ashokslsk / UnityBallShooter

Comprehensive unity guide for creating a physics based ball shooter.

Unity

Writing 3D game.

Scene is a collection of object, Which we can use to express the game or unity application.

Right click in the Assets -> And create a new scene called Main.

Add cube and using the unity shortcuts Q,W,E,R,T stretch and align the cube as Gym floor.

RigidBody Physics

Add a component to your game object called rigidbody

Smart copies with prefabs

Prefabs are like templates, Using prefabs we can customise the 3d object look and feel.

Angular Drag

Just adds the angular drag on the natural physics motion. Basketball will slow down when this is applied.

Instantiate Method.

Spawn a ball on spacebar

use getKeydown() method

if statement inside Update() method

Instantiate() inside the if condition

Adding Velocity to the ball

Directional velocity can be added as shown below.

void Update () {
		if (Input.GetKeyDown (KeyCode.LeftArrow)) {
			GameObject instance = Instantiate (ballPrefab);
			Rigidbody rb = instance.GetComponent<Rigidbody>();
			rb.velocity = Vector3.left;
		}
	
		if (Input.GetKeyDown (KeyCode.RightArrow)) {
			GameObject instance = Instantiate (ballPrefab);
			Rigidbody rb = instance.GetComponent<Rigidbody>();
			rb.velocity = Vector3.right;
		}

		if (Input.GetKeyDown (KeyCode.UpArrow)) {
			GameObject instance = Instantiate (ballPrefab);
			Rigidbody rb = instance.GetComponent<Rigidbody>();
			rb.velocity = Vector3.up;
		}

		if (Input.GetKeyDown (KeyCode.DownArrow)) {
			GameObject instance = Instantiate (ballPrefab);
			Rigidbody rb = instance.GetComponent<Rigidbody>();
			rb.velocity = Vector3.down;
		}

	}

Rotating the camera in the code

We will rotate the camera based on the concept called Quaternion.

// Update is called once per frame
	void Update () {
		transform.rotation = Quaternion.Euler (0, 1, 0) * transform.rotation;

	}

Taking mouse input

Go to edit inside project settings add the Input component

then in the component script.

	// Update is called once per frame
	void Update () {
		float rotationSpeed = 5.0f;
		float mouseX = Input.GetAxis ("Mouse X") * rotationSpeed;
		float mouseY = Input.GetAxis ("Mouse Y") * rotationSpeed;
		transform.rotation = Quaternion.Euler (-mouseY, mouseX, 0) * transform.rotation;

	}

Creating a camera gimbal

Using localRotation object we can eliminate the tilting

// Update is called once per frame
	void Update () {
		float rotationSpeed = 5.0f;
		float mouseX = Input.GetAxis ("Mouse X") * rotationSpeed;
		float mouseY = Input.GetAxis ("Mouse Y") * rotationSpeed;
		transform.localRotation = Quaternion.Euler (0, mouseX, 0) * transform.localRotation;
		Camera camera = GetComponentInChildren<Camera> ();
		camera.transform.localRotation = Quaternion.Euler (-mouseY, 0, 0) * camera.transform.localRotation;
	}

Setting the ball location and firing

	if (Input.GetButtonDown ("Fire1")) {
			GameObject instance = Instantiate (ballPrefab);
			instance.transform.position = transform.position;
			Rigidbody rb = instance.GetComponent<Rigidbody>();
			rb.velocity = Vector3.forward * Speed;
		}