Rasheed Wallace is living in coach Mike Woodson's penthouse, and Marcus Camby appears to be in the doghouse. As Wallace's role grows, Camby, one of the Knicks' big free-agent signings, has faded from view — sitting out the past two games in San Antonio and Memphis. Even with Wallace and Chandler getting five fouls in the third quarter against the big, beefy Grizzlies, undersized Kurt Thomas was chosen to fill in as Camby sat. Camby missed all of preseason and the first two regular-season games resting his calf strain. Asked after the Memphis game if he was OK physically, Camby emphatically said, "I feel great.'' The yin and yang of the volatile Wallace was displayed in Friday's combative battle in Memphis, when the Knicks received the first blemish to their perfect record — no longer the league's lone unbeaten team. But as much as Wallace pushes the envelope, he is squarely Woodson's guy. Still brandishing a mighty 6-1 clip, the Knicks host the disappointing Pacers in a noon Garden matinee today. Then they hit the road again for a three-game trip through New Orleans, Dallas and Houston, for their first showdown with Jeremy Lin.