Creating 2D Animations in Unity

To create 2D animations in Unity, developers can use the built-in Animation window and the Unity Animator component. Here's a step-by-step guide to get started.

Setting up The Project

Open Unity and create a new 2D project or open an existing one.
If starting a new project, set the project's template as 2D.

Importing Sprite Assets

The sprites can be created within Unity by using the Sprite Editor or imported from external image files such as PNG or JPEG.
To create sprites within Unity, go to the Assets menu, select Create, and choose either Sprite or Sprite Renderer. It's then possible to draw or import the sprite artwork.

Configuring Sprite Animation

Once the sprites are ready, select the sprite asset in the Project window.
In the Inspector window, make sure the Texture Type is set to 'Sprite (2D and UI)'. If not, change it to 'Sprite (2D and UI)'.
Click on the sprite asset in the Project window to open it in the Sprite Editor.
Use the Sprite Editor to define the individual frames of the animation. The sprite can be split into multiple sub-images if needed. The editor also allows modifying the pivot point for each frame to control the position of the sprite.
Save the changes made in the Sprite Editor.

Creating Animations Using The Animation Window

To open the Animation window, go to 'Window -> Animation'.
In the Animation window, click on the Create button to create a new Animation clip.
Select the animation clip in the Project window, and its properties will appear in the Inspector window.
In the Inspector window it's possible can set the animation clip's length, sample rate, and other properties.
To create keyframes, move the play head in the Animation window to a specific time and modify the sprite's properties (e.g., position, scale, rotation, etc.) in the Scene or Hierarchy window.
Add keyframes at different times to create a smooth animation. Unity will automatically interpolate the values between the keyframes.

Setting Up The Animator

Select the sprite object in the Scene or Hierarchy window.
In the Inspector window, click on the Add Component button and search for "Animator" to add the Animator component to the object.
Click on the Create button in the Animator component to create a new Animator Controller asset.
Assign the newly created Animator Controller to the Animator component's Controller field.

Configuring The Animator Controller

Double-click on the newly created Animator Controller asset to open it in the Animator window.
In the Animator window, there's an Animator Controller graph, which represents the flow of animations.
Right-click in the Animator window and select 'Create State -> From New Clip' or 'From Sprite Renderer' to create animation states.
Drag and drop the previously created animation clips in the Animation window onto the respective animation states.
Create transitions between animation states by clicking on a state and dragging the arrow to another state. It's possible to adjust the conditions for transitioning, such as time, parameter values, or events.
It's possible to add parameters to control the transitions, such as bools, ints, or triggers. For example, there can be a bool parameter named "IsRunning" that triggers a transition from an idle animation state to a running animation state.

Playing The Animations

Select the sprite object in the Scene or Hierarchy window.
In the Animator component in the Inspector window, drag the created Animator Controller asset onto the Controller field.
Press the Play button in the Animation window to test and preview the animations.

Controlling Animations Programmatically

Controlling animations programmatically requires to access the Animator component from the script.
In the script, create a variable of type Animator and use 'GetComponent<Animator>()' to get a reference to the Animator component attached to the sprite object.
It's possible to then use the Animator's functions and properties to trigger transitions, set parameter values, or control the playback of the animations. For example, calling the animator.SetBool("IsRunning", true) will trigger the running animation.

using UnityEngine;

public class AnimationController : MonoBehaviour
{
    private Animator animator;

    private void Start()
    {
        // Get a reference to the Animator component
        animator = GetComponent<Animator>();
    }

    private void Update()
    {
        // Check for input or condition to trigger animations
        if (Input.GetKeyDown(KeyCode.Space))
        {
            // Trigger a jump animation
            animator.SetTrigger("Jump");
        }

        float moveInput = Input.GetAxis("Horizontal");
        animator.SetFloat("Speed", Mathf.Abs(moveInput));

        // Check if the character is grounded
        bool isGrounded = IsGrounded();

        // Set the "IsGrounded" parameter in the Animator
        animator.SetBool("IsGrounded", isGrounded);

        if (isGrounded && Input.GetKeyDown(KeyCode.C))
        {
            // Trigger a crouch animation
            animator.SetBool("IsCrouching", true);
        }

        if (isGrounded && Input.GetKeyUp(KeyCode.C))
        {
            // Stop the crouch animation
            animator.SetBool("IsCrouching", false);
        }
    }

    private bool IsGrounded()
    {
        // Implement your own logic to check if the character is grounded
        // For example, you can use raycasting or collision detection
        // and return true if the character is touching the ground
        // and false otherwise.
        return false;
    }
}

Conclusion

This is a basic overview of creating 2D animations in Unity using the built-in tools. Unity also supports more advanced techniques like using sprite sheets, inverse kinematics (IK), and scripting custom animation behaviors. Explore these options based on the specific requirements and the complexity of the animations in question.

unity unity2d sprite animation animator play guide beginner tutorial getcomponent project new 2d window how-to step-by-step theory