Alembic Explicit Normals lost?

[Gregory]

I am trying to get a Tyflow Alembic animated mesh into Unreal, but no matter what I do, the explicit normals are getting lost in Unreal.
Is there any way I can retain them when exporting from Tyflow?
Any ideas?

Thanks,
Greg

[tyFlow]

What do your unreal import settings look like?

[Gregory]

What do your unreal import settings look like?

Pretty much default settings; I've tried every possible combination there is.

---

Tried "Force One Smoothing Group per Object", as well as "Recompute Normals"; no change whatsoever.

[tyFlow]

Hmm, can you send me the Alembic file and/or Max file to examine?

[Gregory]

Hmm, can you send me the Alembic file and/or Max file to examine?

Sure, here is both generated alembic and max file will all settings:
https://www.dropbox.com/scl/fi/o965spvsp...x2jj9&dl=0
Using both latest Max 2024 and Tyflow...
Hope you can get to the bottom of this!

[tyFlow]

Thanks, looks like I forgot to update the Alembic mesh when explicit normal support was added to tyFlow, so explicit normals are not being exported. This will be fixed in the next tyFlow build (v1.112) which should be out soon.

[Gregory]

Thanks, looks like I forgot to update the Alembic mesh when explicit normal support was added to tyFlow, so explicit normals are not being exported. This will be fixed in the next tyFlow build (v1.112) which should be out soon.

Thanks Tyson.
That was super fast!
Very much appreciated!

[Gregory]

Hm...
Still can't get it to work; I'm getting no explicit normals in UE.
Is there anything perhaps I should do differently?
Or, is it UE that cannot handle explicit normals at first place?

[tyFlow]

Hmm, you know what, I may have jumped the gun on claiming the issue was fixed...I was verifying my changes with some simpler test geometry and the normals were exported correctly, but now that I re-verify with your original geo (something I forgot to do), the normals are not coming through. I'll need to do some further digging to figure out what's going on...

[Gregory]

Thanks Tyson.
I may have to figure another workaround to do this, cause my deadline for this project is next Friday; build a whole car using this effect, and port into UE for rendering.
If you want me to test any intermediate beta build or something, let me know, i'll be happy to do so.

[tyFlow]

I'll have an update for you in a few minutes here, I believe I found the problem.

[tyFlow]

Here's frame 75 re-exported with the potential fix...does it come through with explicit normals in Unreal?

[tyFlow]

I've updated the latest v1.112 zip file to include that fix as well, so you can re-download the latest build to get it.

[Gregory]

Apologies, somehow I did not got a notification with your replies!
I just checked and I can confirm the issue is gone!!
Alembics now work perfectly in Unreal!
I'd say you just saved us from some nasty workarounds!


Many many thanks, Tyson!
Very much appreciated!

[tyFlow]

Great!