What was the first Disney movie to use CGI (computer-generated imagery) in 1985?

"The Black Cauldron" is a 1985 American animated adventure dark fantasy film produced by Walt Disney Feature Animation in association with Silver Screen Partners II and released by Walt Disney Pictures.

Set in the mythical land of Prydain during the Early Middle Ages, the film centers on the evil Horned King who hopes to secure an ancient magical cauldron that will aid him in his desire to conquer the world. He is opposed by a young pig keeper named Taran, the young princess Eilonwy, the bard Fflewddur Fflam, and a wild creature named Gurgi who seek to destroy the cauldron, to prevent the Horned King from ruling the world.

The Black Cauldron is notable for being Disney's first animated feature film to incorporate computer-generated imagery (CGI) in its animation for bubbles, a boat, a floating orb of light, and the cauldron itself.