It is possible.

If you look at Cameron's "Avatar", hundreds of artists were put to work in the effort. Rendering farms processed the work.

It is extremely complicated and time consuming.

If you really want to try, start with something like a 30 second commercial. See how that goes. Keep in mind the time & effort you put into that 30 seconds will have to be done an additional 160 times (for an 80 minute feature). If you still want to do it, roll up your sleeves.

I'm not trying to discourage you, but I want you to know it can be done. It can look good. It WILL take a LOT of time and work.

Break a Leg!