Find your lens Nodal Point easily for better Virtual Production results! 

Glad it was helpful!

I am waiting for my "other tracking system" to arrive, I will do the tutorial as soon as it does! In the meantime, this might be helpful ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-a-bkK5apunc.html it shows how to hook up the calibrator to an optitrack system. The same process can be used with any system where you can track the camera and a calibration board at the same time. ie: you need to attach a tracker to the calibration board. In this video he has some mocap marker balls attached to the back of his board. The first part where he calibrates the lens distortion is the same as my tutorial, the end, where he sets up and uses the nodal point calibrator, is what's different.

The VIVE calibration in UE already works, there is a video about it on the channel here ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-H5t2BwUGqkI.html to use it for other kinds of tracking you need to have the ability to track another object (besides the camera) like a checkerboard or aruco tag. Some systems like an Optitrack can do this. I'm working on a video to show how to set this up. I'm also trying to find a setup that will let you use the UE system to get your nodal offset without needing any hardware, it kind of works but right now is not reliable enough to publish. Still working on it.

Hi, unfortunately I don't have an antilatency system to review, sorry.

As shown in the tutorial, the offset is the measurement from the nodal point of the lens up to the tracking center of the tracker itself. For the vive puck this is easy because the tracking center is at the tripod screw. For vive controllers, this is harder because the tracking center of them is not marked. The best bet may be to open up the model of the vive controller in unreal, move it to 0,0,0 and create a sphere or cube also at 0,0,0. This should give you a good idea where the center of the controller is. As near as I can tell it's in the center of the handle just forward of the front most button. When you have the measurement, you need to add it to the tracker position you are getting in through livelink. This will put the unreal camera in the same place, relative to the tracker, as your real world camera rig. This can be done by adding a transform in livelink. Another way (which is more visual) is to create an actor that represents the tracker and has the livelink component, then "attach" the unreal camera to this and put the offset in the transform of the camera.

Yes, there are many solutions for getting tracker offset, unreal has one built in but straight out of the box it is only setup for VIVE. So this is an easy option for finding the nodal point of the lens that doesn't require hardware/software

You mean the camera can't be removed from the crane? That does make it harder. Most of the "automatic" methods for calibrating nodal point require you to be able to track both the camera and one other object. If you are using a vive or something like an optitrack or vicon this is fairly easy to setup but most other tracking systems only track the camera. I have heard of someone having success with the latest unreal using only the camera tracker but I don't have a good description of the method that I have been able to try. As soon as I get it, I'll try to make a tutorial. Is the problem that you can't take the camera off the crane to calibrate it? Let me know.

@@GregCorson Thanks for answering me. Yes, I can take the camera out of the crane. I am using a Vive and UE 5.0.3. It had not been clear to me if the calibration that you show in the video was exclusively for working on a tripod. So, technically I can do the calibration on a tripod and then put the camera on the crane, and everything would work correctly?

If you are using VIVE, you can use the vive nodal offset method from here ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-H5t2BwUGqkI.htmlsi=jhOsZFj0yZUG6Fq9 this is for 4.27 but the procedure has not changed. This requires a second vive tracker to use as a reference while you are calibrating and figures the nodal point and the offset to the tracker as well. Regardless what method you use, as long as you don't change where the tracker is mounted on the camera, you can put the camera on a tripod, crane or use handheld, no need to recalibrate. It's worth mentioning that there are actually two things you need to know, the nodal point of your lens and the offset from that point to where your tracker is mounted. The VIVE method figures both of those for you. If you use one of the manual methods you need to measure both yourself. It is good to know the actual nodal point on the lens. If later on you need to mount your tracker in a different place you can just remeasure the offset from the nodal point to the tracker instead of completely redoing everything. The other thing the nodal point can move when you zoom or focus, even on a non-zoom lens, sometimes it changes when refocused. You can test for this by measuring the nodal point at several different lens settings.

Regardless of whether you are using LED or not, you still want a correct nodal offset for your tracker. The image on the LED wall is being rendered for the position of your tracker. Without a nodal offset the camera position being rendered on the LED wall won't exactly match the nodal point of your real lens, so there could be misalignment. I have not done any LED wall work, but I think the offsets are not quite as critical as for greenscreen, but I could be wrong about that. Best to get a proper offset if you can.

@@GregCorson cheers Greg - much appreciated. And yes I think depending on what’s being shot, I can get away with much less calibration. Unreals lens calibration has nodal offset in it as a last stage in the process so will follow that too

You should be able to use this with any camera and any lens. Just be aware that if you change the zoom setting or focus the nodal point may move. If your lens has the electric zoom type, you might have trouble setting the exact focal length you want to calibrate. Start by calibrating it zoomed all the way in or out. If you want to shoot with the zoom in a middle setting, you may have trouble getting it set to exactly that spot every time, unless your camera has some kind of display of the current zoom focal length

@@GregCorson Thank you. I will all the time stick with the Full zoomout option. And do not plan to change it ever.. Thank you.

@@GregCorson One thing I dont get is: As I set the nodal point. What is the purpose of measuring the Up red line and back to the center pivot of the tracker. What will I use it for.?

When you are combining video from your camera with CG from unreal, you want the real and virtual cameras to be in exactly the same place. Otherwise the two will not stay lined up when they move and peoples feet may appear to slide when the camera moves. The offset from the nodal point back to the tracker is used to fix this. Unreal is getting the position of the tracker, so without the offset my unreal camera would be positioned above and behind my real one. So in unreal you apply the offset to the tracker, this locates your virtual camera in the same place as the real one.

@@GregCorson Sooo clear :-) Thanks a millionn

I'm not sure exactly what the problem is from your description. You mention BlackMagicMediaOutput but if you are trying to bring video INTO Unreal you want Black Magic input, right? There is a lot of information on BlackMagic setup in the link below, if that doesn't help please feel free to write again with more description of the problem and I'll try to help. docs.unrealengine.com/4.26/en-US/WorkingWithMedia/ProVideoIO/