private void updatePressureQ() {
		if (obstacles == null || obstacles.isEmpty())
			return;
		int c = movie.getCapacity();
		RectangularObstacle obs = null;
		synchronized (obstacles.getSynchronizationLock()) {
			for (int i = 0, n = obstacles.size(); i < n; i++) {
				obs = obstacles.get(i);
				try {
					obs.updatePQ();
				} catch (Exception e) {
					obs.initializePEQ(c);
					obs.initializePWQ(c);
					obs.initializePSQ(c);
					obs.initializePNQ(c);
					obs.updatePQ();
				}
			}
		}
	}