So we have a setup with the Unreal 3+3 Mixed Cam Compound, 2 tracked Cameras and a DSLR on a tripod as a virtual camera.
With the tracked cameras I can physically truck, dolly, raise and lower the pedestal, pan, tilt and zoom as needed and with the tracking system set up correctly this will give me realistic perspectives with no noticable shifting between the background and the actors in front of it. So far, so good. It's different with the virtual camera though...
I understand that there are limits to what can be done here; the billboard is only a 2D object, so trucking or panning too far will make things look unrealistic. But maybe someone has got a few workflow tips for me here.
First of all I need to correctly set up a default position for the VCAM. In my understanding that is the case if I can switch between input and final on its monitor panel and the actor's picture does not change at all, while at the same time he or she is correctly positioned relative to the floor in final. Any tips or shortcuts here? Locking the billboard to the camera only sticks the actor in front of it, but I also need to have the virtual camera in the virtual set in the correct spot, matching the physical position of the camera, right?
Then there is the issue of initially matching the FoV of the virtual camera vs. the physical camera. Unfortunately the camera (a Nikon Z8 with a Tamron 35-150 set at 35mm putting out 4K) does not give me a data readout here; doing it manually with a measuring tape sort of works, but is there a way to do this optically? It's really time consuming to do by trial and error, but I need to optimize this; atm virtual pans result in a noticable shift between the actors and the background.
I have read this: https://aximmetry.com/learn/virtual-production-workflow/preparation-of-the-production-environment-phase-i/starting-with-aximmetry/aximmetry-composer/camera-mover-mouse-control/?srsltid=AfmBOooR3713EwPzJr3lPNCcZEtu4SZW6mr5KE-nUpFEJtqXcdrj_DsThttps://aximmetry.com/learn/virtual-production-workflow/preparation-of-the-production-environment-phase-i/starting-with-aximmetry/aximmetry-composer/camera-mover-mouse-control/?srsltid=AfmBOooR3713EwPzJr3lPNCcZEtu4SZW6mr5KE-nUpFEJtqXcdrj_DsT
and somehow pressing O does not do anything...?
It would help if you posted some test videos to illustrate the issue. The main thing you need to do is to make sure the billboard is actually placed at the correct position in 3D space. Make sure it’s placed so that the feet are perfectly aligned to the floor by lowering it until the floor clips the feet and the raise it carefully again.
Bigger virtual camera moves really only work if there’s no depth or parallax in the keyed foreground. So a single person standing in front of the camera works great, but a group of people sitting in a circle will quickly reveal the 2D nature of the plane.
As for matching the real and virtual camera moves, I’ve found it’s best to have as much distance between the talent and the physical camera as possible and zoom in to maximize resolution. Have the camera at about 1 meter from the floor.
When trying to determine if the perspective is realistic, it helps to turn off the keyer to see how well the the real floor plane aligns with the virtual floor. If you have the time, put out a ladder aligned with the center of the camera to better see the vanishing point. Having a virtual 3D human (matching the height of the talent) at the same location in the scene also helps determining the correct scale and perspective. Add a GetAximmetryTransform to quickly place and remove the 3D model.