A door is a movable barrier that allows or blocks access to a space. It can be opened, closed, or partially open, but we still perceive it as the same shape.
Related terms
Perceptual Constancy: Our ability to perceive objects as having consistent size, shape, color, and brightness even when they appear differently due to changes in viewing conditions.
Size Constancy: The tendency to perceive an object as maintaining its size despite changes in its retinal image caused by distance variations.
Shape Constancy: The tendency to perceive an object as maintaining its shape despite changes in its orientation or appearance from different viewpoints.