Ghost effect while camera moves

Studio Operators Content Creation Composer

 

Playing with a video - while moving the camera - I noticed on a ghost effect next to the presenter shoulder.

Any idea whats the cause for that?

Link for the video
https://drive.google.com/file/d/1lXZIaqO69TkuiZONLxeinKHIeSvGo6ij/view?usp=sharing
Thanks for any idea...

   videobox

 
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TwentyStudios
8/16/2022 8:57:10 PM
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Turning off Write to depth might help with the ghosting, but the bigger issue is your extreme stuttering when you move the camera. It shouldn’t look like this. Have you matched the project frame rate with the output settings in Aximmetry and the rest of your signal chain?

 
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videobox
8/17/2022 7:31:23 AM
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Thank you TwentyStudios,

Can you please let me know where is the "Write to Depth" ? tried to search for it - couldn't find it.

I disable "Allow Virtuals" - and it seems that it made the ghost gone.  (dont know why? )

Thanks again...


 
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TwentyStudios
8/17/2022 8:40:15 PM
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It’s in the Billboards panel.

 
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hasanfurkan
8/23/2022 2:02:48 PM
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Setting up objects in front of the billboard

If you place objects in front of the billboard, you have to take some steps to avoid visual artifacts. The reason is that Unreal uses Temporal Anti-Aliasing (TAA) to make the edges of objects look smooth.
The original TAA algorithm makes the billboard very blurry so we modified it to fix this problem. This modified version needs to know about objects in front of the billboard to correctly handle edges and translucency.
To provide this information, you have to mark all objects that can occlude the billboard with a special stencil value:

If the object is opaque:

  • Select the object.
  • In the Detail window, go to the Rendering section.
  • Enable Render CustomDepth Pass.
  • Set CustomDepth Stencil Value to 16.

Note: Not doing this results in aliasing and jittering at the edge of the object.

If the object is translucent:

  • Select the object.
  • In the Detail window, go to the Rendering section.
  • Enable Render CustomDepth Pass.
  • Set CustomDepth Stencil Value to 32.
  • Go to the material editor by double clicking the translucent material in the Content Browser.
  • In the Details window, enable Translucency / Allow Custom Depth Writes.
  • Set Material / Opacity Mask Clip Value to 0.

Note: Not doing this results in aliasing and jittering at the edge of the object and in front of the billboard.

 
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videobox
9/20/2022 5:36:38 PM
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Hi Hasan,
Thank you for the detailed reply.
Looking at Unreal - cant find the Render CustomDepth Pass.
And 
Set CustomDepth Stencil Value to 16.
attach a link for an image 
https://justpaste.it/9lkhy

And here https://justpaste.it/8grva
Tried to choose the objects - not sure I'm doing it correctly.

The video of the green is in high quality - but somehow in Aximmetry the quality isn't %100 

Thank you again for your help.




 
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hasanfurkan
9/20/2022 5:55:01 PM
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You have to click the objects, then you will find them in the details section in the rendering section.


 
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videobox
9/29/2022 9:06:46 AM
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Thank you so much hasanfurkan

I tried that and I didnt see a major difference.

The main point is that the quality of the video in green screen is degraded when showing up in Aximmetry - donnow whats the reason causing it.


 
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Eifert@Aximmetry
10/4/2022 2:12:10 PM
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Hi Videobox,

Can you show a video of your problem, with the degraded quality?
I think your problem might not be related to "Setting up objects in front of the billboard".

Also, don't forget to do these settings to your project in Unreal: https://aximmetry.com/learn/tutorials/for-aximmetry-de-users/how-to-install-and-work-with-the-unreal-engine-based-de-edition/#how-to-create-your-own-projects

Warmest regards,

 
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videobox
10/11/2022 6:21:31 PM
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@Eifert  

How can I send you a private link for Google drive?

What can be else:  "I think your problem might not be related to "Setting up objects in front of the billboard". 
Could be  in the UnrealProject configration?

Thank you,


 
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Eifert@Aximmetry
10/12/2022 7:58:41 AM
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Hi Videobox,

Usually, people share videos here with public google drive links or just upload them as unlisted videos on youtube.

If you have some content in your video that you don't want to share with the public, you are free to send the link to your video to sales@aximmetry.com and refer to this forum post in the mail.

Warmest regards,

 
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Eifert@Aximmetry
10/13/2022 11:19:24 AM
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Hi Videobox,

Thank you for sending it through the mail.

The ghost effect is caused by these trees outside of the building:

Their material reacts badly with the TAA anti-aliasing method. This is a common problem with some foliage materials. And so this is independent of Aximmetry's Billboard. You can move any objects in front of those trees and you will see the same ghosting effect.

There are several problems with your video that are not related to the ghosting effect. But they probably cause your perceived degraded quality:
First, the keying is wrong, please read our documentation about keying carefully: https://aximmetry.com/learn/tutorials/for-studio-operators/using-the-advanced-b-keyer/ Low Cut should never be higher than High Cut.

The Inverse Tonemap is turned off which causes the darkening the billboard:

More on inverse tone mapping here: https://aximmetry.com/learn/tutorials/for-aximmetry-de-users/how-to-install-and-work-with-the-unreal-engine-based-de-edition/#aximmetry-virtual-camera-details 

The final video you recorded was lagging. Your computer probably didn't have enough resources to render in real-time. However, it looks like to me you might want to record your video in post-production and not in real-time. In that case, you can use a Video Recorder module instead of the Record_* compound. And set it to render in fixed frame rate:

When doing fixed frame rate rendering, the recorder will wait for each frame to be rendered so there will be no missing frames that cause the lag.
You can even set the resolution as high as you want in this case and do a double sampling pixels for example.

Warmest regards,


 
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videobox
10/16/2022 1:05:13 PM
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Hi Eifert,

Thank you so much for the detailed explanation.
I went through all that you wrote me: 
 Inverse Tonemap
How to do the keying properly (went through it from A-Z  and update with some online tutorials)

Trying to improve it and will update.
One more thing is the export from Premiere MXF to h264. ( is there any other format suggestion for the export?)
I probably shrink the video for a lower bitrate that also influence on the quality in addition to all the other workflow tunings. 

The process I worked here was to shoot first on a green screen than to edit it in Aximmetry.
The recorder module looks a bit different from what you had here. (or I might import the wrong module).


Thank you again,  will update after doing more testing with the different options.


 
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Eifert@Aximmetry
10/17/2022 9:06:37 AM
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Hi Videobox,

In your screenshot, you have a compound named Video_Recorder, but I was referring to a module named Video Recorder.
You can add modules by right-clicking on the Flow Editor and selecting Insert Module:

However, the compound Video_Recorder has a Video Recorder module inside it, so the module and the compound in this case are pretty much the same. It might be even more practical for you to use the compound instead of the module.

What format you want to use when exporting the final video, depends on your targeted medium (platform, software, streaming service...). For example, if you want to further edit the footage in different software then you might want to use DNxHD, DNxHR, or Cineform.

For recording the green screen footage for post-process, use very high-quality settings. The default settings in the Tracked camera are already like that:

This won't affect the bit rate of the final video.

Warmest regards,