Point filtering - texture pixels become blocky up close.

	renderer.material.mainTexture.filterMode = FilterMode.Point;

using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    void Example() {
        renderer.material.mainTexture.filterMode = FilterMode.Point;
    }
}

import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	def Example() as void:
		renderer.material.mainTexture.filterMode = FilterMode.Point