A rendering engine is described that implements rendering techniques to render 2D illustrations by assigning light values to objects that define an illustration ‘inside out’. Light values may be assigned to a first object and subsequently inherited by objects that are hierarchly related to the first object. The light values assigned to the objects may include a light variable that depends on a relationship between the two or more groups of objects. Various rendering techniques may be employed by the rendering engine to render illustrations that are both customizable and realistic in appearance.