A fascinating yet flawed movie, I Am Legend was ultimately let down by some uneven visual effects.

We spoke to director Francis Lawrence about just what went wrong…

The extraordinary overgrown New York landscape.

Will Smiths lonely, haunted performance.

Akiva Goldsman and Mark Protosevichs economical script which, for the first hour at least, is entirely convincing.

I really wanted to do a movie that I could approach in a more organic way, Lawrence said.

I was really disappointed by that part of the process onI Am Legend.

I then brought up the subject of the make-up effects footage mentioned earlier.

I wanted to do it with real people in the beginning, Lawrence said.

We actually cast this huge group of people, like, 50 dancers and parkour guys.

And we shaved their heads and they worked with movement coaches and we created this behaviour for everybody.

And we built these suits, this guy called Christien Tinsley built them.

We actually started to shoot with them.

They had to be aggressive, and I just wasnt convinced it was going to work.

When I saw the dailies, I broke out into a cold sweat.

It didnt work at all.

And one night, we shut that all down and decided we were going to go for CG.

We basically postponed anything we were going to shoot with creatures until much later.

We went to a whole other design process.

Sadly, the final rush to complete the film resulted in the variable effects work in the final cut.

It just kills it.

I think thats also one of the mistakes.

They should have just been hidden.

They should have been much more hidden in shadows, and barely getting a sense of movement.

It would have been much more viscerally scary.