Physics Blend Weight causing jitter

Development World Creation
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1

I’m having troubles with using the Physics Blend Weight functionality.

When blending between physics and animation, there is a lot of jitter between the two.

How to reproduce

Open the map PhysicsAnimation in the content examples. Slide the Physics Blend Weight slider to 0.5

What happens

The limbs with physics applied jump around erratically (they have jitter)

What’s expected

The limbs should blend between physics and the animation smoothly.

Here’s the documentation on the map and subsequent feature I am referring to:

Hope anyone can shed any light on why this might be.

Best,

Minxies

2

Really hope someone can throw me a bone with this.

I’m really at a loss with it.

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3

I came here hoping to find an answer to this, did you figure it out yet ?

4

I also stumbled on this on engine & content examples version 4.11 (binary release). It definitely seems like a bug in the blending system. Epic, is someone already looking at this?

The issue becomes even more pronounced by setting the active animation sequence of the characters to “Idle”. (Select the character → select the SkeletalMesh1 component → set “Anim to Play” to “Idle”)

Initially, the characters stand almost still. Moving the blend weight slider even slightly away from 0.0 immediately introduces a steady “jitter” cycle: all affected bones seem to alter between falling freely and snapping back toward an apparently correctly blended pose. On my computer, this cycle runs at around 2-3 times per second.

5

For others who find this question, the discussion seems to continue here: Full ragdoll blending + stability - Character & Animation - Unreal Engine Forums

6

Same issue. I’m stumped.

7

This issue can be resolved by using the new PhysicsAnim UActorComponent.

You might also want to look at some of the animation solutions in the AnimGraph.

8

In my case the issue was resolved by turning off ‘bEnableUpdateRateOptimizations’ on the skeletalmeshcomponent. Apparently this optimization interferes with the physics blending, even when the camera is very close to the mesh.

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