Is it possible to capture live camera video and unreal background separately ?

Content Creation Editions Composer Video Recording SDI Camera Tracking


i am using HTC vive to do track camera ,  to me it is difficult to do the focal length tracking , just thinking if possible to capture the live foreground and unreal background separately , so i can redo the comp in nuke or ae , i can rekey the green screen and do the defocus , or add other filter what i need . and to do this i need to re sync the fg and bg in post , timecode maybe needed .any suggestion ? or if Aximmetry support defocus function ?


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Hi Renjibo,

It's possible.

Firstly you have to make sure that Unreal does not render the talent. For that select the SCENE panel.
a) If you do not need the reflection nor shadow of the talent simply turn off Use Billboards.
If you need the reflection or shadow, leave Use Billboards on, but turn off Allow Virtuals.

Now you have to provide access to the raw camera input. For that you have to open up the TrackedCam_XXX compound.
Right-click it then

Then go to the INPUTS board and right-click INPUT 1

Here you'll find a module named INPUT.  Its Video pin outputs the raw image you need. Expose it to the right:

Name it e.g. Raw Input

Go one level up and repeat the exposion until you get an output on the TrackedCam_XXX module itself.

Now add two Video Recorders, one for the Raw Input and one for the virtual background.

Set up the output file and format parameters for both recorderds.
Important:  make sure that Frame Rate is set to Realtime for both.

To ensure the synchronized start of recorders use a common source of a trigger.

Timecode is automatically added to the output files if the format supports it.
By default it starts from zero when the recording is started.
Alternatively by turning on Use Master TC on both recorders you can use the continuously running internal time code of Aximmetry.

If you use an SDI input and you camera is capable of sending time code then you can use it as well.
For that turn on Timecode Master for your input.  This will override the internal Aximmetry timecode with the one coming from the camera.


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I have a similar situation and was trying the solution on 2021.2 but can't find the same nodes. Is this outdated?

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Hello Zoltan

I just tried to follow your instruction but can't see "go to source module" option in INPUT module.

Only can see that option in STUDIO, SCENE and LIGHT WRAP modules.

Is it limited in Community version?

Thanks in advance.


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I have figured this out bruce!

Unfortunatly haven't tested yet since I don't have access to the equipment atm.

This is also available with the mixed camera which is the one I will use in this explanaition. Everything is the same in the tracked camera compounds:

First open you mixed Camera Compound

Hit CTRL + F and search for TrackedCam > Right Click and "edit compound in place"

Search for "Input 1" > enter this compound

Search for "Line1" > Enter this compound

Search for "Input" > Now you can follow zoltans tutorial

If you want to use the Vcams it is the same process

I will try testing this week but untill then if anyone could answear my questions I would appreciate it.

So I am guessing this will record the camera inputs assigned to each Tracked/Vcam input module. Does it record without cuts when I switch cameras live?

This only records the 3D environment being outputed to the program (with cuts). What if I want to record each VCam/Tracked CAM movement and add the cuts in post?

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Hi all,

Yes, there has been some changes. The VirtualCam and TrackedCam compounds have been made more modular inside, meaning INPUT is inside another linked compound now.  It's called INPUT %N=1. You have to unlink it as well,  after that Go To will work as before.

Please note that in the release MixedCam will also go through the same changes, so AxiTry's solution won't work.  Therefore please do as I described above.

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I try the following procedure to record clear 3D background and work only without billboard. 
If I turn on the  billboard its not work. I use the billboard  a lot  and will be great to if have a possibility  to record clear Background to composite on After Effect ...

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@CharlieBG: If you use tracked camera with Billboards you must turn off Allow Virtuals, otherwise the video will be rendered through the Unreal pipeline and baked into the scene. With virtual cameras you just turn off Allow Virtuals.