matching camera to rectangle

Hey all,

In the attached screenshot I am trying to get the screen’s view to
match the yellow rectangle that is tracking the user.

The yellow rectangle is generated per user (center being the center of the user) and moves as the user moves. I would like the camera to move left/right/up/down with the rectangle

this generates the rectangle
viewPort = ofRectangle(center.x-ofGetWidth()/2,
center.y-ofGetHeight()/2, ofGetWidth(), ofGetHeight());

I thought passing in the rect via camera.begin(viewPort) would do it but looking at the viewport example it appears it just crops it.

any clues would be appreciated!