Exported Alembic of Linked Collections: Instances Jumping Around #84725

New Issue

John Cox · 2021-01-14T22:54:44+01:00

John Cox commented

2021-01-14 22:54:44 +01:00

System Information
Operating system: Win 10
Graphics card: RTX3080

Blender Version
2.91

Short description of error

Exact steps for others to reproduce the error
I have a scene made of collection instances linked from another file.
When I export to Alembic and import in another app or back into 2.91, I end up with one instance of
each collection interpolating between the locations of all the instances in the original file.

Its like there is one copy of the collection and it is seeing the transform of each instance as a keyframe and
jumping to every position during playback.

Maybe important: I created multiple instances by duplicating (SHIFT - d) the first linked instance rather
than adding more through the Add Object menu.

Open a new scene
Import attached file
Scrub timeline

The jumping objects are by the buildings halfway up the mountain.

The original blend is too big to upload but can be shared if you need it.

TEST_assembly.abc

**System Information** Operating system: Win 10 Graphics card: RTX3080 **Blender Version** 2.91 **Short description of error** **Exact steps for others to reproduce the error** I have a scene made of collection instances linked from another file. When I export to Alembic and import in another app or back into 2.91, I end up with one instance of each collection interpolating between the locations of all the instances in the original file. Its like there is one copy of the collection and it is seeing the transform of each instance as a keyframe and jumping to every position during playback. Maybe important: I created multiple instances by duplicating (SHIFT - d) the first linked instance rather than adding more through the Add Object menu. Open a new scene Import attached file Scrub timeline The jumping objects are by the buildings halfway up the mountain. The original blend is too big to upload but can be shared if you need it. [TEST_assembly.abc](https://archive.blender.org/developer/F9579495/TEST_assembly.abc)

John Cox commented

2021-01-14 22:54:44 +01:00

Added subscriber: @JohnCox-3

Philipp Oeser commented

2021-02-01 17:50:43 +01:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2021-02-01 17:50:43 +01:00

Changed status from 'Needs Triage' to: 'Needs User Info'

Philipp Oeser commented

2021-02-01 17:50:43 +01:00

To speed up the the triaging process as much as possible, it would be good to have a minimal example case with just one source instance (duplicated a couple of times) to reduce complexity.
In the meantime, we would at least need the source .blend file (where the .abc was exported from).
This ensures we are all on the same page and reduces setup time if multiple devs are looking at this.

To speed up the the triaging process as much as possible, it would be good to have a minimal example case with just one source instance (duplicated a couple of times) to reduce complexity. In the meantime, we would at least need the source .blend file (where the .abc was exported from). This ensures we are all on the same page and reduces setup time if multiple devs are looking at this.

John Cox commented

2021-02-01 19:19:16 +01:00

I think this contains all you need to investigate this LinkedAssetAlembicBug.zip

Let me know if there is any more info required

I think this contains all you need to investigate this [LinkedAssetAlembicBug.zip](https://archive.blender.org/developer/F9607982/LinkedAssetAlembicBug.zip) Let me know if there is any more info required

Philipp Oeser commented

2021-02-19 15:31:02 +01:00

Changed status from 'Needs User Info' to: 'Needs Triage'

Philipp Oeser commented

2021-02-19 15:31:02 +01:00

Sorry this has been lying around, will have another look soonish

Philipp Oeser commented

2021-02-24 11:19:18 +01:00

Changed status from 'Needs Triage' to: 'Confirmed'

Philipp Oeser commented

2021-02-24 11:19:18 +01:00

Ok, sorry again this took a bit to answer, but I can confirm.

In fact, choosing Flatten Hierarchy in concert with instances seems to have problems in general (dont even have to add linking to the mix), but lets keep this for a separate report.

Seems like ObjectIdentifier ObjectIdentifier::for_graph_root() returns the same for different instances?

Ok, sorry again this took a bit to answer, but I can confirm. In fact, choosing `Flatten Hierarchy` in concert with instances seems to have problems in general (dont even have to add linking to the mix), but lets keep this for a separate report. Seems like `ObjectIdentifier ObjectIdentifier::for_graph_root()` returns the same for different instances?

Philipp Oeser removed the

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

Exported Alembic of Linked Collections: Instances Jumping Around #84725