private boolean isDropPlaneIntersected(char direction, int index) {
		if (index < 0 || index >= modelManager.frame.atomCount)
			return false;
		Atom at = modelManager.frame.atoms[index];
		Point3f center = dropPlane.getCenter();
		float radius = at.getVanderwaalsRadiusFloat();
		switch (direction) {
		case 'x':
			if (Math.abs(at.getAtomX() - center.x) < radius)
				return true;
			break;
		case 'y':
			if (Math.abs(at.getAtomY() - center.y) < radius)
				return true;
			break;
		case 'z':
			if (Math.abs(at.getAtomZ() - center.z) < radius)
				return true;
			break;
		}
		return false;
	}