Why is it so expensive to make CGI in a movie?

Question

I liked that Final Fantasy : Spirits Within movie because it looked very real. Also I heard that Transformers wasn't as good as it should have been because they didn't used enough CGI because it costs a lost of money. Why is it so costly to make?

Answer 1

It takes time. CGI render is something like 3D games rendering, except that it is folds more complex and takes a hell lot of time to render.

You create a city in 3d, put your character in it, put all light source (the sun for example) and then you let the computer do the drawing, like calculate how every part of it looks like under the lighting effect, shadows and reflection. Modern CGI such as cars use ray tracing method, which simulate lights and calculate how light bounces off every surface. This creates realistic reflection on the car's surface. But to render (computer doing the calculation) one frame, it could takes hours to days.

And they use multiple workstations (computer) to do the calculation. I think they have a farm of more than 100 computers to do the calculations, yet it takes hours just to render one frame. Of course as you can guess, during production, these computers will be running 24/7

Answer 2

It's a pure scam. It costs a lot because it can. As with everything which is limited to a few companies they charge the earth as unless you use them you're stuck. Yes it's time and labour intensive but it's also massively overpriced considering there's no physical resources used.

Answer 3

they need to make the movie look more real....