PickUpObject.cs

using UnityEngine;
using System.Collections;

public class PickUpObject : MonoBehaviour {

    private Rigidbody obj;
    public enum CatchState {Empty, Holding, Dropping}
    public CatchState catchState = 0;
    public float throwStrength = 8.0f;
    public float straightenSpeed = 10.0f;

    public float reachDist = 4.0f;
    public LayerMask layerMask = -1;

    public void DropObject() {
        catchState = CatchState.Dropping;
        print("Dropping");
    }

    // Update handles the inputs
    void Update () {
        if(catchState == CatchState.Empty) {
            if(Input.GetButtonDown("Fire2")) {
                RaycastHit hit;
                if(Physics.Raycast(transform.position, transform.forward, out hit, reachDist, layerMask)) {
                    PickUp(hit.transform.gameObject);
                    catchState = CatchState.Holding;
                }
            }
        }

        else if(catchState == CatchState.Holding) {

            if(Input.GetButton("Drop")) {
                StartCoroutine(Straighten());
            }

            else StopCoroutine("Straighten");

            if(Input.GetButtonDown("Fire2")) {
                catchState = CatchState.Dropping;
            }
        }

        if(obj == null) catchState = CatchState.Empty;

    }

    void FixedUpdate () {

        if(catchState == CatchState.Holding) {
            obj.MovePosition(transform.position + transform.forward * 2f);
        }

        else if(catchState == CatchState.Dropping) {
            Drop();
            catchState = CatchState.Empty;
        }
    }

    void Drop () {

        StopCoroutine("Straighten");
/*
        Color c = obj.gameObject.renderer.material.color;
        c.a = 1.0f;
        obj.gameObject.renderer.material.color = c;
*/
        obj.gameObject.renderer.material.shader = Shader.Find("HardSurface/Hardsurface Free/Opaque Bump");

        // Enable...

        // Single gavity
        try {
            obj.GetComponent<SingleGravity>().enabled = true;
        }
        catch {}

        // No gravity
        try {
            obj.GetComponent<NoGravity>().enabled = true;
        }
        catch {
            // If there is no NoGravity component, enable gravity
            obj.useGravity = true;
        }

        // Anti gravity
        try {
            obj.GetComponent<AntiGravity>().enabled = true;
        }
        catch {}

        // Reset the anglular velocity
        obj.angularVelocity = Vector3.zero;

        // Add force if not holding the drop button
        if(!Input.GetButton("Drop")) {
            obj.velocity = ((transform.forward) * throwStrength) + transform.parent.rigidbody.velocity * 1.5f;
        }

        else {
            obj.velocity = Vector3.zero;
        }

        // Remove the reference to the object
        obj = null;
    }

    void PickUp (GameObject Object) {

        obj = Object.rigidbody;
        obj.useGravity = false;
/*
        Color c = obj.gameObject.renderer.material.color;
        c.a = 0.6f;
        obj.gameObject.renderer.material.color = c;
*/
        obj.gameObject.renderer.material.shader = Shader.Find("HardSurface/Hardsurface Free/Transparent Bump");

        try {
            obj.GetComponent<SingleGravity>().enabled = false;
        }
        catch {}

        try {
            obj.GetComponent<NoGravity>().enabled = false;
        }
        catch {}

        try {
            obj.GetComponent<AntiGravity>().enabled = false;
        }
        catch {}
    }

    IEnumerator Straighten() {
        Quaternion start = obj.transform.rotation;
        Quaternion end = Quaternion.Euler(Vector3.zero);

        obj.angularVelocity = Vector3.zero;

        float t = 0f;

        while(obj.transform.rotation != end) {

            obj.transform.rotation = Quaternion.Lerp(start, end, t);

            t += straightenSpeed;

            yield return new WaitForEndOfFrame();
        }
    }
}