Tower Defense Tutorial – Brackeys – Ep. 20

February 24, 2019

Tower Defense Tutorial

Episode 20 – Sell

Youtube – How to make a Tower Defense Game (E20 SELL) – Unity Tutorial

By: Brackeys

Ep. 20

This tutorial focuses on implementing the “sell” functionality to go along with the sell UI button we have. We are also going to setup an upgraded version of the missile launcher and the laser beamer turret.

The upgraded versions of the missile launcher and laser beamer turret were just upscaled versions with some buffed stats and different material colors. These were set in the Shop TurretBluePrint editor sections as well.

For the selling function, we wanted to add that to our Node script. However, since we just wanted to code something standard to create the sell value of a turret, we ended up going to the TurretBluePrint to create this calculated sell value. This was done because we can now just reference the TurretBluePrint class anytime we want the sell amount, and if we ever want to change how that is calculated, we can just change it in one place instead of looking around for everywhere it is used. In TurretBluePrint class, we simply added a method, GetSellAmount, that returns an int that is just the cost divided by 2 for now. This method can now be referenced in the Node script to get that sell value.

The UI system is very easy to add functionality to. The main UI object holds the central script that keeps track of what we have selected and call methods on that node specifically, as well as containing all the basic UI methods (such as on click events). It’s very easy to know that anything dealing with altering a node goes through this script. It also keeps a lot of our UI functionality organized in one location.

SUMMARY

• If you are using a variable multiple times that needs calculated, but may want to alter this calculation throughout the design process, it is good to have this done in one location as a small helper method and then reference this method when you want that value. That way you only have to change the calculations in one place to change them globally.