M. Night Shyamalan has officially begun production on his Unbreakable and Split followup, titled Glass. Ever since Split became such a huge critical and financial success, fans of the film have been eagerly awaiting each new update that's been released for progress on its sequel. This was due in part to the fact that Split itself was ultimately revealed to also be a stealth sequel to his earlier hit Unbreakable. The next installment in the series will contain characters from both of those films, as both the title and synopsis for Glass confirm. For his part, Shyamalan has been continually updating social media with pre-production details, and his most recent post marked a significant date for the movie.

2000's Unbreakable is one of Shyamalan's most popular films, holding his trademark twist ending with a realistic and emotional superhero-origin slant. In Unbreakable, the indestructible David Dunn (Bruce Willis) found his inner power, only to discover that it was brought about by an act of evil by the frail 'Mr Glass' (Samuel L. Jackson as Elijah Price). Split takes place in the same universe as Unbreakable and showed how Kevin Wendell Crumb (James McAvoy) - an individual who has a rare and extreme case of Dissociative Identity Disorder - became the unnaturally strong 'The Beast', after kidnapping three innocent teenaged girls. The synopsis for Glass indicates that Dunn will clash with The Beast a number of times, in events seemingly orchestrated by Price.

Related: Read the Full Synopsis for Glass

On his Twitter account, Shyamalan has been marking the time with various posts, counting down the weeks until shooting actually starts on Glass. His most recent post confirmed that filming is now underway on Glass (at the time of writing this), in addition to making mention of successful rehearsals for the film. You can check out Shymalan's Twitter update, below:

With the social-media savvy director having already announced all the other important steps in the film's pre-production process, this might seem like a minor detail. Nevertheless, in terms of filming and schedules, it's good to know that the cameras are now rolling for real and that everything is on track for Glass' scheduled January 2019 release.

Shyamalan has grouped together a formidable cast for Glass. Along with the returning Willis, McAvoy, and Jackson, they will be joined by Anya Taylor-Joy, reprising her surviving role from Split. Also along for the ride will be Sara Paulson (American Horror Story), accompanied by more original cast members from Unbreakable.

Producer Jason Blum has described Glass as being a "very different" kind of superhero movie, similar to what Shyamalan had pretty much already delivered in the first two parts of this surprise trilogy. With Split clocking in over $276M at the worldwide box office, from a production budget of only $9m, it's safe to say that expectations have been set pretty high for Glass now. Fans of this unlikely shared movie universe are no doubt looking forward to learning more details about Glass' production straight from Shymalan's Twitter in the near future, too.

NEXT: Glass Will Have a Bigger Budget Than Split

Source: M. Night Shyamalan