Changing ARRI Camera Setting in Real-Time with UE4
ARRI CAP the back door to ARRI Camera Settings, allows VP developers to control on-set cameras from the VP system inside Unreal Engine.
When I spotted this post about how to change ARRI LUTS live in-camera during recording / streaming. I thought about how the ARRI CAP (Camera Access Protocol) may be your gateway to controlling the ARRI Alexa from any device.
When we drilled in a little deeper to see what I could find out about ARRI CAP and what else you could control remotely using the cameras API. The answer seems to be pretty much anything you can do in camera, at the on-camera menu you can do remotely using a long list of available call and set commands.
Integrating ARRI CAP API for Virtual Production Systems
If you shoot an optical layer of the actors on-set performance in-camera, in say a live composited virtual production you will have a virtual replica of the on-set camera in your engine, it’s called your virtual camera. The movement of the on-set camera is tracked using camera tracking technology and the camera operators performance is all captured and streamed to the virtual camera in the engine. The V-cam shoots the CG elements of the scene while the on-set optical camera shoots the real actors on set. These shots are then composited in real-time on the VP system.
It’s a challenge of virtual production, to calibrate the settings on both the optical cameras and the virtual in-engine cameras, especially in between takes and set-ups, and until we found this, impossible during takes. But with ARRI CAP it looks like we can not only control the on-set cameras LUT, but also the cameras exposure, FPS, ISO and a raft of other settings, all through an interface accessed on a web browser or an in-engine UI plug-in. This will enable our virtual production crew to quickly calibrate physical and virtual cameras and change any number of camera settings between and during takes.
ARRI changing LUT files during live streaming
ARRI CAP Settings