# Skeletal Mesh Physics Assets Working Incorrectly **URL:** \ **Category:** World Creation\ **Tags:** UE4-17, UE4-16, unreal-engine, Physics, question\ **Created:** [August 7, 2017, 4:45pm UTC](https://forums.unrealengine.com/t/skeletal-mesh-physics-assets-working-incorrectly/401279 "2017-08-07T16:45:23Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Efrye](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/efrye/32/1194658_2.png) [@Efrye](https://forums.unrealengine.com/u/Efrye)\ **Post date:** [August 7, 2017, 4:45pm UTC](https://forums.unrealengine.com/t/skeletal-mesh-physics-assets-working-incorrectly/401279/1 "2017-08-07T16:45:23Z")
Since UE 4.16, skeletal mesh physics assets appear to behave incorrectly during world movement. Whether it’s ponytails, jiggle bones or arms and legs, they all jerk around uncontrollably when attached to a moving character, regardless of the physics settings I choose. Enabling substepping in the project settings still prevents bone chains to stretch and separate, but no longer leads to smooth physics behavior. There was a similar issue in UE 4.8 that was fixed in 4.9 [(referred to in this thread)][1]. Maybe this problem is related? I created a sample project with a ponytail on the default third person character. It’s working perfectly in 4.15 and breaks after converting to 4.16 or 4.17. [(Download 90MB)][2] I would greatly appreciate if you could look into this! ![](https://d3kjluh73b9h9o.cloudfront.net/original/4X/e/0/1/e013cbcf547278ce019805f06c2a52c739bf5b27.gif) ---
**Author:** ![TJ\_V](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/tj_v/32/1008648_2.png) [@TJ\_V](https://forums.unrealengine.com/u/TJ_V)\ **Post date:** [August 8, 2017, 3:16pm UTC](https://forums.unrealengine.com/t/skeletal-mesh-physics-assets-working-incorrectly/401279/2 "2017-08-08T15:16:38Z")
Hi Efrye, Thank you for the report and the test projects. I was able to reproduce this behavior so I’ve created [JIRA UE-48150](https://issues.unrealengine.com/issue/UE-48150). Our developers will be investigating further. Follow that link to monitor the status of the report. -TJ ---
**Author:** ![Efrye](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/efrye/32/1194658_2.png) [@Efrye](https://forums.unrealengine.com/u/Efrye)\ **Post date:** [August 8, 2017, 3:32pm UTC](https://forums.unrealengine.com/t/skeletal-mesh-physics-assets-working-incorrectly/401279/3 "2017-08-08T15:32:48Z")
Thank you! ---
**Author:** ![anonymous\_user\_cbe433ac](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_cbe433ac](https://forums.unrealengine.com/u/anonymous_user_cbe433ac)\ **Post date:** [August 29, 2017, 8:00pm UTC](https://forums.unrealengine.com/t/skeletal-mesh-physics-assets-working-incorrectly/401279/4 "2017-08-29T20:00:33Z")
TJ, This issue affects my project pretty hard, has this been committed in any branch yet? ---
**Author:** ![TJ\_V](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/tj_v/32/1008648_2.png) [@TJ\_V](https://forums.unrealengine.com/u/TJ_V)\ **Post date:** [August 30, 2017, 8:27pm UTC](https://forums.unrealengine.com/t/skeletal-mesh-physics-assets-working-incorrectly/401279/5 "2017-08-30T20:27:04Z")
Hey Derelict, The target version for the fix is 4.18, but that isn’t a guarantee it will make it into that version. It’s been fixed in the dev-stream internally but it hasn’t been merged into the Main branch yet. ---
**Author:** ![Micke879](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Micke879](https://forums.unrealengine.com/u/Micke879)\ **Post date:** [September 30, 2017, 1:47pm UTC](https://forums.unrealengine.com/t/skeletal-mesh-physics-assets-working-incorrectly/401279/6 "2017-09-30T13:47:08Z")
For anyone wondering: while waiting for the bug to be put into a patch, you can still use the experimental APEX Clothing Tool.