February 18, 2019
Tower Defense Tutorial
Episode 18 – Selection
Youtube – How to make a Tower Defense Game (E18 SELECTION) – Unity Tutorial
By: Brackeys
Ep. 18
This tutorial focuses on creating “Selection” functionality, allowing the player to select a turret.
We started by adding World Space UI to an example turret prefab. This will provide us with “sell” and “upgrade” functions later. For now, we just need to set these things up so they will appear when a turret is selected. This involved more use of the Horizontal Layout Group component on UI objects, which consistently do not give me the same result as the tutorial, so I’ll need to look into those.
After setting up the UI, we got into the script for implementing the UI. We started by cleaning up the build manager so that the game doesn’t get cluttered in the situation where it tries to build turrets but also selects a turret on a node. We simply added a “SelectNode” method to the Buildmanager that sets a node variable to the selected node, but also sets turretToBuild to null. Likewise, we added a selectedNode = null; call in the SelectTurretToBuild method. This helps ensure we’re only doing one at a time in game.
We are actually just using this one UI object and moving it around and turning it on/off. Initially we created a new script, NodeUI, and placed that on this node UI system of objects, and gave it a simple method where it would move its position to the target.GetBuildPosition(). This was used instead of target.transform.position because that would give us the center of the node’s location, where as this gives us some other variation of the position that is more applicable (look into).
We also wanted to add some extra functionality, including turning off the UI if the player selects the turret again. This was as simple as checking if the selectedNode was in fact the node clicked on (again). This would then deselect the node, with the Deselect method, which just set selectedNode to null and disabled the nodeUI canvas.
SUMMARY
- Horizontal Layout Group does not work for me like it does in the tutorials. It may have been changed over Unity versions so I need to look into this.
- On a Canvas UI object, you can change the values of “Dynamic Pixels per Unit” and “Reference Pixels per Unit” in the Canvas Scalar component to make UI elements show up better depending on the scale you’re working at
- What does GetBuildPosition() do exactly?