ARFX Camera Components

Section 10. ARFX Camera Components

An important aspect of all ARFX Cameras and Virtual Production in general, is the Component list. Found within the Details panel when you select any actor, the component list of any given actor in Unreal Engine contains everything that makes up the actor you see represented in the Viewport. Be it a static mesh, light, or even our cameras, everything is derived from this list.

1. Navigate to the Details panel for the newly added ARwallCameraActor. If this panel is not active, please enable it by going to the Windows menu and selecting Details.

2. Once the panel is active, proceed to select the ARwallCameraActor within the Outliner.

3. You can do this by navigating to the Details panel and clicking the big green button ‘+Add Component’ in UE4 or the ‘+Add’ in UE5 dropdown.

4. Type in ARwall, select the ARwall, and choose your respective tracking component. The ARwallCameraActor object should appear in the World Outliner window.

Important

By default, the component list in the details panel is really small. You can expand the list by mousing over its bottom edge until your mouse turns into an expansion icon for you to then size it to your needs.

ARFX Camera’s component list. There is a lot here but there is not much to actually do.

Important

This cannot be stressed enough: Do not edit any of the default components of the ARFX Camera unless you know what you are doing.

Every component in the default list serves a purpose when it comes to orientation and tracking. If you do accidentally change these components, an easy fix is to simply delete the camera and place a fresh one in its place. Since settings like screen dimensions and tracker serials are saved and shared across all actors regardless of scene you will not be losing much in doing so.

Section 10.1 The Single Exception – Offset Component

The Offset Component, nested above the Camera Component, is generally never used, but it does serve a purpose. Depending on the physical setup of your tracking device and how it is attached to your physical camera, the position of said tracker may be far away from where the camera’s sensor is located. Sometimes that difference in location can be significant enough to cause oddities such as height extremes when tilting up or down or simply that the background is simply off to the left or right.

The fix for that is this offset component. You must measure the distance between the tracker’s origin point and the camera sensor’s center precisely in centimeters then translate those values into the components’ position values.

The positions found here for the offset component determine tracker offset. Note the orientation. DO NOT CHANGE THIS.

But which values go into which entry? The following image can help you figure this out:

The orientation may seem weird if you know Unreal or typical Euler orientations, but there are reasons for this.

Let us try a real-world example. On our camera we have our VIVE Tracker almost aligned with the sensor, but not perfectly. Measuring it we found it to be 16 cm above and 1 cm behind the sensor.

We find that most camera sensor’s depth is often represented by the focus puller hook. So if you can, use this to measure how far back or forward your tracker is.

With these values, we can input them into our offset like so:

Again, do NOT change the rotation, just the position!

The camera in the Viewport should shift slightly to represent where the sensor actually is and you should be done! You can test this by trying to do shots where the camera is aligned with a straight wall and see if you can see down its length on the camera’s viewfinder.

Important

Each tracker’s center point is different and most manufacturers do not detail this important information. Generally it’s safe to assume it’s at the center of the device or sensor receptor (on Vive Trackers it is the mounting point at the bottom of the device).

Section 10.2 List of ARwall Companion Components

The full list of available components used in ARFX Cameras and their Lens Emulation variants.

By clicking the green + button above the component list you can add the above list of components. The most important in the list are the various kinds of tracking components, which send tracking data to our ARFX Camera and drive our virtual backdrop’s position. The lens components are for our LensEmulation variants, which can take in focus data and emulate that effect on our ARFX Cameras.

Section 10.3 SteamVR Tracking Component

Our old faithful. The SteamVR component leverages OpenVR and Valve’s SteamVR software to obtain tracking information wired or wirelessly. It is technically device agnostic, meaning you can use the recommended Vive trackers or VR controllers such as that from the Valve Index. Please check out Track_SteamVR section for more information.

Section 10.4 Universal Tracking Component

This component utilizes other actors in the scene to derive its tracking data from instead of directly from the source. In this way, you can use any tracking setup you please without having to jostle with the likes of Live Link trying to control the ARFX camera as though it were a normal Cine Camera. This component can, therefore, support any and all tracking styles, whether it be from Live Link or proprietary tracking components and camera setups. Please check out the Track_Universal Section for more information.

Section 10.5 Free-D Tracking Component

Our own implementation of the Free-D tracking standard. We do generally ask that users use Live Link and the Universal Tracking Component instead of this, but that does not mean you should not. It is capable of pulling Free-D tracking data as well as lens data if your tracking hardware supports it. Please check out the Track_FreeD Section for more information.                  

Section 10.6 Manual Tracking Component

A tracking component geared more towards developers or Blueprint] savvy users. The functionality of this component can be customized to fit whatever tracking device that is not supported by any of the other standards. Please check out the Track_Manual Section for more information.

Section 10.7 Cine Cam Lens Component

Specifically for our LensEmulation supported ARFX cameras, this component is akin to the Universal Tracking Component in that it pulls its tracking data from any referenced Cine Camera with lens data being fed to it. Depending on how the data is being pulled, you may be able to further customize the data however way you wish. For more information, please check out Track_LensCineCam.

Section 10.8 Canon Lens Component

An in-house implementation of Canon’s direct lens data polling. Done in partnership with Canon, this particular component works only with the Compact-Servo 18-80mm as of now. The data is 1:1 with the lens itself. No guesstimation or interpolation done. For more information, please check out Track_LensCanon