An approximation of how many pixels the terrain will pop in the worst case when switching lod.

	function Start () {
		Terrain.activeTerrain.heightmapPixelError = 10;
	}

using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    void Start() {
        Terrain.activeTerrain.heightmapPixelError = 10;
    }
}

import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	def Start() as void:
		Terrain.activeTerrain.heightmapPixelError = 10