‘Avatar’ director James Cameron has been sued for the second time in nearly as many weeks by someone claiming to have come up with the idea for the sci-fi mega-hit.Cameron’s attorney, Bert Fields, and Fox both slammed the latest suit by science fiction writer Bryant Moore as without merit. Moore, TMZ first reported Monday, is seeking more than $2 billion — yes, with a ‘b’ — from Cameron and 20th Century Fox, claiming that Cameron used his screenplays for the movies ‘Aquatica’ and ‘Descendants: The Pollination’ as the basis for the 2009 film.Moore is seeking $1.5 billion in actual damages, plus another $1 billion in punitive damages.‘Mr. Cameron was demonstrably the author of ‘Avatar,’’ Fields told TheWrap. ‘We can prove that, and we intend to prove that in court.’ Moore’s claim — and, for that matter, any claim alleging that someone other than Cameron had authored the movie — is ‘entirely without merit,’ according to his attorney. A spokesperson for Fox called the suit ‘baseless,’ adding, ‘we look forward to vigorously defending our position.’According to TMZ, Moore cites numerous similarities between the projects, including bio-luminescent plant life, spiritual connections to environment and reincarnation, and the appearance of mist in a scene — yes, the appearance of mist in a scene.Earlier this month, Eric Ryder filed suit against Cameron in Los Angeles Superior Court, alleging that ‘Avatar’ was largely lifted from his story idea, ‘and ‘liberally and substantially uses material’ that fell under his agreement with Lightstorm. Ryder claimed to have entered an agreement with Cameron’s production company, Lightstorm Entertainment, to develop a movie based on one of his stories.