What started out a decade ago as a ragtag bunch of 25 artists in rural North Carolina is now one of the hottest group exhibitions in the Chelsea gallery district. This spring, Joshua Liner Gallery has tapped the global Barnstormers collective to bring its dizzying brand of murals — or “motion paintings” — to the largest show the venue has ever organized. With their numbers swelling to 35 (including appearances by Swoon, Doze Green, ROSTARR, Ryan McGinness, and founder David Ellis), the Barnstormers use image, sound, materials, and technology to connect with contemporary culture.