NEW YORK, April 26 --  Elon Musk and Sam Altman bonded over artificial intelligence in a project that became OpenAI, but a clash of visions will see the polarising figures face off in court in a trial that opens next week.

Silicon Valley lore traces their first meeting back to 2012, in an encounter prompted by investor Geoff Ralston.

Nearly 14 years younger than Musk, who was born in June of 1971, Altman was said to be impressed by the Tesla chief's powers of persuasion.

While yet to reach the age of 30, Altman already had a tech world reputation as a brilliant dealmaker.

Altman's unassuming, friendly demeanor contrasted sharply with Musk's abrasive style, but they shared an entrepreneurial spirit and a penchant for risk-taking....