UE5 Lens Calibration Error after applying nodalpoint offset

Development Cinematics & Media Virtual Production
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1

Hi I’m using UE5 Lens file for camera calibration
lens distortion is calculated well but after calculating nodalpoint and apply it to my camera the camera is jumping like this

is there any help for this?

1 Like
2

do you have camera tracking active? it kind of looks like it’s in conflict with what was calculated, and where it might be tracked to?

and how accurate was your lens cal? did the returned values match your real set up? We’ve had some weird issues when we had an anomalous calibration.

3

thanks for your reply!
the calibration data was quite good, the reprojection error was about 0.1
and it worked well comparing to my checkerboard

i also thought it was about conflicting tracking data but even after disconnecting livelink data the issue is keep happening

4

what method are you using to calculate the nodal offset?

5

I’m using this method

With VIVE MARS

6

mmm, yes, we have not been able to get this particular workflow to work well in our testing yet. We also got weird behavior, but not quite the same as yours. We moved on to testing with Aruco markers on the LED wall, and found better results… unfortunately, i don’t have any other useful info towards resolving the issues in this one… sorry

7

okay! thanks for your reply!
it’s good to calibrate your distortion and nodalpoint before you using ArUco markers

8

i thought that ArUco was a method of nodal calibration it’s self…? the documentation does the lens cal first, and then a nodel using aruco… wouldn’t it just be recalculating and offsets if you did it a second time?

9

Hi,When I use the cheekboard to calibrate the lens and offset the nodes, I get a correct result.Then I used Aruco to calibrate the position of the LED walls.However, when I follow the steps of UE4.27 or UE5 document to apply, the location of Ndisplay is completely wrong.Do you have any idea? Thanks.

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as i know Aruco marker is for recentoring tracking origin i’m not sure about calculating nocalpoint with ArUco markers

11

can i see your result and project screenshot?

12

Sure,But I can’t show you the results right now.In short，when I place camera in ndisplay, I apply the calculation results. The final result is that NDISPLAY’s position coordinates in the map reach tens of thousands, or the angle has a huge deflection.Can I send you an email?

13

sure you can send(send me message i will give you my e mail) but i can not sure how to solve it
i successed camera calibration and ArUco marker with VIVE track 3.0 in UE4.27
but UE5 and latest 4.27 version is not working properly

14

yes, we had that as well – when applying the nodal offset, the camera would fly to some sort of origin point. It was a few months back now, so i don’t recall the particulars. Following for any resolution.

15

You reminded me，when I tested in UE4.27 at the end of last year, the results of using ARUCO to calibrate the origin were available.After we updated UE4.27.2 this year, the same method failed.

16

We have the same result，Now we are trying to calibrate ARUCO with our own compilation tool, but we are still in the learning stage.

17

Hello,

are the lens file unreal made to have zoom values (movement of the focal length)? If so how can I calibrate it, apparently all the documentation sets the distortion to a single zoom value.

Regards,

18

Hi I think this video might help you
as i know you should calibrate few focal length and save it tin lens file and distortion values will apply according to your livelink virtual subject value

if you have lens encoder it would be easy to tracking your lens data realtime