The Tower Defense Starter Kit is finally getting a feature that I've wanted to implement for quite some time: Global Abilities. Along with Tower Abilities, this will be the other major new feature that will be introduced with the upcoming v1.4 update. Going forward along a similar route as the Tower Abilities mentioned in an earlier post [check it out here: Tower Abilities], I'm using a component based approach for the Global Abilities as well.
The major focus of the Global Ability implementation within the context of v1.4 update is to establish a system that can be easily extended through subsequent updates, while introducing the first ability 'Airstrike' to demonstrate the working of the system. With the Airstrike ability, the player can now unleash a series of explosive strikes at the targeted location. Mechanically, it functions similar to the Meteor Strike ability in Kingdom Rush, relying on a cooldown based activation instead of the Tower Points.
The new Global Abilities Array dynamically updates the list of available Global Abilities in the HUD, thus reducing the need to make changes to the HUD every time an ability is added or removed. As a result, the designer only has to handle the functional part when adding a new ability.
The new Airstrike Ability HUD elements
The Global Abilities use a new Targeting system that function separately from the default Grid Cell Detection logic. This targeting system does not interact with the grid based elements & conveys to the player if the focused actor is a valid platform for deploying the selected ability. Having the targeting reticule displayed on the target in world space helps convey the impact location & depth more clearly than the default cursor based reticule that is displayed on screen space.
And finally here is a short video preview of the Airstrike in action: [My video creation/editing abilities are really bad, but I think it will atleast serve to demonstrate what's mentioned in the post]
As mentioned earlier, this update aims to create a system that will make it easier to add more abilities. Hence more cool abilities will be making it into the toolkit in future updates.
For more details about the Tower Defense Starter Kit, check out the official Unreal Engine forum support thread at: https://forums.unrealengine.com/showthread.php?102675-Tower-Defense-Starter-Kit-Support-Thread