Can you attach hair strands to blendshapes?

[userresu]

Hey!

Im using ue4.25 and trying to figure out a proper workflow for human face animation with hair.

My problem is that I have a rigged face with facial expressions (blendshapes) and I cant figure out how to move the eyebrows and beard when I animate the blendshape values.

I get that i can bind the groom to the skeletal mesh but i dont understand how the binding algorithm works. Is it checking every guide root position and finds the nearest polygon and checks which bone is it skinned to and that is the one which moves the fur? So should i use small bones to make a proper eyebrow movement?

thanks for the help

cheers

[userresu]

It turned out that the problem was that I scaled the groom component, so when the shape deformed, the transform got multiplied with 10 so the strands were moving all over the place.

So, conclusion: No problems with skinned and/or blendshaped objects with grooming components. It looks like the groom follows the closest surface.

[RyiGarry]

Hey, was just wondering if you could share how you achieved this? I’m trying to attach a groom to a mesh with blendshapes, but it doesn’t seem to react when I run the blendshapes through.

[anonymous_user_5808d33d]

I also engadge this problem, my character with morphtargets facial animation, but I don’t know how to drive beard groom when character open mouth by morphtargets, in maya groom base could warp the blendshape, but I don’t know if UE got the same proposed, or I could only binding the groom in a rigging skeletal mesh. But I want to make a ARface character, iphone just work on morphtargets.

[userresu]

Hey!

So I assume you are using 4.26:

1. You need to import the skeletal mesh with your morph targets and the groom in alembic.
2. Drag and drop them in the scene to check if the scale is the same
3. In the scene on the skeletal mesh’s detail panel add a groom component.
4. On the groom component set your groom asset
5. In the content browser right click on your groom asset and create a binding asset (this is the stuff which attaches the groom to the skin)
6. Select your target skeletal mesh with your morphs on the pop up panel (check the output log for errors if its not working)
7. In the scene on your skeletal mesh’s groom component set the binding asset.

That’s it basically. Let me know if it worked out.

[userresu]

It works fine with blendshapes if you create a bind asset in 4.26. I am using it with an iPhone as well. Check my answer below

[RyiGarry]

Hey, many thanks - I got it working the other day in 4.25 but it kept crashing when I tried to attach the groom to the mesh. Seems to be working fine in 4.26 now - presume cause the groom importer is out of beta.

[sergiosergio]

Hey, I’m using UE4.26, and followed this exact steps, the hair follos the skeletal mesh’s movement caused by the bones, but it ignores the blend shapes

[DrHippoDev]

For anyone who was stuck on this as I was - I eventually figured it out. In my case I had to ensure support compute skin cache was enabled in project settings as well as setting default skin cache behavior to inclusive.

[falconking1111]

I did everything that you guys recommended here but still the groom will not attach. The moment I load an animation it just hangs in the air. Is there a way to this using a blueprint ? this is the only thing holding my project from completion !

[StereoBurst]

Dude, you are a life saver! thank you!

[FaradayPrime]

So i don’t know if this just helped me, but try to play with the Matching Section when creating the groom binding, for me, setting Matching Section to 1, worked

but i also followed all previous advice, DrHippoDev’s tip to “ensure support compute skin cache was enabled in project settings as well as setting default skin cache behavior to inclusive”
and Userresu’s 7 step guide.

these combined, plus setting Matching Section to 1, worked for me

in my case, i had a source skeletal mesh, and a targeted mesh for the binding.
maybe that is why Matching Section needed to be set to 1 for me