When is it advisable to use a trigger instead of just a collider in game programming?

Using a trigger is particularly advantageous in scenarios where you want to detect overlaps without having the physical collision response that comes with standard colliders. In the context of a character sitting in a health zone to charge their energy, employing a trigger allows for a more seamless interaction that can continuously monitor the character’s state while they are within that zone.

In this case, the trigger can continuously apply effects (like restoring health or charging energy) as long as the character remains inside the zone, without causing any physical obstruction or movement alteration that traditional colliders would provide. This makes the interaction smoother and allows for more intuitive gameplay, such as visual feedback or gradual energy restoration while the player is in the designated area.

In contrast, scenarios like collecting items or detecting an enemy's position often involve immediate responses to collisions that might be more effectively handled by using standard colliders. Additionally, bouncing off surfaces generally involves physics responses; therefore, triggers would not provide the necessary interaction dynamics involved in these cases. Thus, using a trigger in this specific context optimally serves the intended design while keeping the gameplay fluid.