I guess it depends on the definition of "heavy use." I know in Tron a few scenes were CG, and there were a few CG+live-action bits, but the majority was filmed on normal physical sets in high-contrast, then painstakingly hand-processed[1] to add the neon "glow".

[1] https://filmschoolrejects.com/tron-costumes-glowing-effect/ Thanks legions of Taiwanese animators (:

From your link: >The 1982 Disney movie is privy to a remarkable number of firsts: the first feature-length film to combine CGI and live-action; the first talking and moving CGI character; the first film to combine a CGI character and a live-action one; the first fully CGI backgrounds… The list goes on and on.

Sounds pretty heavy to me.

And the film OP mentioned Oliver & Company:

>Eleven minutes of the film used "computer-assisted imagery" such as the skyscrapers, the taxi cabs, trains, Fagin's scooter-cart, and the climactic subway chase

I think Tron wins in terms of CGI

But Disney financed and distributed Tron. It wasn't made by a Disney Studio, and most of the animation was outsourced to a Taiwanese studio because Disney wouldn't lend any of their own talent. So I think it's fair to say that Oliver & Company is the first Disney-made film to use CGI.

The Great Mouse Detective (1986) was earlier and the ending sequence is CG (printed out and traced onto cels so traditional 2D characters could be drawn on top).

That's a good point. What's funny is that "The Great Mouse Detective" was actually the film I was thinking of this whole time - I believe the ending sequence took place in Big Ben, and it looks quite good by 2024 standards. But I forgot the name of the movie and assumed it was "Oliver & Company" because Oliver is a plausible name for an English mouse :)

And large amounts of the "computer" graphics in Tron are hand drawn.

Still lots of CGI.

Probably meant “Disney animated feature”.