No tearing them apart! James Franco and little brother Dave have a family day on set as they film The Disaster Artist about 'the worst film ever made'

They have done everything from comedies to dramas, block busters to indy releases but even these Hollywood veterans are in uncharted territory this time around.

James Franco and brother Dave stepped out on the set of The Disaster Artist in Los Angeles, California, on Thursday.

The film, which is about the making if cult hit and critically panned The Room, is the brothers' first ever movie together.

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Brother act: James Franco and brother Dave stepped out on the set of The Disaster Artist in Los Angeles, California, on Thursday

Not that you could tell it was them as they made their way through a back street in full costume.

James, in particular was unrecognizable as he strolled along in a bizarre ensemble and a long black wig.

The 37-year-old is playing The Room's enigmatic director, actor, writer and producer Tommy Wiseau, whose signature look is his long disheveled locks and his seemingly permanently attached sunglasses that only leave his face during filming.

History making: The film, which is about the making if cult hit and critically panned The Room, is the brothers' first ever movie together

James was dressed in a pair of blue cargo pants with a black knitted black and cream top.

Disguising him further the actor - who carried a big duffle and plastic case of books - had a bucked hat on his head.

Dave was not much easier to recognise in his blonde wig and facial hair.

The 30-year-old is playing actor Greg Sestero, who starred in the original film as the betraying best friend Mark. 

Is that you? James, in particular was unrecognizable as he strolled along in a bizarre ensemble and a long black wig

The man behind the magic: The 37-year-old is playing The Room's enigmatic director, actor, writer and producer,  Tommy Wiseau

Greg went on to write a behind-the-scenes book on the disastrous production on which the film is based and titled after.

Since its release in 2003, The Room has garnered a cult following despite being lambasted by critics as the 'worst film ever made'.

The movie - which mysteriously got funding for a $6 million budget - was famously described as 'The Citizen Kane of bad movies'.

However, it continues to get shown in theatres today where fans dress up as their favorite characters and yell out its most famous lines such as 'Oh hi, Mark', 'I did not hit her, I did not' and 'Lisa, you're tearing me apart'. 

Hair raising: Dave was not much easier to recognise in his blonde wig and facial hair to play The Room actor Greg Sestero

Adding to the intrigue: Seth also stars in the film as Sandy Schklair, who claims to be the original film's director

Also starring and producing the film about the making of a film, is Seth Rogen, who is playing Sandy Schklair.

Sandy was initially hired as a script supervisor, but claims due to Tommy's bizarre behaviour ended up 'directing the entire movie'.

Speaking to DailyMail.com he expressed concern at how he was going to be portrayed in the film, as Rogen had completely snubbed him. 

Life imitating art: Greg (pictured 2013) went on to write a behind-the-scenes book on the disastrous production on which the film is based and titled after

He said he offered to meet Rogen to give him background on the project, and had been in touch with him via 'a couple of emails' before contact 'dried up completely'.

'If they are making a movie that features me, that is going to be seen on millions of screens around the world... don't you think they should talk to me?' he asked.

'Everyone knew we were making a stupid, funny movie,' he added. 'Everyone except Tommy, who thought he was making Gone With The Wind.' 

James, like the man he is, playing is also directing the film which will see appearances from Zac Efron, Kate Upton, Jackie Weaver and, just announced, Alison Brie.

So bad it's good: The movie continues to get shown in theatres today where fans dress up as their favorite characters and yell out its most famous lines