Game Frameworks  
Lecture 05: Sprites and Animations in Unity  
Edirlei Soares de Lima  
Unity Sprites  
Sprites are 2D Graphic objects (images).  
If the project mode is set to 2D, all imported  
images are automatically set as a Sprite.  
The Sprite Renderer component renders the  
Sprite and controls how it visually appears in  
a Scene.  
Unity Sprites  
Assets for this class:  
Important: import only the sprites folder “2DPlatformerPack”  
Replace Placeholder Sprites  
To change a placeholder sprite, click on it in the Scene View  
and then edit the Sprite property in the Sprite Renderer  
Adjust camera size:  
Sprite Animations  
To create a new animation clip, drag and  
drop the animation sprites into the scene.  
Save the animation clip.  
The sprite can be removed from the scene (the  
animation will be assigned to the existing player  
An “Animation Clip” and an “Animation  
Controller” will be created.  
Sprite Animations  
To assign the animation to the existing player sprite, add an  
“Animator” component to the Game Object.  
Select the Animation Controller previously created in the Controller  
Then, test the animation playing the game.  
Animator Controller  
An Animator Controller can arrange and maintain a set of  
Animation Clips and associated Animation Transitions.  
Even sprites that have a single Animation Clip must use an Animator  
The controller has references to the animation clips and manages the  
various animation states and the transitions using a State Machine.  
Animation State Machines  
Actions (animations) are associated  
with a state.  
Each transition leads from one state  
to another, and each has a set of  
associated conditions.  
When the conditions of a transition  
are met, then the machine changes  
state to the transition’s target state.  
Each character/object is controlled  
by one state machine and they have  
a current state.  
Animation State  
A state represents an animation.  
Each state contains an individual animation sequence which will play  
while the character is in that state.  
Main properties:  
Motion: animation clip assigned to the state.  
Speed: default speed of the animation.  
Animation Transitions  
Animation transitions allow the state machine to switch from  
one animation state to another.  
The transition defines under what conditions it should occur.  
Main properties:  
Has Exit Time: defines that transition that does not rely on a  
parameter. Instead, it relies on the normalized time of the  
Conditions: defined by a parameter, a conditional predicate,  
and parameter value.  
Animation Parameters  
Animation Parameters are variables that are defined within an  
Animator Controller that can be accessed and assigned values  
from scripts.  
This is how a script can control or affect the flow of the state machine.  
Animation Scripting  
Parameters can have their values assigned from a script using  
functions in the Animator class: SetFloat, SetInteger, SetBool,  
SetTrigger and ResetTrigger.  
public class PlayerMovement : MonoBehaviour{  
private Animator animator;  
private void Start(){  
animator = GetComponent<Animator>();  
void FixedUpdate(){  
float horizontalInput = Input.GetAxis("Horizontal");  
if (horizontalInput != 0){  
animator.SetFloat("Speed", Mathf.Abs(rigidBody.velocity.x));  
animator.SetFloat("Speed", -1);  
Animation State Machines  
Animation state machine for the zombie character (idle and  
Exercise 1  
) Continue the implementation of the example by adding the  
jump animation.  
Create the jump state in the animation state machine.  
Create the necessary transitions and parameters.  
Modify the script of the player movement to play the animation.  
The jump animation should not be played in a loop (loop time parameter in the  
animation clip).  
Sprite Editor Automatic Slicing  
Sometimes, a single image contains several related sprites.  
Unity makes it easy to extract elements from a composite image with  
the Sprite Editor.  
Sprite Editor Grid Slicing  
Sometimes, a single image contains several related sprites.  
Unity makes it easy to extract elements from a composite image with  
the Sprite Editor.  
Sprite Editor 9-Slicing  
9-slicing is a 2D technique that allows the reuse of an image at  
various sizes without needing to prepare multiple Assets.  
It involves splitting the image into nine portions, so that when the  
Sprite is resized, the Sprite maintains the same proportion.  
This is useful when creating patterns, such as walls or floors in a 2D  
The four corners (A, C, G and I) do not change in size.  
The B and H sections stretch or tile horizontally.  
The D and F sections stretch or tile vertically.  
The E section stretches or tiles both horizontally and  
Sprite Editor 9-Slicing  
Exercise 2  
) Use the Pixel Adventure pack to create a small level and an  
animated character controlled by the player.  
Pixel Adventure Pack:  
The player character must have the following animations: idle, run, jump,  
and fall (use the Virtual Guy sprites).  
Use the 9-slicing technique with the tileset included in the pack to create  
the level (hint: each sprite to be sliced must be saved as an individual file).  
Further Reading  
Unity User Manual, Available at:  
Sprite Renderer  
Sprite Creator  
Sprite Editor  
9-slicing Sprites  
Sprite Masks  
Sprite Atlas  
Jeremy G. (2017). Introduction to Game Design, Prototyping, and  
Development: from the Concept to Playable Game - with Unity and C# (2nd  
ed.). Boston, MA: Addison-Wesley Professional. ISBN: 978-0134659862  
Hocking, J. (2018). Unity in Action: Multiplatform Game Development in C#  
(2nd ed.). Shelter Island, NY: Manning Publications. ISBN: 978-1617294969