Test

Assets/Standard Assets/Utility/DragRigidbody.cs

@@ -0,0 +1,96 @@
+using System;
+using System.Collections;
+using UnityEngine;
+
+namespace UnityStandardAssets.Utility
+{
+    public class DragRigidbody : MonoBehaviour
+    {
+        const float k_Spring = 50.0f;
+        const float k_Damper = 5.0f;
+        const float k_Drag = 10.0f;
+        const float k_AngularDrag = 5.0f;
+        const float k_Distance = 0.2f;
+        const bool k_AttachToCenterOfMass = false;
+
+        private SpringJoint m_SpringJoint;
+
+
+        private void Update()
+        {
+            // Make sure the user pressed the mouse down
+            if (!Input.GetMouseButtonDown(0))
+            {
+                return;
+            }
+
+            var mainCamera = FindCamera();
+
+            // We need to actually hit an object
+            RaycastHit hit = new RaycastHit();
+            if (
+                !Physics.Raycast(mainCamera.ScreenPointToRay(Input.mousePosition).origin,
+                                 mainCamera.ScreenPointToRay(Input.mousePosition).direction, out hit, 100,
+                                 Physics.DefaultRaycastLayers))
+            {
+                return;
+            }
+            // We need to hit a rigidbody that is not kinematic
+            if (!hit.rigidbody || hit.rigidbody.isKinematic)
+            {
+                return;
+            }
+
+            if (!m_SpringJoint)
+            {
+                var go = new GameObject("Rigidbody dragger");
+                Rigidbody body = go.AddComponent<Rigidbody>();
+                m_SpringJoint = go.AddComponent<SpringJoint>();
+                body.isKinematic = true;
+            }
+
+            m_SpringJoint.transform.position = hit.point;
+            m_SpringJoint.anchor = Vector3.zero;
+
+            m_SpringJoint.spring = k_Spring;
+            m_SpringJoint.damper = k_Damper;
+            m_SpringJoint.maxDistance = k_Distance;
+            m_SpringJoint.connectedBody = hit.rigidbody;
+
+            StartCoroutine("DragObject", hit.distance);
+        }
+
+
+        private IEnumerator DragObject(float distance)
+        {
+            var oldDrag = m_SpringJoint.connectedBody.drag;
+            var oldAngularDrag = m_SpringJoint.connectedBody.angularDrag;
+            m_SpringJoint.connectedBody.drag = k_Drag;
+            m_SpringJoint.connectedBody.angularDrag = k_AngularDrag;
+            var mainCamera = FindCamera();
+            while (Input.GetMouseButton(0))
+            {
+                var ray = mainCamera.ScreenPointToRay(Input.mousePosition);
+                m_SpringJoint.transform.position = ray.GetPoint(distance);
+                yield return null;
+            }
+            if (m_SpringJoint.connectedBody)
+            {
+                m_SpringJoint.connectedBody.drag = oldDrag;
+                m_SpringJoint.connectedBody.angularDrag = oldAngularDrag;
+                m_SpringJoint.connectedBody = null;
+            }
+        }
+
+
+        private Camera FindCamera()
+        {
+            if (GetComponent<Camera>())
+            {
+                return GetComponent<Camera>();
+            }
+
+            return Camera.main;
+        }
+    }
+}