LUMIERA.clone/doc/design/workflow/Verwijlen/FrosconMeeting.txt

Meeting at FrOSCon 2025
=======================
Date: 2025-08-17
Author: Benny Lyons and Hermann Voßeler
:toc:

Present::
- Wouter Verwijlen
- Benny Lyons
- Hermann Voßeler

Endgoal::
  To produce a design document.

This Meeting is based on the document link:TODO[»Lumiera Workflow Proposals«] by Wouter Verwijlen.
Wouter travelled to FrOSCon to meet the core team in person. This meeting discussed some central points
of the planned workflow support in the Lumiera GUI. We discussed problems, agreed on various points
and decided to produce a design document. Here we attempt to reconstruct and document the original meeting.

Points discussed
----------------
We agreed upon the importance of a _Magnetic Timeline,_ as introduced by Final Cut X. However, our
Placement concept [TODO Link] which predates FCX's release [TODO source] shares similar goals but
its scope is more far-reaching. We consider _Magnetic Timeline_ to be an important advancement to
legacy track oriented GUI schemes; but it is more mouse confined and does not support several Control
Systems footnote:[Mouse, keyboard, pen, hardware controls] on an equal footing, which is our vision.

Modes, Tools and Views
~~~~~~~~~~~~~~~~~~~~~~
Modes are generally frowned upon in the User Interface Design discipline. On the other hand, they enjoy
popularity in video editing applications. Tools and Views were introduced to improve the usability
of Modes. We agreed to adopt tools as the more preferable system, but only if we manage to develop
a suitable handling mechanism that can be used naturally throughout all Control Systems.

Taking inspiration from Blender, Hermann proposed a fundamental shift by extending the scope of tool usage
to the entire UI. To do this, we agreed to introduce a top-level tool to navigate throughout the UI.
Wouter expressed some concerns on how effect parameters and mixer stripes could be accessed. This
remains a problem to be resolved. We agreed that this default navigation tool should map down
naturally to conventional usage of the mouse.

We discussed that a consequence of that decision might be to introduce a special tool dedicated
to dragging and moving clips, but we were concerned that such a mode might hamper fluid working
with the UI. It seems preferable to introduce the moving of clips as a sub-mode into the 
navigation tool, with the option to lock moving of clips.

Wouter introduced a context sensitive tool palette which is rendered as an overlay in the timeline UI.
The ability of Tools to support sub-modes is a simple extension of this proposal. 
With this functionality, it would be then be possible to switch between trim-, roll-, slide- and shuffle-edit
after activating the edit tool. Similarly, the _gear switch_ as proposed in a previous online discussion
would be integrated as a sub-mode if a user decided to manipulate any setting value.

Internatinalisation
~~~~~~~~~~~~~~~~~~~
The language of the UI is English. This does not mean that we exclude any language
(all contributions are welcome). Certain words and terminology should never be translated, e.g.,
Track, Clip, Placement, ... . We also do not support translations that require a re-ordering
of UI elements such as languages written right-to-left. This is due to priorities that we define.


Unlimited Placement Constraints
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The use of fine-grained placement constraints is plagued with overwhelming the user with 
excessive relationships. This can be improved by using a small number of prototype set-ups:
magnetic, relative and music anchored. Moreover, we require a diagnostic to reveal the reason why 
a given clip is positioned at where it is.

Routing
^^^^^^^
Hermann explained how the routing in Render Engine is based on Placements.
All data streams are grouped according to the medium (video, audio,...) by default.
Mixing-groups can be automatically established if resources are tagged.


Layering order
~~~~~~~~~~~~~~
The layering order is usually arranged according to track sequence in the UI.
To retain this configuration we would have to put some content into a track which can be
located at a distance from other related content: not an ideal situation. One way to alleviate
this problem is to allow the user to configure the layer ordering for a single track so that
all content is always fixed to be above a reference clip. While this promises to be an
interesting mechanism to improve the track sequence dilemma and provide the user a greater
track arrangement freedom, further practical tests need to be carried out to determine its
feasibility.

Grouping Devices
~~~~~~~~~~~~~~~~
One idea presented in Wouters document was the introduction of a light-weight grouping device.
This would solve some problems, for example, a number of objects can be collectively moved
as one unit together. Hermann proposed to use placements to achieve the same effect.
It is yet to be resolved how this grouping can be visually represented.

One important issue proposed by Wouter was to use segments to arrange the narrative at the
top level. To implement this feature would require on the one hand a considerable effort
by developers, on the other hand, it does not naturally fit into the Lumiera core design
as it would be a very specific extension instead of a homogeneous building block in Lumiera.
Hermann proposes to use nested sequences to implement this feature which is already been
planned for the session model. All these nested sequences will have their own track structure,
which is a tree relationship. For example, expanding one structure would not necessarily
expand neighbouring structures. Another advantage of using this mechanism is that it can
be used to construct a transition between adjacent chapters of a film while still retaining
the ability to reshuffle chapters to explore various narratives. We can thus solve two
problems with the same feature.

Wouter was concerned that it might be tedious to navigate between different chapters,
especially if it is necessary to expand or collapse these elements repeatedly. One
countermeasure to releave constant opening and closing elements would be to expand
the elements stepwise while still retaining the ability to edit the contents.


Target audience
~~~~~~~~~~~~~~~


Conclusions
-----------