In-Class Exercise 2:  Control, Prefab, Working with the Camera component on the MainCamera, collision, and UI

You can start this exercise based on Module 2 Example-6

Step 1 (15 minutes): Working with Prefab

• Review of GameObject creation:
• Create a Plane object of size 1.6x1.9 using this texture
• Review of Script
• Create a MoveForward script to:
• At initialization:
• Rotate (in Z) by a random degree between -180 and +180 degrees
• Compute a random speed of between 0.5 and 1 units/sec
• Each Update: Move the Plane forward at the computed speed
• Practice Prefab
• Define a Prefab based on the forward moving Plane
• Create four instances of the Plane and run to see them flying randomly around
• Learn:
• Work with the Random function
• Rotation set by: Quaternion.AngleAxis()
• You can change transform.up to rotate objects

Step 2 (10 minutes): Work with the Camera component on the MainCamera

• Update the MoveForward script to remove a forward moving plane when its center is outside the camera bound
• Challenge: this is slightly challenging, if you cannot figure this out, look at my solution (link to my project is at the end of this document, you can look at my MoveForward.cs script)
• Hint: You know the camera position and the height of the world!!
• Camera.main: MainCamera’s Camera componment
• Camera.gameObject.transform.localPosition: location of the camera
• Camera.orthographicsSize: camera half-height
• Camera.orthographicsSize * Camera.aspect: camera half-width
• Now, run to see planes flying and disappear when are outside of the camera bound
• Learn:
• Work with the Camera component
• Trust the arithmetic you know and apply

Step 3 (15 minutes): Support Collision

• Define collision
• Create a GreenUp sprite object using this texture (1.5x1.8)
• GreenUp: add a Collider (isTrigger set to true) and RigidBody2D
• Plane Prefab: add a Collider
• Hint: you are probably modifying an instance of Plane, you will have to re-create the Prefab, or, modify the Prefab directly
• In GreenUP, define onTriggerEnter2D() to destroy the object that is has collided with
• Learn:
• Note the difference between editing an instance and the Prefab

Step 4 (may be many minutes): Button

• Define a Button (Button Text Mesh Pro) that always appear at the top-left of the game window (even after game window size change):
• The button should show “Create One”
• Hint: You will have to “Import TMP”
• No need to import TMP Examples and Extras
• Label for the button is in a child object of the Button (click on the Triangle besides the Button)
• When pressed on this button, create a new Plane Prefab at (0, 0)

For reference: this is what my project looks like at the end of the above exercise.

More Steps (on your own)

• Add in support for the Egg Prefab to be an active colliding object
• Hint: add Collider and RigidShape components, and remember to check isTrigger on the Collider.
• In the EggBehavior script: remove the colliding object
• Now, try running … your Egg will
• Notice space bar now will destroy the GreenUp!
• Hint: GreenUp is the first object an Egg will collide with!
• Now, disable GreenUp collision (remove the Collider and the RigidShape)
• Hint: alternate solution, in Egg::OnCollisionEnter, check the name of the colliding object and do not destroy if the name is “GreenUp”. If GreenUp can collide, you can continue to eliminate Plane with GreenUp.
• Now, try running, … your Egg will destroy a plane, … AND … continue to travel!
• How to fix this?
• Hint: the Egg should destroy self upon collision
• Now, Integrate GreenUp rotation controls from Module 2 Example 1
• Run to make sure you can now navigate the GreenUp
• Support rotating the Eggs when spawning them from the GreenUp
• Now: you can hit and remove the planes with the Eggs spawned from the GreenUp!