From what I read about it previously I think they do actually re-render the backgrounds in post
But the LED video walls serve two purposes: ensure the lighting and reflections on real objects in the scene match up with the CGI, and give the actors a visualisation to work with.
> From what I read about it previously I think they do actually re-render the backgrounds in post
All the videos and reels I've seen on this talk about "capturing the effects in-camera", so while I wouldn't be surprised if there's some integration and cleanup work to be done (particularly where the wall meets the set), it does sound like what is on the LED wall is what we see in the final footage and it's not just placeholder or pre-viz.
I think the biggest wins they get from it are that the actors can see what they're supposed to be standing in front of and that they get realistic lighting on the actors and other props from the environment
I think you're right. They use terms like "final pixel" when they talk about it, which leads me to believe they're capturing the background and not just rerendering in post.
But the LED video walls serve two purposes: ensure the lighting and reflections on real objects in the scene match up with the CGI, and give the actors a visualisation to work with.