****************
Scene Properties
****************

Scene
=====

Camera
   Used to select which camera is used as the active camera.

.. _scene-background-set:

Background
   Allows you to use a scene as a background,
   this is typically useful when you want to focus on animating the foreground for example,
   without background elements getting in the way.

   This scene can have its own animation, physics-simulations etc,
   but you will have to select it from the *Scene* data-block menu, if you want to edit any of its contents.

   .. tip::

      This can also be used in combination with :ref:`Linking to a Scene <data-system-linked-libraries-make-link>`,
      where one blend-file contains the environment, which can be re-used in many places.

Active Clip
   Active movie clip for constraints and viewport drawing.


.. _data-scenes-props-units:

Units
=====

Length Presets
   Common unit scales to use.
Length
   None
      Uses :term:`Blender Units`.
   Metric, Imperial
      Standard unit of measurement for lengths.
Angle
   Standard unit for angular measurement.

   Degrees, Radians

   .. tip::

      When you are using *Degrees*, the radian value is also displayed in the tooltip.

Unit Scale
   Scale factor to use when converting between :term:`Blender Units` and *Metric*/*Imperial*.

   .. tip::

      Usually you will want to use the *Length* presets to change to scale factor,
      as this does not require looking up values to use for conversion.

Separate Units
   When *Metric* or *Imperial* display units as multiple multiple values,
   for example, "2.285m" will become "2m 28.5cm".

.. Normally we would avoid documenting long lists of values
   however, this is not displayed anywhere else.

.. list-table:: Imperial Units
   :header-rows: 1
   :stub-columns: 1

   * - Full Name
     - Short Name(s)
     - Scale of a Meter
   * - thou
     - ``mil``
     - 0.0000254
   * - inch
     - ``"``, ``in``
     - 0.0254
   * - foot, feet
     - ``'``, ``ft``
     - 0.3048
   * - yard
     - ``yd``
     - 0.9144
   * - chain
     - ``ch``
     - 20.1168
   * - furlong
     - ``fur``
     - 201.168
   * - mile
     - ``mi``, ``m``
     - 1609.344

.. list-table:: Metric Units
   :header-rows: 1
   :stub-columns: 1

   * - Full Name
     - Short Name(s)
     - Scale of a Meter
   * - micrometer
     - ``um``
     - 0.000001
   * - millimeter
     - ``mm``
     - 0.001
   * - centimeter
     - ``cm``
     - 0.01
   * - decimeter
     - ``dm``
     - 0.1
   * - meter
     - ``m``
     - 1.0
   * - dekameter
     - ``dam``
     - 10.0
   * - hectometer
     - ``hm``
     - 100.0
   * - kilometer
     - ``km``
     - 1000.0


Keying Sets
===========

See :doc:`/animation/keyframes/keying_sets`.


Color Management
================

Options to control how images appear on the screen.

For :ref:`Color Management settings <render-post-color-management>` for more information.


.. move to audio rendering?

.. _data-scenes-audio:

Audio
=====

Options to control global audio settings.

Volume
   Volume for the scene.
Update Animation Cache
   Updates the audio animation cache. This is useful if you start noticing artifact in the audio.


Distance Model
---------------------

Distance Model
   TODO.

Speed
   Speed of the sound for the Doppler effect calculations.
Doppler
   Pitch factor for Doppler effect calculation.


Format
----------

Channels
   TODO.
Mix Rate
   TODO.


Gravity
=======

Options to control global gravity used for physic effects.

See the :ref:`Physics Introduction <physics-intro-gravity>` for more information.


Rigid Body World
================

The *Rigid Body World* is a group of Rigid Body objects,
which holds settings that apply to all rigid bodies in this simulation.

See :doc:`Rigid Body World </physics/rigid_body/world>` for more information.


.. todo move to render/settings - engine dependent

Simplify
========

Subdivision
   Maximum number of *Viewport*/*Render* subdivisions to use for the
   :doc:`Subdivision Modifier </modeling/modifiers/generate/subsurf>`

Child Particles
   Percentage of :doc:`Child Particles </physics/particles/emitter/children>`
   to see in the *Viewport*/*Render*.

Use Camera Cull
   Automatically culls objects based on the camera frustum.

   Margin
      Margin for the camera space culling.