RE:Vision Effects released ReelSmart Twixtor as a Sparks plugin for Discreet systems that support Sparks version 2.5 or later (Inferno 2.5, Flame 5.5, Flint 2.5, Fire 2.5 and Smoke 2.5 and later). Irix 6.5 and later is currently required. Twixtor intelligently slows down, speeds up or changes the frame rate of your image sequences.