Initial commit

Assets/Scripts/ItemPickup.cs

@@ -0,0 +1,138 @@
+using UnityEngine;
+using UnityEngine.InputSystem;
+
+public class ItemPickup : MonoBehaviour
+{
+    [Header("Layer Settings")]
+    public LayerMask pickupLayer;
+    [Header("Input Settings")]
+    public InputActionAsset inputActionAsset;
+
+    [Header("Pickup Settings")]
+    public float pickupSpeed = 10f; // How fast it snaps to your hand
+    public float holdDistance = 3f;  // Default distance
+
+    private InputAction pickUpAction;
+    private Camera mainCamera;
+    
+    // We store the Rigidbody instead of the GameObject
+    private Rigidbody currentPickedRB = null; 
+
+    void Awake()
+    {
+        mainCamera = Camera.main;
+    }
+
+    private void OnEnable()
+    {
+        if (inputActionAsset != null)
+        {
+            pickUpAction = inputActionAsset.FindAction("PickUp");
+            if (pickUpAction != null)
+            {
+                pickUpAction.Enable();
+                pickUpAction.started += OnPickUpStarted;
+                pickUpAction.canceled += OnPickUpCanceled;
+            }
+        }
+    }
+
+    private void OnDisable()
+    {
+        if (pickUpAction != null)
+        {
+            pickUpAction.started -= OnPickUpStarted;
+            pickUpAction.canceled -= OnPickUpCanceled;
+            pickUpAction.Disable();
+        }
+    }
+
+    private void OnPickUpStarted(InputAction.CallbackContext context)
+    {
+        // 1. Raycast to find object
+        Vector2 mousePos = Mouse.current.position.ReadValue();
+        Ray ray = mainCamera.ScreenPointToRay(mousePos);
+        RaycastHit hit;
+
+        if (Physics.Raycast(ray, out hit))
+        {
+            // Check if it has a Rigidbody and match layer
+            if (hit.collider.TryGetComponent(out Rigidbody rb) && 
+                ((1 << hit.collider.gameObject.layer) & pickupLayer) != 0)
+            {
+                currentPickedRB = rb;
+                
+                // --- CRITICAL FIX START ---
+                // If we pick it off a Shelf, it is frozen (Kinematic). 
+                // We must unfreeze it immediately so we can apply velocity.
+                currentPickedRB.isKinematic = false; 
+                // --- CRITICAL FIX END ---
+
+                // 2. Setup Physics for "Holding"
+                currentPickedRB.useGravity = false; 
+                
+                // Add damping so it doesn't drift around like it's on ice
+                currentPickedRB.linearDamping = 10; 
+                currentPickedRB.angularDamping = 5;
+
+                // Optional: Calculate distance to keep it where we clicked
+                holdDistance = hit.distance;
+
+                // Notify RayCastSystem
+                RayCastSystem rayCastSystem = GetComponent<RayCastSystem>();
+                if (rayCastSystem != null)
+                {
+                    rayCastSystem.SetCurrentPickedRB(rb);
+                }
+            }
+        }
+    }
+
+    private void OnPickUpCanceled(InputAction.CallbackContext context)
+    {
+        if (currentPickedRB != null)
+        {
+            // 3. Reset Physics properties
+            currentPickedRB.useGravity = true;
+            currentPickedRB.linearDamping = 0; // Reset to default (usually 0)
+            currentPickedRB.angularDamping = 0.05f;
+
+            currentPickedRB = null;
+            // Notify RayCastSystem that an object is no longer picked up
+            RayCastSystem rayCastSystem = GetComponent<RayCastSystem>();
+            if (rayCastSystem != null)
+            {
+                rayCastSystem.SetCurrentPickedRB(null);
+            }
+        }
+    }
+
+    // Physics movement must be in FixedUpdate
+    private void FixedUpdate()
+    {
+        if (currentPickedRB != null)
+        {
+            MoveObjectPhysics();
+        }
+    }
+
+    private void MoveObjectPhysics()
+    {
+        Vector2 mousePos = Mouse.current.position.ReadValue();
+        Ray ray = mainCamera.ScreenPointToRay(mousePos);
+
+        // Where we want the object to be
+        Vector3 targetPosition = ray.GetPoint(holdDistance);
+
+        // Calculate direction vector: Target - Current
+        Vector3 direction = targetPosition - currentPickedRB.position;
+
+        // Apply Velocity
+        // We multiply by pickupSpeed to make it responsive
+        // The physics engine handles the rest (Mass 1 vs Mass 100 collisions)
+        currentPickedRB.linearVelocity = direction * pickupSpeed;
+
+        // Note: In Unity versions older than 2023.3, use 'velocity' instead of 'linearVelocity'
+        // currentPickedRB.velocity = direction * pickupSpeed;
+    }
+}