They call themselves Hollywood's best-kept secret: India's animators, long-time partners for the likes of Walt Disney Co, are reaping the rewards of surging demand for visual effects and gaining the confidence to venture out on their own. India's animation industry generated revenue worth Rs 4,490 crore ($675.7 million) in 2014, a 13 per cent increase from the previous year, according to data from a FICCI-KPMG report on media and entertainment industry. The industry is expected to double in size to Rs 9,550 crore within five years, as Hollywood studios tap a large pool of low-cost, English-speaking animators who are familiar with Western culture. So far, animators based in India have created crowd scenes and props for the Emmy award-winning TV series "Game of Thrones" as well as more prominent visual effects for films including Disney's 2014 Angelina Jolie movie "Maleficent" and Dreamworks Animation's "How to Train Your Dragon...