Find out how shadows are formed and what types of materials produce shadows. Physical processes - Light - Shadows Learning Points Shadows are created when an object blocks the path of light. Opaque objects do not let any light through. Translucent objects let some light through. Transparent objects let all light through. A Twig Curriculum Film. Delivering key learning points. Get straight to the facts in just three minutes – directly linked to core learning, Twig's curriculum films will fit neatly into your lesson plans.