Key Features

Overview

Mixer synchronizes in real time the modifications done to the scene and the objects it contains. During a collaboration session, Mixer displays the position of other participants and highlights their selections. See Work together for more details.

In the sections bellow we listed the features of Blender that are synchronized and those which are volontary not, as well as what is currently supported and what is not.

Warning

Undo / Redo is a important pitfall at the moment for technical as well as paradigm reasons. It is strongly adviced not to use it, it may destabilize the running collaborative session.

See Caveats for more details.

What is synchronized

Most of the elements contained in a scene, the data types, are synchronized, as well as the custom properties of all datablocks. The following table summarizes the covered features and a note indicates when synchronization is not available because the feature has not been implemented yet.

Data	Status	Comments
Action	Yes	See [Delay]
Armature	Partial	Simple rigs only. See [Armature]
Brush	No
Collection	Partial	Except collection children ordering
Camera	Yes
Curve	Partial	Except surface and Bézier curves. See [Edit], [Convert]
Grease pencil	Yes	See [GreasePencil], [Edit], [Convert]
Image	Partial	See [Image], [Media]
Keying sets	No
Library	Partial	See [Library]
Light	Yes
Light probe	No
Line style	No
Mask	No
Material	Yes	See [Nodes]
Mesh	Partial	Except split normals, custom properties, see [Edit]
Metaball	Yes	See [Edit], [Convert]
Movie clip	Yes	See [Media]
Node group	Partial	Not extensively tested, see [Nodes]
Object	Partial	Except motion paths, particles and physics. See [Convert]
Paint curve	No
Particles	No
Shape key	Yes
Scene	Yes	See [Delay]
Sound	Yes	See [Media]
Text	No
Texture	Yes
Volume	No
VSE	Partial	Except meta strips. Not extensively tested
World	Yes

Armature

Issues remain with rigs generated by Rigify.

Convert(1,2,3,4)

The result of object conversion (Object/Convert to menu) is not synchronized.

Delay(1,2)

Some updates may be delayed until another modification is detected:

• scene annotations: try to click around in the background of the 3D viewport

• animation curves names : try to toggle the curve Enable checkbox twice.

Edit(1,2,3,4)

While an object is not in Object mode (in Edit, Sculpt, Paint, …) the local modifications to this object are not sent to the other participants and the other participants modifications are not applied. Pending modifications are applied when the mode changes.

GreasePencil

• the mask layer is not correctly synchronized

• area fill is sometimes not correct

Image

Generated images and UDIMs are not synchronized. Image files are synchronized.

Library

Nested libraries will fail when shared folders are not in use. The following are not synchronized:

• the results of make local and reload

• library overrides

Media(1,2,3)

Media files are synchronized. The result of reload or media path modification are not synchronized.

Nodes(1,2)

Links synchronization sometimes fails. Some cases might cause crashes.

What is NOT synchronized

In order to provide to all participants a collaborative experience with as much freedom as they have during a solo session some features are deliberately not synchronized. This is the case for most User Interface elements, user preferences and configuration.

UI and Settings	Comments
User preferences
Key mapping
Installed add-ons
Workspace

Scene Manipulation	Comments
Object Editing Mode
Active tool	Eg: Move, Rotate, Scale…
3D cursor
Scene display mode	Show gizmos, overlays…
Viewport shading
Play mode

Scene Properties	Comments
Scene current camera	See [SceneCurrentCamera]
Render engine	See [RenderEngine]

SceneCurrentCamera

Although belonging to the scene properties, preventing the current camera to be synchronized allows each user to view and render the scene from the camera of her choice

RenderEngine

Each user can render either with Eevee, Cycle or another avaiable engine of her choice

Caveats

In addition to the limitations listed in the previous section, you should be aware of the following limitations:

Undo / Redo

Using undo may cause data desynchronisation between users, unexpected behaviors and possibly some crashes. Using undo while in Object mode may undo other participants changes. It is then strongly adviced not to use the undo feature during a collaborative session.

The undo action rises several paradigm questions such as:

• What happens in the scene when an action is undone and some work dependent on it has been done by other users, such as a mesh edit, a constraint, etc?

• What should be undone? The last action of the user doing the step backward or the last action made by any user of the session? Or all the actions of everyone up to the last action of the considered user?

• Should a redo be possible?

• …

Once the expected behavior clearly defined there is a technological challenge to face in order to address it.

Currently the undo and redo actions are “possible” as part of the default behavior of Blender. For the reasons mentioned above doing one of them can very likely, according to the context, lead to an unstable environment. It can be noticed from error messages in the terminal or more obviously from differences in terms of data in the shared scene.

At this point a synchronisation recover is unlikely and it is adviced that one of the users save the scene on her computer, everyone leaves the room and a new session is started.

In order to minimize the chances of doing an undo action we thought about blocking this feature during a session. We don’t know if this is possible and have not gone further in that direction at the moment.

File saving

The files saved by all participants are not exactly identical.