Groom cache creates ghosting when using the movie render queue in4.27

When my Groom cache uses the movie rendering queue and the anti-aliasing option is turned on, my hair produce ghosting during movement, looking like the contents of the previous and the next frames are rendered. I have turned off motion blurring. And When I turn off anti-aliasing, the rendering results are correct. How can I avoid this problem.


Hey did you ever sort this out? This exact problem is driving me crazy right now.

I found that using the console variable r.OneFrameThreadLag 0 to turn off the render delay after one frame alleviated the problem but it still sometimes caused problems

The method I am using now is to manually tick the cache time. For example, if I need to render a video of 25 frames, I set the frame rate to 75 frames, sample all the hair animations of the 2nd frame at 1-3 frames, sample the 5th frame at 4-6 frames, and set the interval of 3 frames in the movie rendering queue.

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Thank you for your reply, but I’m not following you, apologies! Basically you render out 3x as many frames as you need and discard 2 frames per good frame?

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!
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

My render settings were all sampling once, so I concluded that the groom cache was producing an error when the render was loading. But unfortunately I didn’t find a solution to the problem.

Thank you for your reply, but I think yours is only enough to alleviate the ghosting, he is still there, but it is not obvious!

Thanks for posting this! I am experiencing the same problem. In my case, it’s using temporal sampling that is causing the issue, but I haven’t figured out a successful work-around. This definitely needs to be fixed!

This is the general process of my method. I found the method of manual tick from the cpp method, which seems not to be in the blueprint

Thank you for your reply, but I don’t know how you customized the events and functions.
Hope to get your answer!
I also wish Lao Tie a happy new year in advance!
It is convenient to add my Q: 919611812.