.. _context:

Context
=======


Context provide the ability to select "snappable" items and create snap helpers from selected items, like intersections / perpendicular, average, see :ref:`helpers`.


Select items
------------

.. important::
    | In order to select snappable items, you must hold **SHIFT** 
    | while pressing left mouse over an active snap item (highlight yellow).


Remove selected items
---------------------

| In order to remove last selected item, use **BACK SPACE**.
| To remove all items, use **SHIFT + BACK SPACE**


Evaluate context and add new helpers
------------------------------------

.. important::
    | Context evaluation depends on the view : 
    | In orthographic view you'll get intersections based on view angle
    | In perspective view, you'll get closest points 

Usage : select items, then use shortcut **H** for helpers, **A** for average

* Line / line intersection, require at least 2+ lines
* Line / plane intersection, require one line and a face
* Nearest point on line / plane (perpendicular), require one point and one line
* Nearest point on plane (perpendicular, require one point and a face
* Line between 2 points, require 2 points
* Face normal, require one face
* Average of selected points location (shortcut **A**) require at least one item