build123d/docs/location_arithmetic.rst

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.. _location_arithmetics:
Location arithmetic for algebra mode
======================================
Position a shape relative to the XY plane
---------------------------------------------
For the following use the helper function:
.. code-block:: python
def location_symbol(location: Location, scale: float = 1) -> Compound:
return Compound.make_triad(axes_scale=scale).locate(location)
def plane_symbol(plane: Plane, scale: float = 1) -> Compound:
triad = Compound.make_triad(axes_scale=scale)
circle = Circle(scale * .8).edge()
return (triad + circle).locate(plane.location)
1. **Positioning at a location**
.. code-block:: python
loc = Location((0.1, 0.2, 0.3), (10, 20, 30))
face = loc * Rectangle(1,2)
show_object(face, name="face")
show_object(location_symbol(loc), name="location")
.. image:: assets/location-example-01.png
2) **Positioning on a plane**
.. code-block:: python
plane = Plane.XZ
face = plane * Rectangle(1, 2)
show_object(face, name="face")
show_object(plane_symbol(plane), name="plane")
.. image:: assets/location-example-07.png
Note that the ``x``-axis and the ``y``-axis of the plane are on the ``x``-axis and the ``z``-axis of the world coordinate system (red and blue axis)
Relative positioning to a plane
------------------------------------
1. **Position an object on a plane relative to the plane**
.. code-block:: python
loc = Location((0.1, 0.2, 0.3), (10, 20, 30))
face = loc * Rectangle(1,2)
box = Plane(loc) * Pos(0.2, 0.4, 0.1) * Box(0.2, 0.2, 0.2)
# box = Plane(face.location) * Pos(0.2, 0.4, 0.1) * Box(0.2, 0.2, 0.2)
# box = loc * Pos(0.2, 0.4, 0.1) * Box(0.2, 0.2, 0.2)
show_object(face, name="face")
show_object(location_symbol(loc), name="location")
show_object(box, name="box")
.. image:: assets/location-example-02.png
The ``x``, ``y``, ``z`` components of ``Pos(0.2, 0.4, 0.1)`` are relative to the ``x``-axis, ``y``-axis or
``z``-axis of the underlying location ``loc``.
Note: ``Plane(loc) *``, ``Plane(face.location) *`` and ``loc *`` are equivalent in this example.
2. **Rotate an object on a plane relative to the plane**
.. code-block:: python
loc = Location((0.1, 0.2, 0.3), (10, 20, 30))
face = loc * Rectangle(1,2)
box = Plane(loc) * Rot(z=80) * Box(0.2, 0.2, 0.2)
show_object(face, name="face")
show_object(location_symbol(loc), name="location")
show_object(box, name="box")
.. image:: assets/location-example-03.png
The box is rotated via ``Rot(z=80)`` around the ``z``-axis of the underlying location
(and not of the z-axis of the world).
More general:
.. code-block:: python
loc = Location((0.1, 0.2, 0.3), (10, 20, 30))
face = loc * Rectangle(1,2)
box = loc * Rot(20, 40, 80) * Box(0.2, 0.2, 0.2)
show_object(face, name="face")
show_object(location_symbol(loc), name="location")
show_object(box, name="box")
.. image:: assets/location-example-04.png
The box is rotated via ``Rot(20, 40, 80)`` around all three axes relative to the plane.
3. **Rotate and position an object relative to a location**
.. code-block:: python
loc = Location((0.1, 0.2, 0.3), (10, 20, 30))
face = loc * Rectangle(1,2)
box = loc * Rot(20, 40, 80) * Pos(0.2, 0.4, 0.1) * Box(0.2, 0.2, 0.2)
show_object(face, name="face")
show_object(location_symbol(loc), name="location")
show_object(box, name="box")
show_object(location_symbol(loc * Rot(20, 40, 80), 0.5), options={"color":(0, 255, 255)}, name="local_location")
.. image:: assets/location-example-05.png
The box is positioned via ``Pos(0.2, 0.4, 0.1)`` relative to the location ``loc * Rot(20, 40, 80)``
4. **Position and rotate an object relative to a location**
.. code-block:: python
loc = Location((0.1, 0.2, 0.3), (10, 20, 30))
face = loc * Rectangle(1,2)
box = loc * Pos(0.2, 0.4, 0.1) * Rot(20, 40, 80) * Box(0.2, 0.2, 0.2)
show_object(face, name="face")
show_object(location_symbol(loc), name="location")
show_object(box, name="box")
show_object(location_symbol(loc * Pos(0.2, 0.4, 0.1), 0.5), options={"color":(0, 255, 255)}, name="local_location")
.. image:: assets/location-example-06.png
Note: This is the same as `box = loc * Location((0.2, 0.4, 0.1), (20, 40, 80)) * Box(0.2, 0.2, 0.2)`