Handling environment queries within a behavior tree

We are now ready to implement the behavior tree, which, as you will see, shows some similarities with the BT_GunnerDummy asset; the only difference is the way we get possible targets. For this reason, we will be using the same Blackboard as BT_GunnerDummy. So, without further ado, open BT_EQSGunnerDummy and, in the Details panel, set the Blackboard Asset attribute to BB_GunnerDummy.

Now, focus on the behavior tree graph and do the following steps:

1. Add a Selector node to the ROOT node and name it Root Selector.
2. Add a Sequence node to the Root Selector node and name it Shoot Sequence.
3. Add a Blackboard decorator to the Shoot Sequence node and name it Has Ammo?. In the Details panel, do the following:
   • Set the Notify Observers attribute to On Value Change
   • Set the Key Query attribute to Is Not Set
   • Set the Blackboard Key attribute to NeedsReload

   The graph so far should look like the one shown in Figure 11.3:

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