// in ofApp.h
float angle;
float cameraDistance;
ofCamera camera;

// in setup
angle = 0;
cameraDistance = 100;

// function
void ofApp::updateCamera() {
	camera.setPosition(cameraDistance * sin(angle), cameraDistance * sin(angle), 100);
	camera.lookAt(ofVec3f(0, 0, 0));
	angle += 0.01;
}