'Insane' CGI from Mission: Impossible 7 had people thinking sequences were 'filmed for real'

The evolution of CGI technology has come a long way.

Scenes that have resurfaced from Planet of the Apes have had fans in fits of giggles. But the Mission Impossible franchise puts CGI in a whole different light.

Known for its crazy stunts and intense fight scenes, it wouldn't be a Mission Impossible movie without action scenes being 90% of the film.

One YouTube video shows the magic behind Mission Impossible 7: Dead Reckoning, and the true power of CGI.

In the video posted by Industrial Light & Magic, action-filled frames have been broken down into before-and-after shots.

Mission Impossible is known for it's realistically-looking action shots / ILM/Paramount Pictures

Tom Cruise is known for doing his own stunts - but CGI digitally enhances many scenes' backdrop to make it appear more risky and death-defying.

In one train scene, the video shows Cruise and his co-star - Hayley Atwell - are on top of a moving train. Although they are on top of a speeding train for real - going 60 mph - the CGI enhances the whole backscene.

You can see the original background looking quite plain and not much to look at, but with CGI, you can see the added mountains, trees and enhanced green colours, making it appear more cinematically.

The insane part is that part of the train does actually fall off the cliff as well, but the creative team enhanced the surrounding impact of the fall to make it look more realistic.

In another scene where Cruise and Atwell are running up a train that's falling off a cliff, the acting duo aren't actually falling off a cliff - as real as it looks.

The CGI makes it hard to tell which scenes were real and which weren't / ILM/Paramount Pictures

Instead, the train is attached to a pulley and as it's flung upwards - sort of like an amusement park ride - it reflects the realism and struggle of climbing up a vertical structure.

The train is plain inside to start, but the CGI adds in the dramatic falling tables, chairs and debris to make Cruise and Atwell's climb look a lot more like a scene out of Uncharted.

And let's not forget the most memorable moment of the entire film where Cruise drives a dirtbike off a cliff before he parachutes away. Behind the scenes, the crew set up a massive ramp to make Cruise's drive-up easier. CGI then impressively covered up the ramp, blending in the surrounding rocks and greenery.

Cruise has highlighted the challenges in other behind-the-scenes footage, including the last fight scene whereby he claimed it a 'trial by fire.'