Bill Paxton's death has been ''brutal'' on his friends.

The 'Twister' actor passed away last month at the age of 61, when he suffered a stroke 11 days after undergoing surgery to replace a heart valve and correct an aortic aneurysm and Nathan Morlando, who directed his final film 'Mean Dreams', is still in shock.

He told PEOPLE: ''It was brutal. I was filled with disbelief. Bill had just taken me out for a beautiful lunch so our wives could meet, and we were becoming really close. Bill was becoming like a big brother to me and I was very grateful for that. I was really looking forward to our future together as friends and collaborators. So it was a lot of crying. We spent days crying actually, reflecting on him and his greatness and generosity.''

And Nathan praised the 'Titanic' actor for inspiring the cast and crew of the indie movie.

He said: ''When he came up to Northern Ontario, he had left beautiful, warm L.A. weather, where he was shooting a movie with Tom Hanks. Then he lands in Canada, where it was freezing cold, he was making no money, and the whole production was a physical challenge. And he was just incredible, he did it for the role and it was just inspiring to all of us.

''The moment you meet Bill, especially if he notices that you're seeing him in a certain way, he breaks that down immediately. He is just a lovely, generous human being and he treats everybody with the same respect and regard. He's just filled with such respect for people, and he instantly wasn't the star, he was the artist.

''It was freezing outside for the shoot, much colder than it looks onscreen. The crew behind the camera was wearing literal arctic gear; we were filming outside for upwards of 15 hours a day. Bill's in a thin leather jacket and a thin shirt and he's toughing it out. His attitude on set was incredible. Even if he was not on camera, he was always an inspiring presence on set for others and he become everybody's friend. It was so genuine.

''This was a guy who was going to keep going. He was always in a new stage of creativity, and he was really excited about what was coming. It's so hard to comprehend that he's gone, he's one of those forces that you believe will always exist.''