Moving a bone via blueprint

Development Character & Animation
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1

I’ve setup a demo of some systems for a game, where you play as a floppy octopus and you can attach to things.

You can see it in action here!

To get around some very strange behavior when creating physics constraints dynamically, I have to move the object I’m attaching to in the frame of the attachment, and then back again once the attachment is done (in the same frame).

Is there a way to do this with the physics asset attached to a bone? I can’t find any clear way to do that with Skeletal Controls … I will continue to dig through it, but if anyone could point me in the right direction I’d really appreciate it!

2

Still very stuck on this. Ran through a few more animation blueprint tutorials and the system makes a fair amount of sense.

Some limiting factors I’ve found include not being able to specify which bone I want to Modify (Transform), and not being able to set a destination for the bone I want to move dynamically. Anyone have any idea how to tackle these problems?

3

I’m still running into trouble with this. More generally, what is the best way to move a simulating skeletal mesh?

If I disable collision and physics, then move a skeletal mesh, it doesn’t seem to do anything. It seems like the blueprint commands that normally can teleport or set the location of an actor or component do not work with skeletal meshes that have their physics assets simulating.

4

How has this not been answered? I have also asked similar questions in other places, with not a single response.

5

Yeah I’m not too sure. Definitely blocking me from making significant progress right now. I’m still trying to figure out a workaround or a solution. Not looking too promising.

6

In 4.4.3 I’m able to use line trace to discern which bone I’m hitting, so that’s cool.

Now if I could just move that bone so I could attach the constraint properly. Anyone have any insight on any of this?

7

Hi Brian,

A PoseableMesh component will allow you to get a reference to all of the bones via blueprint. However it currently doesn’t support animations and physics being applied to it.

8

Cool I’ll check that out as a possibility.

Is there any way to move a bone or its physics asset through blueprint?

9

Ah, that’s great info. I will test out sockets and see if they work any better. Can I create / destroy them dynamically?

10

Using the poseable mesh will allow you to move the bones, however you won’t be able to use a PHaT asset with it. Looking at your Octopus game (which seems to rely heavily on this) I think the way to go would be with a custom animation.

Now for moving the asset; instead of creating a physics constraint you could try attaching the objects using sockets. But once again, it may not give you the effect you want because attaching objects to sockets will look much more rigid than what is currently in your game.

11

You can’t create and destroy them during run-time, but you can have them attached to the model and then attach/detach object to them dynamically.

12

Oh ok, I see. Is it possible to attach one socket to another across two skeletal meshes?

13

You must attach an actor directly to a socket. Here is another question about this and some documentation.

https://docs.unrealengine.com/latest/INT/Engine/Content/Types/SkeletalMeshes/Sockets/index.html