Hi! Your movies are awesome and I decided to learn how to do it. So, my question is with which program I should start and which programs do you use?
I used Maya for my short film and DreamWorks proprietary software for the features that I have worked on.
Software will come and go. My suggestion would be to start by getting familiar with the principles of animation. A good first step would be to dig through The Illusion of Life and The Animator’s Survival Kit.

