GenerateTextObjectAndPositionDuringRuntime Allows for positioning labels over the world objects, use with LOD to decide draw distances.

GenerateTextObjectAndPositionDuringRuntime.cs

using UnityEngine;
using System.Collections;
using UnityEngine.UI;

public class GenerateTextObjectAndPositionDuringRuntime : MonoBehaviour
{

    public Canvas CanvasToPopulate;
    public GameObject TextPrefab;
    private GameObject instantiatedPrefab;
    private Text textObject;
    private RectTransform rectReference;

    public int FontSize;

    public float LabelVerticalOffset = 0f;

    public string textToDisplay;

    bool draw = false;


    void Start()
    {
        instantiatedPrefab = Instantiate(TextPrefab);
        textObject = instantiatedPrefab.GetComponent<Text>();
        rectReference = CanvasToPopulate.GetComponent<RectTransform>();
        instantiatedPrefab.transform.SetParent(CanvasToPopulate.transform, false);
        textObject.text = textToDisplay;

        if (FontSize > 0)
        {
            textObject.fontSize = FontSize;
        }

        textObject.enabled = false;
        draw = false;
    }

    void OnBecameInvisible()
    {
     
        textObject.enabled = false;
        draw = false;
       
    }
    void OnBecameVisible()
    {  
        draw = true;

    }

    // Keep it centralised.
    void Update()
    {
        MoveObject();
    }

    private void MoveObject()
    {

        if (!draw)
            return;
       
            Vector2 pos = WorldToCanvasPosition.ConvertWorldToCanvasPosition(rectReference, Camera.main, transform.position);
            textObject.rectTransform.position = new Vector3(pos.x, pos.y + LabelVerticalOffset);
            textObject.enabled = true;

    }
}