The Alliance of Motion Picture and Television Producers has unveiled a study to back up its call for more arts training in K-12 classes as a way to meet the need for animation and digital effects workers.The report, called “Making Digits Dance: Visual Effects and Animation Careers in the Entertainment Industry,” was released last week through its Public Affairs Coalition at a forum in Mountain View on how to keep digital jobs in the state. A companion study of Northern California multimedia and computer firms also was unveiled. Business leaders in Hollywood, Silicon Valley and San Francisco have formed a group called SkillsNet, designed to solve problems with the shortage of artistically trained and techno-savvy workers. They have argued that the reduction of arts classes in public schools has created a dearth of workers with well-rounded education in both areas. The conclusions in the report came as little surprise: potential new workers need arts education earlier in life. Much of the report was a survey of which skills are needed in certain segments, such as a computer artists or character effect animator. It identified more than 300 firms in California producing animation and digital effects. The number employed in the animation area was estimated at about 3,500 to 4,000, twice as many as a decade ago. The study indicates that about 6,000 are employed in digital visual effects, compared to virtually none a decade ago.