.. _auto_curves_three_point_rotation:

*FIND THE TIME-HISTORY ANGLE USING TIME-HISTORY COORDINATES OF THREE POINTS*
============================================================================

Computes the time-history of the angle (in degrees or radians) formed at an origin point by two vectors defined from three time-varying 3-D coordinate curves. Use this worker whenever you need to track the rotation angle between two structural directions over a simulation time history.

When to use
-----------

Classification: **process**.

Tagged: ``3d_coordinates``, ``angle``, ``degrees``, ``kinematics``, ``radians``, ``rotation``, ``three_point_rotation``, ``time-history``.

Inputs
------

.. list-table::
   :header-rows: 1
   :widths: 20 20 20 20 20 20

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Point 1 XYZ
     - point1xy_z
     - vector
     - —
     - 
     - Origin point XYZ time-history curve (vector of [t, x, y, z] or equivalent); defines the apex of the angle from which both vectors originate.
   * - Point 2 XYZ
     - point2xy_z
     - vector
     - —
     - 
     - Second point XYZ time-history curve (vector); together with Point 1 this defines the first direction vector (Point1 → Point2) at each time step.
   * - Point 3 XYZ
     - point3xy_z
     - vector
     - —
     - 
     - Third point XYZ time-history curve (vector); together with Point 1 this defines the second direction vector (Point1 → Point3) at each time step.
   * - Return Type
     - return_type
     - string
     - deg
     - 
     - Unit of the output angle — 'deg' (degrees, default) or 'radians'; leave as 'deg' unless downstream workers require radians.

Outputs
-------

.. list-table::
   :header-rows: 1
   :widths: 20 20 20 20

   * - Label
     - ID
     - Type
     - Description
   * - curves_three_point_rotation_output_1
     - curves_three_point_rotation_output_1
     - vector
     - Time-history curve of the angle between the two vectors (Point1→Point2 and Point1→Point3), expressed in the unit selected by return_type (degrees by default).

Disciplines
-----------

- data.curve.transform
- data.signal_processing
- engineering.crash.dynamics
- engineering.multibody

Runnable example
----------------

A runnable example is registered for this worker. Open the example workflow on the d3VIEW canvas: `/api/workflow/example?id=curves_three_point_rotation <https://www.d3view.com/api/workflow/example?id=curves_three_point_rotation>`_

.. raw:: html

   <hr style="margin-top:2em">
   <p style="font-size:11px;color:#888">
   Auto-generated from <code>transformation</code> schema. Worker id: <code>curves_three_point_rotation</code>. Schema hash: <code>7c88a14468fe</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
   </p>