Add animation to your game

In this tutorial, you’ll add animations to your game, whether you’re working in 2D, 3D, or decided to try both. By the end, your project will have animated elements, just like the example projects shown below.

3D game

If you’re doing the 3D game, you’ll create an animated enemy character to replace the current basic enemy shape.

2D game

If you are doing the 2D game, you'll add animations to the enemy and player sprites.

Your game design document (GDD) is still evolving, so take a moment to review it with a focus on character and object movement.

Animation shapes how your game feels moment to moment. A horror game might rely on slow, unsettling motions, while a fast-paced arcade game uses snappy, exaggerated animations.

Now, think about the animation style that suits your project, whether you’re building in 2D, 3D, or both.

Ask yourself the following questions:

• What core actions must be animated — movement, attacks, pickups, damage, death, UI reactions?
• How will animation support player feedback — for example, squash and stretch, anticipation, or hit reactions?

Take some time to review the assets provided in the UCU Game Developer package that you downloaded and imported earlier.

If you haven’t downloaded and imported those assets, you can do that now.

In the asset pack, you can browse the Prefabs > Characters folder, which contains a few character options for you to work with. Each character comes with at least a walk/run animation. Feel free to use any of these characters. You’ll have an opportunity to search for other characters in the Asset Store in a later tutorial.

2D game

Most sprite sheets come with animation frames included. If yours didn’t, you'll have to create animations for your sprites and export those as new sheets.

This is beyond the scope of this course, but you can look at generators like these:

• Voidless.Dev - AI Pixel Art Generator
• Universal LPC Sprite Sheet Character Generator
• Universal Sprite Creator YouTube Tutorial

You can also do it manually using software like Adobe Animate or Asperite.

You can even create sprite animations from 3D models using software like Blender.

Create an animated enemy character (3D)

We’ve provided a few sample characters to demonstrate how you can add animated enemies to your game. In the following steps you'll learn how to do that.

We encourage you to repeat these steps with your own character once you understand the process.

To add the an enemy model to your game, follow these instructions:

1. Drag your selected character model from the Prefabs > Characters folder onto the Enemy GameObject to add it as a child GameObject.

The Enemy GameObject already controls the movement on the NavMesh, so any child GameObject will move along with it.

2. Change the scale and position of your selected character model as you see fit.

The Enemy GameObject will still show as a cube GameObject in the scene.

3. Select the Enemy GameObject, and in the Inspector window, disable the Mesh Renderer component to hide it.

4. Test the game.

You’ll notice that the new character is chasing the player as before, but the character stays in the default T-pose. Let’s add the provided animations to the character.

Adding animations to the enemy character

To add animation to your selected character model mode, follow these instructions:

1. Navigate to the Assets > Animations folder, right-click in the Animations folder, then select Create > Animation Controller. Name it “EnemyAnimation”.

2. Select your chosen character model in the Hierarchy window, then, in the Inspector window, drag the newly created Animator Controller to the Controller property box of the Animator component.

We’ve provided a few animations for your selected character model character, but they still need to be assembled and assigned to be used.

3. From the main menu, select Window > Animation > Animator to open the Animator window.

4. Navigate to Assets > Animations > AnimationClips, locate the idle animation for your character, in this case the Mr.Crab@Idle animation, and drag it into the Animator window.

If there’s no Idle animation, select the walk or run animation instead.

This will set the idle animation as the default state. If you test the game now, you'll see that the idle animation runs once, then stops.

5. In the Project window, select the animation clip again. In the Inspector window, select the Animation tab, and then enable Loop Time.

This will ensure that the idle animation plays continuously. Unfortunately, the idle animation is the only animation that plays, even when the character is moving. Let’s fix that.

6. Navigate to Assets > Animations > AnimationClips, locate the walk animation, and drag it into the Animator window.

7. Right-click the Idle animation, select Make Transition, and select the Walk animation to link the two.

8. In the Animator window, switch to the Parameters tab and add a new float parameter. Name it “speed_f”.

You’ll use this parameter later in a script to toggle the transition between the idle and walk animations.

9. Select the transition line between the Idle and Walk animations and in the Inspector window, select the Add (+) button under Conditions to add a new condition.

10. Ensure that the new condition is set to speed_f, Greater and 0.

This means the transition will happen whenever the speed_f parameter is set to something bigger than 0.

11. Create another transition, this time from the Walk animation to the Idle animation.

12. Select the new transition line, and in the Inspector window, add a condition set to speed_f, Less and 0.05.

This will let the animation transition back to idle when the enemy is not moving.

Now you need to make sure that the transition will happen when the state of the enemy changes and not only when the animation has played all of its frames.

13. Select the transition line from Idle to Walk and disable Has Exit Time.

14. Select the transition line from Walk to Idle and disable Has Exit Time.

The Has Exit Time property determines if a transition from one animation state to another should wait for the first animation clip to finish or if it can transition at any point based on other conditions being met. In gameplay, responsiveness is critical. If a player provides input to make a character walk, they expect the action to be immediate. If Has Exit Time is enabled, the transition to the walk animation might have to wait for the idle animation to finish its current loop, leading to perceived input lag.

15. Navigate to Assets > Animations > Mr.Crab, select the Walk animation, and just like you did for the Idle animation, enable Loop Time.

Update the EnemyMovement script

To update the EnemyMovement script to reflect the new animations you just added, follow these instructions:

1. Open your EnemyMovement script and add a new private Animator variable.

private Animator anim;

2. Add the following code to the Start function:

private void Start()
    {
        //Get the nav mesh agent component
        navMeshAgent = GetComponent<NavMeshAgent>();
        //Get the animator component
        anim = GetComponentInChildren<Animator>();
        //Set the value of speed_f
        if (anim)
        {
            anim.SetFloat("speed_f", navMeshAgent.speed);
        }
    }

This code retrieves the Animator component from any child GameObject. Then, if the Animator component exists, it sets the speed_f parameter to match the speed of the agent. This means that the animation clip’s speed will be proportional to the speed the enemy is moving, which is perfect.

Now, the enemy’s walking animation should play when it moves, but the enemy character will continue its walking cycle after it has stopped when it catches the player — this will look very strange.

To set the animation back to idle, you need to set the speed_f variable back to 0 when the lose condition is triggered.

3. Add the following line to your PlayerController script inside the if (collision.gameObject.CompareTag("Enemy")) section of the OnCollisionEnter function:

//Set the speed of the enemy’s animation to 0
            collision.gameObject.GetComponentInChildren<Animator>().SetFloat("speed_f", 0);

The complete function should look like this:

private void OnCollisionEnter(Collision collision)
 {
  if (collision.gameObject.CompareTag("Enemy"))
  {
    // play explosion fx
    Instantiate(explosionFX, transform.position, Quaternion.identity);

    // Destroy the current object
    Destroy(gameObject);

    // Set the text to "You Lose!"
    winText.text = "You Lose!";
    AnimateText();


    // play explosion sound
    collision.gameObject.GetComponent<AudioSource>().Play();

    // Set the speed of the enemy to 0
    collision.gameObject.GetComponentInChildren<Animator>().SetFloat("speed_f", 0);
  
  } 
  
}

Add animations to your sprites (2D)

Prepare the sprite sheet

To set up the sprite sheet so that it can be animated, follow these instructions:

1. Import your sprite into your Unity project and select it in the Project window.

2. Change the Sprite Mode in the Inspector window from "Single" to "Multiple".

3. Adjust other settings if needed (for example, set the Filter Mode property to Point (no filter) for pixel art and the Compression property to None for best quality).

4. Select Apply to save the import settings.

5. Open the Sprite Editor by selecting the Sprite Editor button in the Inspector window.

If the button is greyed out, ensure the 2D Sprite package is installed via the Package Manager.

6. Open the Slice dropdown menu in the upper-left corner.

7. Select a slicing Type:

• Automatic: Best for irregular sprites with spacing between them.
• Grid By Cell Size: Ideal for evenly distributed sprites of a standard size. Enter the pixel dimensions of each sprite (for example, 32x32).
• Grid By Cell Count: Useful if you know the number of columns and rows.

8. Select a Pivot point (for example, Center or Bottom Left) for the individual sprites.

9. Select the Slice button.

10. Review and refine the slices.

You can manually adjust the bounding boxes of individual sprites, rename them, or change their Pivot points if needed.

11. Apply changes by selecting the Apply button in the upper-right of the Sprite Editor window.

12. Close the Sprite Editor and return to your Project window.

The individual sub-sprites will now appear as child sprites of the main sprite sheet asset and can be dragged into your scene or used in animations.

You can learn more about this in the Introduction to Sprite Editor and Sheets tutorial and the Sprites documentation.

Create the animations

To create the keyframed animations, follow these instructions:

1. Open the Animation window by selecting Window > Animation > Animation.

2. Select the sprite you want to animate.

Make sure it’s the actual GameObject that contains the Sprite Renderer component, and not a parent GameObject.

3. In the Animation window, select the Create button to create a new animation clip and name it something relevant.

4. Drag the individual sprite frames you prepared earlier from the Project window directly into the timeline.

Unity will automatically place them in sequence.

5. Select Play in the Animation window to preview the animation.

If it looks too fast or too slow, adjust the Samples property value in the upper-left of the Animation window until you get the timing you want.

If the Samples property isn’t visible, activate it by selecting the More (⋮) menu in the upper-right corner of the Animation window and enable Show Sample Rate.

Once enabled, the Samples property will appear next to the clip name.

Unity automatically creates an Animator Controller when you save the clip.

6. Select the sprite GameObject and look in the Inspector to confirm that an Animator component and controller have been assigned.

7. To make the animation loop (or not), select the animation clip in the Project window, then in the Inspector window, enable or disable Loop Time depending on what the animation should do.

8. Test the animation in Play mode to ensure it behaves correctly in-game. Adjust clip settings, frame order, or sample rate as needed.

If you want to develop your skills further, explore new concepts, or improve your project, check out some of the optional activities below.

These activities are entirely optional, so if you’re not interested, no problem – just skip this step. We do recommend attempting it in order to get the most out of this learning experience. Good luck!

Easy: Add additional animations to scene elements

Your characters aren’t the only objects that can be animated in the scene. Try using Unity’s built-in animation tools to animate other objects. You could add a moving platform that adds new gameplay mechanics, or you could do more aesthetic animations like giving static environmental objects a subtle bounce or sway.

In this tutorial, you created animations to add some life and dynamics to the game. In the next tutorial, you'll learn how to customize the look and feel of your game with materials and shaders.