If you edit the object (eg double click) you get a window where of the options is 'split'. It will generate a different object for each material. (all grouped into one group, so you can still manipulate it as a unit too)

"I paint that which comes from the imagination or from dreams, or from an unconscious drive. I photograph the things that I do not wish to paint, the things which already have an existence."
Man Ray, modernist painter
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