“Natura Obscura” is a major departure for Englewood’s Museum of Outdoor Arts, transforming one of the region’s most respected showplaces for static painting, sculpture and other gallery-friendly art objects into something more like a theme park, a family-fun attraction that’s full of lights, sounds, sets and storylines. You don’t just go look at the offerings in “Natura Obscura”: You enter them and activate them, you feel the flowers and ogle the owls, you swing on a swing, view videos and read pithy passages about self-empowerment. It’s a daring, big-budget move for the museum and one that is sure to change its public profile.