I wonder how to put blendshapes for Jiggle Breast without bone.

Hi, Everyone!

I’m Nick. I’m Indie game developer.

I wonder how to make this kind of jiggle movement. (breast)

This is not morph target animation.
I know it is BlendShapes, how do i put blendshapes without morph target animation in breast?
Chain? Spring target? Please let me know any tutorial or guide.

Are you sure its morph targets? Have you asked him? Im not entirely sure if its blendshapes.
Ive made a similar jiggle system with bones, but I have to say, this looks really good. It might very well be some clever network of morph targets.
You should ask the guy how he did it, then its easy to transfer that knowledge to UE4.

There’s something very off-putting about that though…like it feels, excessive. Borderline Dead or Alive: BV levels of jiggle there.

Yes, it’s way too much.
That being said, there are two separate concepts here:

  1. How to deform the mesh
  2. How to decide how much to deform the mesh

The three possible answers to 1) are “morph targets” (which is the same technology as “blend shapes”) and “bone/skinning” and “procedural geometry” (which is a bit like blend shapes/morph targets, but still not.)
The two possible answers to 2) are “kinematically (animation) driven” and “physically (procedurally) driven.”

It’s pretty clear in the animation shown that it’s physically driven – stepping off that ledge causes the body to accelerate but the boobs not to.
If I were to guess, I’d say they used procedural animation of the vertices, based on the physics simulation – set up a spring system along each edge in the mesh, with some volume-conservation constraint, and run that simulation based on main body movement for each frame.
This could possibly even be done on the GPU.

Actually those boobs are soft body physical objects.

I think, it is based on the physics simulation too, how do i make this with many blendshapes on breast? spring system??

My guess that’s just a simple spring controller.

Add a bone to the rig for left and right breast and in the Anim Graph of the animation bp you are using add a Spring Controller to the animation migration path.

You will need two for left and right but once in place just target the bone you want to add a physics based spring, play around with the damping, and your done.

Frankie has a point there, I made this with spring controllers, theyre kinda cool, but still very limited and buggy… this was the state from a few months ago:unreal engine 4 - character controller update - YouTube
But I want to explore the features of the animDynamics node in the future as I think that can be also quite useful - I hope.

To fake this:
A single spring bone can work, although you’d likely want something for the in/out (“push”) direction too. That could perhaps be a spring system that drives a push/pull morph channel.
So, spring-bone for up/down/side, and a morph channel for pull/push, and two separate springs (one for the bone, one for the morph.)

Yeah that would work too, I do a thing where I get the length of the main breast bone, and drive a secondary scale to do volume preserve on pull/push.

The guy is using blendshapes, he says so in a comment on one of his other videos. (I would link to it, but the video is NSFW because he has the female character fully textured)

Quoting from his comment: