AI Collision and Decorator behavior problems

Author: Jordan Rarrat
Posted on: 06/13/2025

Part 1: The Problem

This week I ran into a critical issue with our enemy AI’s melee attack system. I had set up a collision box on the enemy character meant to detect when the player enters melee range. However, during gameplay, the OnComponentBeginOverlap event was never triggered, which meant enemies were unable to detect the player for attacks. This was a major problem because without the ability to detect the player in close range, enemies just stood there even during attack animations.

Part 2: The Solution

After debugging the issue and verifying that the collision box was being set up correctly in C++, I realized that while the component existed, it was not correctly attached or visible in the Blueprint version of the enemy on the map. I adjusted the SetupAttachment() in the constructor and enabled overlap events by setting the collision mode to ECollisionEnabled::QueryOnly and using SetCollisionResponseToAllChannels(ECR_Overlap). I also made sure that SetGenerateOverlapEvents(true) was called and that the delegate was bound to a UFUNCTION() to avoid runtime binding errors. Once these were in place, the collision began firing as expected. Now the enemy can detect when the player enters the attack box and trigger damage logic properly.