This patch adds a new Compositor modifier that applies a compositing
node group on a sequencer strip. This patch also introduces the concept
of a compositor node tree space subtype, where we now have a Scene and a
Sequencer subtypes. Practically, this just means that node like the
Render Layers node will not be available in the node editor in the
Sequencer subtype.
Future improvements includes:
- The compositor context is recreated on every modifier application,
while it should ideally be persistent somehow to make use of the
compositor static cache. This might require work from the compositor
side by moving the static cache outside of the context and make it
thread safe if needed. See `Render.compositor` for an example on
persistent context.
- GPU execution is not supported. This just needs a GPU context to be
bound before execution, but the tricky part is getting a GPU context.
See `render::Compositor::execute` for an example on bounding a GPU
context and why it is less straight forward.
- Node inputs are not exposed on the sequencer modifier interface. An
approach similar to Geometry Nodes modifier could be used, look at
`update_input_properties_from_node_tree` for reference, but notice
that Geometry Nodes naturally exempt the main Geometry socket because
Geometry inputs can't be exposed, but for the compositor, we will have
to exempt the main Color and Mask sockets manually. !145971
Co-authored-by: Aras Pranckevicius <aras@nesnausk.org>
Co-authored-by: Falk David <falk@blender.org>
Pull Request: https://projects.blender.org/blender/blender/pulls/139634