--- title: "Creating and Firing Shells" content_type: tutorial url: "https://learn.unity.com/course/intermediate-3d-game-development/unit/tanks-tutorial/tutorial/creating-and-firing-shells?language=en" language: en container_type: course container_title: "Intermediate 3D Game Development" container_url: "https://learn.unity.com/course/intermediate-3d-game-development.md?language=en" unit_title: "Tanks " unit_url: "https://learn.unity.com/course/intermediate-3d-game-development/unit/tanks-tutorial?language=en" standalone_markdown_url: "https://learn.unity.com/tutorial/creating-and-firing-shells.md?language=en" previous_title: "Tank Health" previous_url: "https://learn.unity.com/course/intermediate-3d-game-development/unit/tanks-tutorial/tutorial/tank-health?language=en" previous_markdown_url: "https://learn.unity.com/course/intermediate-3d-game-development/unit/tanks-tutorial/tutorial/tank-health.md?language=en" next_title: "Game Managers" next_url: "https://learn.unity.com/course/intermediate-3d-game-development/unit/tanks-tutorial/tutorial/game-managers?language=en" next_markdown_url: "https://learn.unity.com/course/intermediate-3d-game-development/unit/tanks-tutorial/tutorial/game-managers.md?language=en" difficulty: intermediate duration_minutes: 65 unity_version: - "5.x" supported_unity_versions: - name: "5.x" url: "https://learn.unity.com/tutorial/creating-and-firing-shells.md?language=en&version=5.x" last_updated: "2026-08-04T14:23:55.000Z" --- # Creating and Firing Shells Learn to create shell projectiles in the Unity Tanks project and implement firing logic with explosion effects. This section of the [Unity Tanks project](https://learn.unity.com/project/tanks-tutorial) demonstrates how to create the shell projectiles and implement the firing of shells along with their explosion effects. ## Materials - [Tanks! Tutorial](https://assetstore.unity.com/packages/essentials/tutorial-projects/tanks-tutorial-46209) ## 1. Shell Creation Phase 5 teaches you how to create a Shell for the tank, creating a radius for explosion. [Video](http://www.youtube.com/watch?v=rkQmXcQRpTw) ## **ShellExplosion Script** ```csharp using UnityEngine; public class ShellExplosion : MonoBehaviour { public LayerMask m_TankMask; // Used to filter what the explosion affects, this should be set to "Players". public ParticleSystem m_ExplosionParticles; // Reference to the particles that will play on explosion. public AudioSource m_ExplosionAudio; // Reference to the audio that will play on explosion. public float m_MaxDamage = 100f; // The amount of damage done if the explosion is centred on a tank. public float m_ExplosionForce = 1000f; // The amount of force added to a tank at the centre of the explosion. public float m_MaxLifeTime = 2f; // The time in seconds before the shell is removed. public float m_ExplosionRadius = 5f; // The maximum distance away from the explosion tanks can be and are still affected. private void Start () { // If it isn't destroyed by then, destroy the shell after it's lifetime. Destroy (gameObject, m_MaxLifeTime); } private void OnTriggerEnter (Collider other) { // Collect all the colliders in a sphere from the shell's current position to a radius of the explosion radius. Collider[] colliders = Physics.OverlapSphere (transform.position, m_ExplosionRadius, m_TankMask); // Go through all the colliders... for (int i = 0; i < colliders.Length; i++) { // ... and find their rigidbody. Rigidbody targetRigidbody = colliders[i].GetComponent (); // If they don't have a rigidbody, go on to the next collider. if (!targetRigidbody) continue; // Add an explosion force. targetRigidbody.AddExplosionForce (m_ExplosionForce, transform.position, m_ExplosionRadius); // Find the TankHealth script associated with the rigidbody. TankHealth targetHealth = targetRigidbody.GetComponent (); // If there is no TankHealth script attached to the gameobject, go on to the next collider. if (!targetHealth) continue; // Calculate the amount of damage the target should take based on it's distance from the shell. float damage = CalculateDamage (targetRigidbody.position); // Deal this damage to the tank. targetHealth.TakeDamage (damage); } // Unparent the particles from the shell. m_ExplosionParticles.transform.parent = null; // Play the particle system. m_ExplosionParticles.Play(); // Play the explosion sound effect. m_ExplosionAudio.Play(); // Once the particles have finished, destroy the gameobject they are on. Destroy (m_ExplosionParticles.gameObject, m_ExplosionParticles.duration); // Destroy the shell. Destroy (gameObject); } private float CalculateDamage (Vector3 targetPosition) { // Create a vector from the shell to the target. Vector3 explosionToTarget = targetPosition - transform.position; // Calculate the distance from the shell to the target. float explosionDistance = explosionToTarget.magnitude; // Calculate the proportion of the maximum distance (the explosionRadius) the target is away. float relativeDistance = (m_ExplosionRadius - explosionDistance) / m_ExplosionRadius; // Calculate damage as this proportion of the maximum possible damage. float damage = relativeDistance * m_MaxDamage; // Make sure that the minimum damage is always 0. damage = Mathf.Max (0f, damage); return damage; } } ``` ## 2. Firing Shells Phase 6 teaches you how to fire projectiles, and make a UI & Sound fx to accompany the mechanic. [Video](http://www.youtube.com/watch?v=_In3KT97aTw) ## **TankShooting Script** ```csharp using UnityEngine; using UnityEngine.UI; public class TankShooting : MonoBehaviour { public int m_PlayerNumber = 1; // Used to identify the different players. public Rigidbody m_Shell; // Prefab of the shell. public Transform m_FireTransform; // A child of the tank where the shells are spawned. public Slider m_AimSlider; // A child of the tank that displays the current launch force. public AudioSource m_ShootingAudio; // Reference to the audio source used to play the shooting audio. NB: different to the movement audio source. public AudioClip m_ChargingClip; // Audio that plays when each shot is charging up. public AudioClip m_FireClip; // Audio that plays when each shot is fired. public float m_MinLaunchForce = 15f; // The force given to the shell if the fire button is not held. public float m_MaxLaunchForce = 30f; // The force given to the shell if the fire button is held for the max charge time. public float m_MaxChargeTime = 0.75f; // How long the shell can charge for before it is fired at max force. private string m_FireButton; // The input axis that is used for launching shells. private float m_CurrentLaunchForce; // The force that will be given to the shell when the fire button is released. private float m_ChargeSpeed; // How fast the launch force increases, based on the max charge time. private bool m_Fired; // Whether or not the shell has been launched with this button press. private void OnEnable() { // When the tank is turned on, reset the launch force and the UI m_CurrentLaunchForce = m_MinLaunchForce; m_AimSlider.value = m_MinLaunchForce; } private void Start () { // The fire axis is based on the player number. m_FireButton = "Fire" + m_PlayerNumber; // The rate that the launch force charges up is the range of possible forces by the max charge time. m_ChargeSpeed = (m_MaxLaunchForce - m_MinLaunchForce) / m_MaxChargeTime; } private void Update () { // The slider should have a default value of the minimum launch force. m_AimSlider.value = m_MinLaunchForce; // If the max force has been exceeded and the shell hasn't yet been launched... if (m_CurrentLaunchForce >= m_MaxLaunchForce && !m_Fired) { // ... use the max force and launch the shell. m_CurrentLaunchForce = m_MaxLaunchForce; Fire (); } // Otherwise, if the fire button has just started being pressed... else if (Input.GetButtonDown (m_FireButton)) { // ... reset the fired flag and reset the launch force. m_Fired = false; m_CurrentLaunchForce = m_MinLaunchForce; // Change the clip to the charging clip and start it playing. m_ShootingAudio.clip = m_ChargingClip; m_ShootingAudio.Play (); } // Otherwise, if the fire button is being held and the shell hasn't been launched yet... else if (Input.GetButton (m_FireButton) && !m_Fired) { // Increment the launch force and update the slider. m_CurrentLaunchForce += m_ChargeSpeed * Time.deltaTime; m_AimSlider.value = m_CurrentLaunchForce; } // Otherwise, if the fire button is released and the shell hasn't been launched yet... else if (Input.GetButtonUp (m_FireButton) && !m_Fired) { // ... launch the shell. Fire (); } } private void Fire () { // Set the fired flag so only Fire is only called once. m_Fired = true; // Create an instance of the shell and store a reference to it's rigidbody. Rigidbody shellInstance = Instantiate (m_Shell, m_FireTransform.position, m_FireTransform.rotation) as Rigidbody; // Set the shell's velocity to the launch force in the fire position's forward direction. shellInstance.velocity = m_CurrentLaunchForce * m_FireTransform.forward; ; // Change the clip to the firing clip and play it. m_ShootingAudio.clip = m_FireClip; m_ShootingAudio.Play (); // Reset the launch force. This is a precaution in case of missing button events. m_CurrentLaunchForce = m_MinLaunchForce; } } ```