Learning the Art of Rotoscoping

Rotoscoping – a technique that involves drawing or painting over an element in live-action footage frame by frame (as to create a matte or a realistic animation). – Merriam Webster

As one of the foundational skills of Compositing and traditionally an entry-level path that I followed to the role of Compositor, rotoscoping (roto) is often labelled: “tedious” but “essential.” It is a significant part of the secret answer to the question: “How did they put those characters on a new background without using a blue screen or green screen?” But with the existence of BG Prep departments, outsourcing, developments in AI, and shows being filmed on stages with LED screen backgrounds, is knowing how to roto still worth the time it takes to develop the skill?

Here are 3 approaches a Compositor might take to learning rotoscoping:

1. Avoid it – Why bother when roto artists will do most of the work for me, I don’t enjoy it, and I’m not particularly good at it?

2. Dive into it – Learn from reliable sources how to create pixel perfect mattes using Nuke, Mocha, and Silhouette. Demonstrate your skills by showing your mattes and the shapes you drew to create them for multiple shots with different challenges. Invest a lot of time in practice.

3. Follow the current – Ask: “What is the end goal of this roto and why is it needed for the composite (comp)?” Look at the context and prioritize the pixels and frames that are most important for the comp. Learn which tools and methods are being used in VFX studios right now to generate mattes. Experiment with AI-assisted roto, learn how to improve its results, and consider when it is or isn’t practical. Why roto a shot and do zero comp work with the result when you’re studying to become a compositor?

I’ve heard directly from numerous Compositing Supervisors how much they appreciate Compositors who can roto well: they save the studios time and money (and have a positive, can-do attitude). AI-assisted roto has problems, limitations, and still needs guidance. And you will only ever receive roto that works for your composite, roto that doesn’t, or no roto at all. That means in 2 out of 3 scenarios, you need new roto. So I cannot recommend avoiding roto: option 1.

The second option is how I used to teach roto to students. It’s not bad, especially if you’re aiming for a role in Rotopaint before becoming a Compositor. But it takes time. Presently, teaching at Alpha Chromatica, I’m using option 3, and I am impressed with the students’ rapid progress. They are rotoscoping with a purpose, beyond only aiming for accurate and consistent edges. They are considering the comp and the big picture.

Rotoscoping also builds and exhibits character. You need determination, self-discipline, attention to detail, and good organizational skills to complete a challenging roto task. Roto artists are like marathon athletes. Before considering how good or how fast someone is, you need to know if they can finish a race. So when a Compositing Supervisor or Recruiter asks me: “Is this student reliable?,” I can confidently reply: “Yes.”

I look forward to sharing the work done by our current students with you.

    Leave a Reply

    Your email address will not be published. Required fields are marked *