I tried to find data but couldn't quickly, so maybe someone else can find a comparison study.
So instead, fwiw, anecdote: I work for a film production company and we ingest assets all the time from high end VFX houses. It's always from Unreal / used in Unreal in my experience. That's in LA/ Hollywood and high end productions. For all I know they use a lot of Unity in Bollywood or Europe.
Not to mention most of those use ILM Stagecraft which, despite being Unreal-based in its first version, has been using a custom engine for some time now.
Anecdotally, I've heard the same thing. Lots of articles will say things like, "ILM increased the resolution of StageCraft with its in-house renderer, Helios" but never explicitly say they dropped Unreal or exactly what changed.
charitably asserting that you are right in the sense that it can be found. I'm a vfx compositor turned devops crossover. The tooling at this point is decades old, in concept. There are many "reimagining"s of vfx pipelines with Unreal at its core, but even these pipes have flame/nuke/fusion somewhere downstream.
Even smaller than the unreal operators is the pool of users that are purists enough to try and keep it all in-box.
Maya, Nuke, Houdini. These are the kings of the vfx world you were looking for if youre talking in the tens of thousands of artists out there, using pipelines that are conceptually 20 years in the making in some parts. The switch from Shake to Nuke was ~15 years ago and theres _still_ nothing good enough to replace it. Foundry scrapes as much money from us as possible because its a good product.
Unreal is amazing. Our shop is wrapping a project using it as the lighting pipeline, delivering to a Nuke team.
That sounds interesting! How come? Been doing devops stuff for a few years by now but also have some background in the Unity/HCI space which I enjoyed a lot. I'd be curious how this combination might be applicable in the VFX/media production industry.
I've also been on the fence of learning Unreal for a while now. Maybe you could shoot me an email (address is in my bio)? I'd be very interested in how the industry works outside the 'classic' VFX artist space.
Mainly because in 2019 I was offered an opportunity to be the "tech guy" for a small startup and you know how those go. Since I was alone it just became a DevOps/dev/helpdesk role over time.
Where are you getting this information? Not only have I never heard of this, "the major VFX vendors" don't really do 'virtual production' or previz, with the exception of the ILM stagecraft stuff.
I haven't heard of anyone using unreal for final frame rendering in film.
I think they're overselling it, but Unreal is fairly heavily being used in the early parts of pipelines at various studios, certainly more than Unity engine itself...
i.e. MPC had significant use of Unreal on set for mocap, Framestore has Unreal setup for previs and mocap (they hired some ex-games devs with Unreal experience to work on it)
ILM stagecraft is the 'hero' example (and as mentioned, they've got Helios now), but various studios are experimenting with it in various departments.
Disclaimer: I work for Weta, and above doesn't reflect anything about Weta (Gazebo, etc), it's all from friends/ex-colleagues at other studios...
Search YouTube for "Unreal" film previews. There are so many out there that were all realized with the Unreal engine. Maybe it's the algorithm, but all I see is stuff done in Unreal and I haven't seen anything done in Unity.
I searched for that and 'unreal engine film preview'. There were a few cinematics that have been made, but there was nothing that had to do with major vfx studios or even upcoming mainstream films.
So instead, fwiw, anecdote: I work for a film production company and we ingest assets all the time from high end VFX houses. It's always from Unreal / used in Unreal in my experience. That's in LA/ Hollywood and high end productions. For all I know they use a lot of Unity in Bollywood or Europe.