Drag and Drop with wall avoidance

Drag and Drop with wall avoidance Unity

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class DragAndDropBoundaries : MonoBehaviour {

	bool active = false;
	public Color selectedColour;
	public Color idleColour;
	public float velocityMulitplier = 2f;

	Color newColour = Color.white;
	void SetColour (Color c) {
		newColour = c;
		//GetComponent<Renderer> ().material.color = c;
	}

	void OnMouseDown () {
		active = true;
		transform.eulerAngles = Vector3.zero;
		SetColour (selectedColour);

	}

	void OnMouseUp () {
		active = false;
		SetColour (idleColour);
	}

	void ColourTransition () {
		GetComponent<Renderer> ().material.color = Color.Lerp (GetComponent<Renderer> ().material.color, newColour, 2 * Time.deltaTime);
	}

	void FixedUpdate () {

		ColourTransition ();

		if (active) {
			var v3 = new Vector3 (Input.mousePosition.x, Input.mousePosition.y, 10f);
			v3 = Camera.main.ScreenToWorldPoint (v3);
			GetComponent<Rigidbody> ().velocity = (v3 - transform.position) * velocityMulitplier;
		}
	}
}