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Assets/Third Parties/Opsive/UltimateCharacterController/Scripts/Objects/ItemAssist/Shell.cs

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+/// ---------------------------------------------
+/// Ultimate Character Controller
+/// Copyright (c) Opsive. All Rights Reserved.
+/// https://www.opsive.com
+/// ---------------------------------------------
+
+namespace Opsive.UltimateCharacterController.Objects.ItemAssist
+{
+    using Opsive.Shared.Game;
+    using UnityEngine;
+
+    /// <summary>
+    /// Represents a shell casing which uses the trajectory object for kinematic shell movement.
+    /// </summary>
+    [RequireComponent(typeof(Rigidbody))]
+    public class Shell : TrajectoryObject
+    {
+        [Tooltip("Time to live in seconds before the shell is removed.")]
+        [SerializeField] protected float m_Lifespan = 10;
+        [Tooltip("Chance of shell not being removed after settling on the ground.")]
+        [Range(0, 1)] [SerializeField] protected float m_Persistence = 1;
+
+        private float m_RemoveTime;
+        private Vector3 m_StartScale;
+
+        /// <summary>
+        /// Initialize the default values.
+        /// </summary>
+        protected override void Awake()
+        {
+            base.Awake();
+
+            m_StartScale = transform.localScale;
+
+            // The Rigidbody is only used to notify Unity that the object isn't static. The Rigidbody doesn't control any movement.
+            var rigidbody = GetComponent<Rigidbody>();
+            rigidbody.mass = m_Mass;
+            rigidbody.isKinematic = true;
+            rigidbody.constraints = RigidbodyConstraints.FreezeAll;
+        }
+
+        /// <summary>
+        /// The shell has been spawned - reset the timing and component values.
+        /// </summary>
+        protected override void OnEnable()
+        {
+            base.OnEnable();
+
+            m_RemoveTime = Time.time + m_Lifespan;
+            m_Transform.localScale = m_StartScale;
+
+            if (m_Collider != null) {
+                m_Collider.enabled = true;
+            }
+        }
+
+        /// <summary>
+        /// Move and rotate the object according to a parabolic trajectory.
+        /// </summary>
+        protected override void FixedUpdate()
+        {
+            base.FixedUpdate();
+
+            if (Time.time > m_RemoveTime) { // The shell should be removed.
+                m_Transform.localScale = Vector3.Lerp(m_Transform.localScale, Vector3.zero, Utility.TimeUtility.FramerateDeltaTime * 0.2f);
+                if (Time.time > m_RemoveTime + 0.5f) {
+                    ObjectPool.Destroy(m_GameObject);
+                }
+            }
+        }
+
+        /// <summary>
+        /// The object has collided with another object.
+        /// </summary>
+        /// <param name="hit">The RaycastHit of the object. Can be null.</param>
+        protected override void OnCollision(RaycastHit? hit)
+        {
+            base.OnCollision(hit);
+
+            if (m_Velocity.sqrMagnitude > 4) { // Hard bounce.
+                // Apply more random rotation velocity to make the shell behave a bit unpredictably on a hard bounce (similar to real brass shell behavior).
+                AddTorque(Random.rotation.eulerAngles * 0.15f * (Random.value > 0.5f ? 1 : -1));
+            } else if (Random.value > m_Persistence) { // Soft bounce.
+                // Remove the shell after half a second on a soft bounce.
+                m_RemoveTime = Time.time + 0.5f;
+            }
+        }
+    }
+}