# Groom cache stuttering / miss match during render

**URL:** <https://forums.unrealengine.com/t/groom-cache-stuttering-miss-match-during-render/653552>\
**Category:** Rendering\
**Tags:** unreal-engine, UE5-0, Rendering, UE4-27\
**Created:** [September 21, 2022, 6:12pm UTC](https://forums.unrealengine.com/t/groom-cache-stuttering-miss-match-during-render/653552 "2022-09-21T18:12:22Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Andrej730](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/andrej730/32/1194692_2.png) [@Andrej730](https://forums.unrealengine.com/u/Andrej730)\
**Post date:** [September 21, 2022, 6:12pm UTC](https://forums.unrealengine.com/t/groom-cache-stuttering-miss-match-during-render/653552/1 "2022-09-21T18:12:22Z")

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I’ve met the problem during the render of groom cache both in UE4.27 and UE5.0 - groom looked stuttering when moved, like it was missmatching character geometry.  
What I’ve noticed investigating this that’s when viewing groom in viewport I noticed that it’s kind of takes a couple secs for groom to set correctly and I was looking for a way to give render that time during render to kind of warm up each frame.  
The solution was to add more temporal samples (32 samples worked) to kind of warm up each render frame.

Issue (aa enabled, 1 temporal 1 spatial sample):

Solved (32 temporal samples):

Rendering process (you can see that first samples are kind of stattering but number of samples helps):

Reported issue to unreal, hopefully they’ll answer. (Case # 00479141 (@21.09.22): Groom cache stuttering / miss match during render)

List of similar issues I’ve found looking for solution (it’s possible that my solution could solve some of them):

> [@Groom cache Render issue](https://forums.unrealengine.com/t/groom-cache-render-issue/490288):
>
> Hi there I try again import groom cache in UE 4.27.1 But continuously miss match. I’m not use geometry cache binding groom cache. The maya data is correct but result rendered by engine is not correct. Should I change the render option in Engine? [Test Groom Cache 3][1] [1]:

> [@Movie render queue render groom hair bag](https://forums.unrealengine.com/t/movie-render-queue-render-groom-hair-bag/530272):
>
> the model moves in front of the feathers. how can i solve this problem

[https://www.reddit.com/r/unrealengine/comments/tr53ga/can\_anyone\_tell\_me\_why\_my\_groom\_cache\_lingers\_for/](https://www.reddit.com/r/unrealengine/comments/tr53ga/can_anyone_tell_me_why_my_groom_cache_lingers_for/)  
[https://www.reddit.com/r/unrealengine/comments/sj3qlb/groom\_cache\_issue/](https://www.reddit.com/r/unrealengine/comments/sj3qlb/groom_cache_issue/)

> [@我使用 Movie render queque渲染groom abc缓存毛发时抖动](https://forums.unrealengine.com/t/movie-render-queque-groom-abc/490818):
>
> 1.我使用xgen制作了groom的缓存 ,使用alembic导出的缓存序列。 2.再最终渲染输出时使用movie render queue，并使用Anti-aliasing来抗锯齿，但是只要设置了Temporal Sample Count大于1就会出现错误。 3.movie render queue 在渲染过程中，我发现Sub Sample 的第一次发生位置错误。 [352004-v011.gif] 4.最终导致图像出现虚影。

> [@Groom cache creates ghosting when using the movie render queue in4.27](https://forums.unrealengine.com/t/groom-cache-creates-ghosting-when-using-the-movie-render-queue-in4-27/272138):
>
> Hello! I also encountered this problem when rendering the groom cache using the Movie render queue. And I found the cause of the problem, but unfortunately I didn’t find a solution! [v065] in the video Red: there is no jitter in the abc cache of poly Green: The hair asset is imported into UE, and there is no jitter in the animation of the Key in the sequence. Only the yellow one is that the groom cache is shaking y render settings were all sampling once, so I concluded that the g…