Alembics and hair... very finnicky from blender [CRASHES EDITOR]

Unity Engine
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1

2022.3.10, alembic 2.3.4, tested both standard and URP and the latest LTS and with older versions of alembic importer (but mainly in URP and on .3.10 and 2.3.4 importer)

At first when just creating a hair object in blender 3.6 with their new hair system and exporting as alembic it would straight up crash the editor when I imported it. If it didn’t crash it would just show a missing script error saying it couldn’t load the asset.

So I switched to blender 4.0, got rid of any hair plugins (was using BGEN grooming addon), created vanilla hair asset, imported alembic, still no curves being read (both fluffy asset and preview unity demo team hair system).

I swear I tried everything on planet earth, in a fit of rage I converted the hair asset to a mesh, then back into a curve in blender 4.0.

Now it is working in Unity.

For the poor soul who might stumble on this one day, I grant thee my gift of knowledge, I banged the two rocks together and found the flint. You may now create the fire. Go forth into the world my child.

2

Interesting! Sounds like Blender smooths itself over from the convert-convert operation.

FYU, Unity just launches Blender with a little python script to do the import … you should be able to mimic that at the command line and see a complete log of how Blender barfs.

Unity imports Blender3D objects as FBX via a little Python script:

https://discussions.unity.com/t/832303/2

The Python script that Unity uses (substitute your Unity version number or search) to import:

./Hub/Editor/2020.2.1f1/Unity.app/Contents/Tools/Unity-BlenderToFBX.py

3

Thanks for the tip. Converting to mesh then converting back to curve fixed the crash when importing in Unity.

4

Confirmed with another lost soul! You shall be our chosen one, praise be the solution.