This documentary presents remarks from Emmerich, Goulekas, visual effects supervisors Greg and Colin Strause, digital effects supervisor Bryan Grill, CG supervisor David Prescott, visual effects supervisor Remo Balcells, visual effects supervisor Christopher Horvath, ILM animation supervisor Dan Taylor, ILM creature development supervisor Corey Rosen, ILM CG supervisor Gregor Lakner, and ILM visual effects art director Alex Laurant. The piece starts with a look at the effects created for the opening sequence and proceeds through shots from space, tornadoes, the helicopter crash, the storm tide, the wolves, and the New York “big freeze” and its aftereffects. Almost inevitably, “Envelope” can be a bit dry. However, it fares as a pretty complete examination of all the movie’s effects. It gets into the elements well, as it never becomes too technical or wonky. It moves quickly and offers as a good overview of the issues.