier.

Our second named group. It is triggered by a player coming near the location of the dead Intel carrier. This block can only run if the IntelCarrier has died in the first place. Once this block has run, we can disable this group and enable the Intel Carrier Death Check again. This sets the groups up so they enable and disable each other, allowing players to grab the Intel of each other's dead bodies until they all die.

Group: Gather Intel from Carrier Check
Comment:

Trigger Event:
A member of PlayerPlatoon is within 2.5 meter(s) of DeadCarrier.
Responses:
Disable the Gather Intel from Carrier Check script blocks.
Display "Intel recovered!" to all players for 3 second(s).
Set IntelCarrier to (The actor nearest DeadCarrier).
Enable the Intel Carrier Death Check script blocks.
Allow this block to be reactivated.

Using groups is a powerful feature of Igor scripting. It allows for recursive scripting, as shown here, meaning groups can enable and disable each other like a loop. A perfect way of handling dynamic situations such as the death of our Intel carrier. This can be advantageous over the QueueCall response because you can allow the script block to use a trigger event. Use your imagination and you may find other methods of utilizing the group feature.