UnityLearn - Beginner Programming - Swords and Shovels: Character Controller and AI - Pt. 01 - Overview and Character Controller

Novemeber 21, 2019

Beginner Programming: Unity Game Dev Courses

Beginner Programming: Unity Game Dev Courses

Unity Learn Course - Beginner Programming

Overview and Character Controller

Navigation and Animation Review

This part of the tutorial just gets you familiar with the NavMesh setup they have and the animator they are using on the player character. Some of the items are a bit off since they are using an older Unity version (2017), like where the Navigation tab is located (it is now under Window -> AI).

The player character animator has a blend tree that holds a speed parameter. This parameter appears to determine how much to blend between an idle animation and a running animation, as well as how fast the animation plays.

Controlling Motion with C# and Unity Events

This tutorial portion started with adding a NavMesh Agent component to the Hero character to have it interact with the baked NavMesh in the scene.

The next step was to edit the MouseManager class to actually move the character according to its NavMesh Agent and the created NavMesh. This would require a reference to the NavMesh Agent component. They did not want to use a public field (as this creates a dependancy that can lead to issues down the road), so they turned to making an event.

They needed to create this event, which they did so as a new class within the MouseManager script, but outside of the class. This was done in the following way:

[System.Serializable]
public class EventVector3 : UnityEvent { }

The base class UnityEvent lets it send vector3 information through an event.
They then created a public field of the type EventVector3 named OnClickEnvironment. This was then used to do the following:

if (Input.GetMouseButtonDown(0))
{
OnClickEnvironment.Invoke(hit.point);
}

The public field created a box within the inspector similar to UI events in Unity. You could drag an object in as a reference, and select a component and method to call when that event happened. In this case they used the Hero object, and called the NavMeshAgent.destination method.

Synchronizing Animation with Motion

They start by simply referencing the NavMeshAgent speed and passing that value into the animator's speed parameter. They then begin to alter the NavMeshAgent component's properties to fine tune the movement to feel better to play with. They significantly increased the Speed, Angular Speed, and Acceleration, and turned off Auto Braking. This felt much better, but led to an issue where the player would run back and forth near their destination.

The issue is caused by turning off Auto Braking and not having a Stopping Distance. I assume since the character has trouble "perfectly" reaching the value of its given destination, the Stopping Distance of 0 means it will keep trying to get there even though it cannot.

Setting the Stopping Distance to 0.5 fixed this issue. This allows the agent to stop moving once it is within 0.5 units of the given destination. There was still a strange issue where the character would move slowly around stairs, but they said they would cover this issue.

Handling the Passageway

This portion deals with adding code to allow the character to traverse the special passageway section of the level. The passageways have unique colliders to inform the cursor that a different action should take place when they are clicked. These colliders also have direction, which will be used to determine which way to move the character through the hallway.

They then go back to the MouseManager to show where the cursor is detecting the unique collider (currently just to swap the mouse icon with a new icon). This is where they add extra logic that if door is true (a doorway has been clicked) that they want to grab that object's transform and move a fixed distance (10 in this case) in that object's z-direction. This is why the collider's orientation is important.

This setup seems very bad to me. This only works for passageways that are all exactly the same distance since the value is hard coded in. You can still click on areas between the passageway entrances, so the character just gets awkwardly stuck in the middle with the camera pressed up against a wall. There is no limitation when taking a passageway, so the player can click again midpassage and alter their character trajectory which can be weird or buggy.

I think I would prefer a system that somehow links the two passageway entrances so that no matter where they are, when the player clicks one they will enter it and come out of the other one (use their transform with some offset). Player input should also be limited somehow during the passage because there is no reason to do anything else within the passage, this only allows for more errors.

Note:

The MouseManager uses a lot of if/else conditional statements, and from the previous lessons, I think it could possibly benefit from having a small state machine setup. While I think it is just on the edge of being ok in its current setup, the Update method for the MouseManager is already looking a bit bloated and any more complexity may start to cause issues.

SUMMARY

I think this tutorial was mostly focused on just getting you used to finding and using some different features of Unity, such as NavMesh and the Animator. Nothing here seemed to be that deep or well done, so it felt very introductory. Getting a refresher on NavMesh agents was definitely useful at least, and working with animation never hurts.