.. currentModule:: Autograph

.. _rendering:

Creating Renders
=================

To render a video/image sequence on disk, the main API to use is the :class:`RenderManager` that can be accessed from :meth:`Project.getRenderManager()`

The :class:`RenderManager` acts as a queue of :class:`CompRender` and can start rendering them.

A :class:`CompRender` defines a list of :class:`CompRenderInstance` to render for a given :class:`Composition`.

Each :class:`CompRenderInstance` defines all parameters of a :class:`Composition` to be rendered. The render instance contains a list of :class:`CompRenderFile`.

Each :class:`CompRenderFile` in the list will then take the output of the render and encode it to the appropriate image/video file. This architecture is useful to render the same Composition with the same parameters in various output formats/codecs.

Let's see an example to setup a Quicktime ProRes render of a composition in Full HD:


.. code-block::

	project=Autograph.app.getActiveProject()
	comp=project.getItemByName("Composition").getMainEffectInstance()

	rm= project.getRenderManager()

	render=Autograph.CompRender()
	render.setComposition(comp)

	instance=Autograph.CompRenderInstance()
	render.insertInstance(instance)

	file=Autograph.CompRenderFile();
	instance.insertFile(file)

	# or in a one-liner:
	(render, instance, file) = rm.createRenderForComposition(comp)

	instance.setFormat(1920, 1080)

	file.filePathOverride = '/Users/<user>/tmp/myVideo.mov'

	file.fileFormat = 'mov'
	file.videoCodec = 'prores'
	file.setProperty('prores_profile', 'PR_422HQ')

	rm.insertRender(render)

	# If True, blocks until finished
	rm.startRenders(True)


Reacting to render events
-------------------------

It may be useful to execute specific code when certain events are triggered, such as when a frame is rendered or when a render is finished.

The :meth:`RenderManager.onRenderFinished` callback is invoked when all :class:`CompRender` are finished. This is useful to know that Autograph is finished rendering the whole queue.

You may be notified of the progress evolution of each :class:`CompRender` with the :meth:`CompRender.onProgressChanged` callback.

The :meth:`CompRenderFile.onFrameRendered` callback is invoked when a frame is rendered and passes in parameter the file that was just written. It also triggers at the same time the :meth:`CompRenderFile.onProgressChanged` callback.

The :meth:`CompRenderFile.onRenderFinished` callback is invoked when the full sequence/video is finished rendering. This may be useful to trigger custom pipeline to e.g: upload the file to a server.

The :meth:`CompRenderFile.onRenderStarted` callback is invoked when Autograph starts rendering this file in the queue.