Pivotpunkten

Pivotpunkten refers to the fixed point around which an object rotates or undergoes a transformation. In mechanics, it is the axis or hinge that defines the center of rotation for a lever, door, crank, or similar mechanism. In computer graphics, robotics and animation, the pivotpunkten is the origin of the object’s local coordinate system and determines how rotation, scaling and other transforms are applied relative to the scene or to parent objects. The term is commonly used interchangeably with rotation origin or origin in modelling and animation software.

In practice, the location of the pivotpunkten matters a great deal. A misaligned pivot can cause intuitive but unintended movements, such as a door rotating about the wrong edge or a character spinning unnaturally around a misplaced joint. Designers choose the pivotpunkten to approximate physical behavior or to achieve a desired visual effect. Some objects have a fixed pivot, while others use a movable pivot that can shift during an animation or a sequence.

A simple mathematical view is that rotating a point (x, y) around a pivotpoint (x0, y0) by angle theta yields (x', y') = (x0 + cos(theta)(x − x0) − sin(theta)(y − y0), y0 + sin(theta)(x − x0) + cos(theta)(y − y0)). This formula underpins many software tools' rotate operations and helps explain how the pivotpunkten governs the outcome of transformations.

See also: origin, axis, hinge, centre of rotation.