How to calibrate the floor of real scene and the floor of the UE scene use tracked camera?

FAQ Camera Tracking Unreal

 

I use T265 calibration the lens and tracking system,How do I set the height of the tracking camera from floor

   bigdream

 
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kimminhtien9
9/6/2022 2:16:16 PM
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Yes you can, i use T265 just like you. I had a hard time calibrating the floor at first, but now it's much easier to jown. You can use the aruco marker module in Aximmetry to make floor calibration easier.

 
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bigdream
9/6/2022 2:27:01 PM
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@kimminhtien9 Sounds good.  Do you have any  tutorials about that?

 
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Deleted User
9/12/2022 6:23:08 AM
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Hello,

You can follow this tutorial. This playlist is also really helpful in case you prefer visual learning.

Best regards,


 
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davidrynes
9/12/2022 2:00:02 PM
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@kimminhtien9 Can you please show us how to use aruco marker module? Thanks!

 
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Eifert@Aximmetry
9/19/2022 12:55:57 PM
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Hi David,

You can find some more information about aruco here: https://my.aximmetry.com/post/64-software-based-real-time-object-tracking

Which part of the module do you want to know more or do you want to know how to make floor calibration easier with it?

Warmest regards,

 
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davidrynes
9/19/2022 5:39:34 PM
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Hi Eifert@Aximmetry!

In our new studio setup we have green desk so we can put there a virtual one. We have tracking system right now with HTC Vive Trackers (one si uprotated, but we will solve this). What we have hard times to solve is place billboard "realistically" in line with virtual desk so talents cant rest their hands on green desk, but in Aximmetry they will be on virtual one.
So we want to achieve something like this on images below.

Also two other questions. Can we use HTC trackers as some basic lens encoder for zooming? Can we modify SWITCH module to make more than 16?

Thanks,

with regards David!



 
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Eifert@Aximmetry
9/22/2022 3:29:52 PM
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Hi David,

You could use the HTC Vive controller or the trackers to get the table's location before shooting. They should give a better position than the aruco.

If you can, you should try it without using billboards:

This way the talent will be always over the table.


If you really want to use billboards, you will have to track the talent too or the talent shouldn't move after placing the billboard behind the table. And in general, you will have very limited options on setting a realistic shadow or reflections.

And when you place the billboard behind the table, just like where it is exactly in the real world, his hand will be cut off by the virtual table. However, you can easily circumvent this in Aximmetry. Turn off Allow Virtuals:

And disconnect B Mask, so that Aximmetry stops cutting the billboard with the overlapping objects in Unreal:

Also, you will probably need very accurate tracking with lens calibration included.
And feel free to send more information about how things are going.

I am guessing you are not using a fixed position camera (PTZ). In the case of PTZ, there are probably some tricks depending on your case, that makes even better composites.


I don't think there is a way to use HTC trackers as encoders for zoom or focus.


In this forum thread, you can read how to link modules to make a switch with more than 16 switches: https://my.aximmetry.com/post/2196-switch-with-more-than-16-value-pins

Warmest regards,



 
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davidrynes
9/22/2022 6:51:28 PM
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Thanks a lot Eifert@Aximmetry!

Right now our test setup looks something like image below. We are now without reflections, but gonna try those tips with virtuals etc., and keep you informed. Can you elaborate more on that how to get table location with vive tracker? We have two more trackers and two vive controllers which we dont use, so we can mess with them. Also one other question. Did someone manage to workaround TALLY lights on Blackmagic Studio Cameras with aximmetry? We can use ATEM which we have in our department, but if I'm not wrong, for that we will need multimachine so every single camera goes to computer and from that to ATEM and from ATEM to broadcast computer, am I right? 


 
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Eifert@Aximmetry
9/23/2022 2:35:42 PM
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Hi David,

You could put one tracker on the top of the table to get the surface position of the table. You can use the Camera Tracking module for this.
You can even easily record the current position coming from the Camera Tracking module by using the Capture Input option. After using the Capture Input and severing the connection to the pin, the Copy Transformation has the captured transformation filled out in the Pin Values panel:

I don't know of somebody controlling a Blackmagic camera's tally lights from Aximmetry.

Yes, you could use ATEM to switch between outputs of a multimachine setup. And it doesn't make much sense with one computer as you would have only one 1 final output. Or you could switch between the output and preview of that one machine. Possible preview configurations are discussed in this video at the 27:47 mark: https://aximmetry.com/learn/tutorials/for-studio-operators/setting-up-virtual-sets-with-vr-cameras/

Warmest regards,

 
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davidrynes
9/26/2022 9:57:53 PM
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Thanks Eifert!,

That looks like a reasonable way. Another Q. Right now we dont have lens encoders. Can I somehow manually change adjust depth of field for each CAM while in TrackedCAM? I know that in VCAM there is a shortcut for it, but in Tracked Cam it doesnt work and I saw that idea with scalar, but its global settings for all cams, but I need different values for each cam. Thanks!

 
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Eifert@Aximmetry
10/3/2022 10:15:08 AM
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Hi David,

Set Manual Lens On in the Input panels. And then you can manually set the focus (Depth of Field) in the Manual Focus:

You only need the idea with scalars when you want more direct/dynamic control of focus.
Also, in that case, you can use a Transmit Integer module to get the currently selected camera. And based on that you can switch between different focus values like this:

Warmest regards,

 
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Lardgemon
10/6/2022 1:39:23 AM
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Hi @Eifert,

I am interest in the above topic you and David are addressing. I use T265 for calibration and tracking system. How do I set the height of the tracking camera from floor using the Marker Detector module in Aximmetry?

I will appreciate any input...

 
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Eifert@Aximmetry
10/6/2022 2:56:47 PM
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Hi Lardgemon,

Somebody asked the same question recently, I answered in that post thread: https://my.aximmetry.com/post/2228-aruco-markers-to-position-my-tracked-cam

Warmest regards,