.. Copyright (c) 2008-2016 OpenShot Studios, LLC
 (http://www.openshotstudios.com). This file is part of
 OpenShot Video Editor (http://www.openshot.org), an open-source project
 dedicated to delivering high quality video editing and animation solutions
 to the world.

.. OpenShot Video Editor is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

.. OpenShot Video Editor is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

.. You should have received a copy of the GNU General Public License
 along with OpenShot Library.  If not, see <http://www.gnu.org/licenses/>.

.. _animation_ref:

Animation
=========

OpenShot has been designed specifically with animation in mind. The powerful curve-based animation framework can
handle most jobs with ease, and is flexible enough to create just about any animation. Key frames specify
values at certain points on a clip, and OpenShot does the hard work of interpolating the in-between values.

Overview
--------

.. image:: images/animation-overview.jpg

.. table::
   :widths: 5 32

   ==  ==================  ============
   #   Name                Description
   ==  ==================  ============
   1   Green Property      When the play-head is on a key frame, the property appears green
   1   Blue Property       When the play-head is on an interpolated value, the property appears blue
   2   Value Slider        Click and drag your mouse to adjust the value (this automatically creates a key frame if needed)
   3   Play-head           Position the play-head over a clip where you need a key frame
   4   Key frame Markers   Small green tick marks are drawn at all key frame positions (on a clip)
   ==  ==================  ============

Key Frames
----------
To create a key frame in OpenShot, simply position the play-head (i.e. playback position) at any point over a clip,
and edit properties in the property dialog. If the property supports key frames, it will turn green, and a small green
tick mark will appear on your clip at that position. Move your play-head to another point over that clip, and adjust
the properties again. All animations require at least 2 key frames, but can support an unlimited number of them.

To adjust the **interpolation mode**, right click on the small graph icon next to a property value.

.. table::
   :widths: 12

   ==================  ============
   Name                Description
   ==================  ============
   Bézier              Interpolated values use a quadratic curve, and ease-in and ease-out
   Linear              Interpolated values are calculated linear (each step value is equal)
   Constant            Interpolated values stay the same until the next key frame, and jump to the new value
   ==================  ============

For more info on clip properties, see :ref:`clip_properties_ref`. For more info on preset animations, see :ref:`clip_presets_ref`.

The :ref:`Keyframe Interpolation Appendix<keyframe_interpolation_ref>` has much more detailed information.

Bézier Presets
--------------
When using a Bézier curve for animation, OpenShot includes more than 20 curve presets (which affect the shape
of the curve). For example, **Ease-In** has a more gradual slope at the beginning, making an animation move slower at
the beginning, and faster at the end. **Ease-In/Out (Back)** has a gradual beginning and ending, but actually goes past
the expected value and then back (producing a bounce effect).

To choose a curve preset, right click on the small graph icon next to a key frame.

.. image:: images/curve-presets.jpg



Other
-----

OpenShot can import a sequence of images to be used as an animation, and also creates animated titles in this way.

Please see the the section on :ref:`Image Sequences<image_sequences_ref>`.

[note: this whole animation section needs revision, with much more detail]