Objects: Creation, Deletion and Time

• Main Camera: Orthographic, Size 100. The world spans y = −100 to +100.
• The hero, eggs and enemies must each be a sprite made from an image (Texture Type: Sprite (2D and UI)). Built-in shapes and 3D objects don't count.
• Sizes below are Transform Scale values, as in EX1. How big an object looks in world units also depends on its image's pixel size and Pixels Per Unit: my solution uses 128, so the 180-pixel hero at scale 5 is about 7 units wide.

Use any images you like, or the ones in my solution:

GreenUp.PNGHero Egg.pngEgg Plane.pngEnemy

Transform Scale (5, 5, 1).

• Transform Scale (1, 1, 1), created from a prefab at the hero's position.
• Aligned with the hero's transform.up at the moment it's fired, and then travels along its own transform.up at 40 units/second.
• An egg is destroyed when it either leaves the world bounds or hits an enemy.

• Transform Scale (5, 5, 1), created from a prefab. They don't move in this exercise.
• There are always exactly 10 enemies, each placed at a random position within the central 90% of the world bounds.
• As soon as an enemy is destroyed, spawn a new one under the same rules.

SpriteRenderer r = GetComponent<SpriteRenderer>();
Color c = r.color;
c.a *= 0.8f;
r.color = c;

Show the application status on screen with a UI Text (TextMeshPro) object, updated every frame. It must include:

• Hero: control mode (Mouse/Keyboard), and the number of enemies the hero has touched
• Egg: the number of eggs currently in the world
• Enemy: the current enemy count (always 10), and the total number destroyed

For example:

HERO: Drive(Mouse)  TouchedEnemy(3)
EGG: OnScreen(12)
ENEMY: Count(10)  Destroyed(7)

Q quits the application. As in EX1, this only works in the built EXE.

using UnityEngine.InputSystem;

Vector3 p = Camera.main.ScreenToWorldPoint(Mouse.current.position.ReadValue());
p.z = 0f;
transform.localPosition = p;

Use Keyboard.current.wKey.isPressed for held keys and Keyboard.current.mKey.wasPressedThisFrame for toggles. Don't use Input.GetAxis(); it throws an exception in Unity 6 projects.

float dt = Time.smoothDeltaTime;
mSpeed += kAcceleration * dt;                        // W held: 10 units/second²
transform.Rotate(0f, 0f, kTurnRate * dt);           // A held: 45 degrees/second
transform.localPosition += mSpeed * dt * transform.up;

Remember the time of the last shot (Time.time) and only fire again once 0.2 seconds have passed. Create the egg with Instantiate(eggPrefab, transform.position, transform.rotation) so it starts with the hero's orientation.

Follow Module 2.6. For OnTriggerEnter2D to be called, give the hero and egg a Rigidbody2D (Body Type Kinematic) and a BoxCollider2D with Is Trigger checked, and give the enemy a BoxCollider2D with Is Trigger checked.

The world is Camera.main.orthographicSize high on each side of the camera, and orthographicSize * Camera.main.aspect wide on each side.

A single Game Manager object (see Module 2.3) is a good place to keep the counts and spawn enemies. Eggs can report their creation and destruction to it from Start() and OnDestroy().

• Keep the hero inside the world bounds in keyboard mode.
• Show the hero's current speed in the status text.

1. A zip file named YourNameEX2.zip containing your entire project: every file in Assets, Packages and ProjectSettings, and nothing more.
2. A separate folder with your PC EXE build. We'll double-click the EXE to run your project.

Self-check before you submit

• I unzipped my zip into a new, empty folder and opened it in Unity 6000.3.11f1. It opens and runs.
• The zip has only Assets, Packages and ProjectSettings.
• Double-clicking the EXE runs the game, and Q quits it.
• The hero, eggs and enemies are sprites made from images.
• Holding Space fires about 5 eggs per second.
• The egg count in the status text goes back to 0 once all eggs have left the world or hit enemies.
• Enemy count always shows 10; an enemy fades on each egg hit and disappears on the 4th.
• In keyboard mode, holding S stops the hero (speed 0) rather than reversing it.
• My hero script has the 2–3 sentence explanation comment at the top.