INDIANAPOLIS — The Lakers-New Jersey Nets-Houston Rockets trade became official today. The Lakers sent guard Sasha Vujacic and a protected first-round draft pick in 2011 to the Nets for forward Joe Smith, a second-round pick in ’11 and a second-round pick in ’12. The Lakers also received the draft rights to Sergei Lishouk from the Rockets. The picks originally belonged to Golden State (2011) and Chicago (2012). The Nets also received a protected 2012 pick from the Rockets. Houston got guard Terrence Williams from New Jersey. The teams agreed in principle Tuesday, but couldn’t formally announce it until today, the first day last summer’s free-agent signees, including Smith, could be dealt. Smith is scheduled to undergo a physical Wednesday and join the team for its practice later in the day in Philadelphia. If all goes well, he could be activated for Friday’s game against the 76ers.