How to Groom Hair and Fur

At SIGGRAPH 2021, Sony Pictures Imageworks presented a Talk on its stand-alone grooming software solution, Fyber, which is currently being used on all upcoming Sony films. While you may not have a software like Fyber to use for your project, hair grooming is a great skill to learn and we’ve got the information you need to hone in on your hair and fur grooming abilities. We asked Brian Casper, CFX head of department at Sony Pictures Imageworks, to share his best tips for hair grooming.

1. Reference Is Key

A good reference will always make your job easier when starting a new groom. On most projects, you’ll be provided with some form of artwork or reference to base your work upon. Usually, this reference will consist of a series of production designer concept artwork, reference images pulled from the internet, or set photos. Ensuring you have multiple angles (i.e., front, back, left, right, etc.) will help you to match the profiles as best as possible. Your reference materials can also help in identifying key features of the hair or fur before starting the actual grooming process (i.e., waves, curliness, styling, etc.). During the reference and discovery phase, it’s often a good time to ask pertinent questions about the groom and usage: Is this a primary, secondary, or tertiary character? How close do we expect to get to camera? What type of acting or animation do we expect the character to perform? The answers to these questions will vary depending on the type of project (i.e., animated feature, VFX, video game, etc.)

2. Curve Layout

Curve layout is the foundation of any good groom. It provides the structure and framework for your hair. The artist will start by laying down a blocking pass of curves that will define the general shape and flow of the hairs. This is where the reference you’ve built comes in handy, especially when trying to match the concept art. Oftentimes, Brian’s team will bring the reference imagery into Maya or a related package to use as a background image plane that is matched up to the 3D model. This allows for precise alignment of the curves from multiple angles. Further refinements are almost always needed after presenting an initial pass to the client, as certain angles may reveal unforeseen problems when moving from 2D imagery to a fully realized 3D render.

3. Effects and Lookdev

Next, you move on to the process of adding in the effects that help define the look. For Brian’s team, the guide curves are brought into Fyber, where the final interpolated hairs are populated between the guide hairs. This is where Fyber is extremely powerful because it allows for a procedural workflow that provides real-time feedback to the artist. The artist can then start laying down some of the foundational nodes common to most grooms (i.e., clumping, wave, rotation, etc.). Once a suitable pass has been approved by the supervisor, the asset moves to the lookdev department, which is responsible for the final look of the hairs/fur in regard to material properties. Fyber’s hair/fur material/shader has been developed over the years to incorporate attributes that define how hair behaves to light in the real world. The groom is then rendered in many different lighting environments to find a suitable baseline for the look. Even with these adjustments, further refinements may be warranted once the character is dropped into an actual shot or sequence that is more representative of the project.

4. Final Adjustments

The final stage of a groom can often take longer than the initial setup. This is where you refine the details at a more granular level based on feedback from the client and/or supervisors. Once again, this is where Fyber really shines as the Sony team can see the final hairs/fur and any adjustments made will update almost immediately in the team’s viewport. Having this interactive feedback dramatically speeds up groom times versus older methodologies that required waiting for feedback on renders, which could take several minutes or hours, depending on the complexity.

Learn More About Fyber

Fyber is Sony Pictures Imageworks’ in-house hair and fur grooming software that is being used on all animated features and visual effects shows. As a node-based, stand-alone software, Fyber addresses the need for a faster, more interactive, and more artist friendly tool to generate any type of hair or fur, ranging from a character’s head hair to fully furred animals, with the goal to significantly lower grooming times and to create an improved learning experience for new artists.

Brian Casper is the CFX Head of Department at Sony Pictures Imageworks. His career spans 18 years at Imageworks and his credits include: Over the Moon, Spider-Man: Into the Spiderverse, Hotel Transylvania 2, Cloudy with a Chance of Meatballs and Surf’s Up to name a few. He initially started as an associate technical director in cfx on The Polar Express in 2003, working his way up through the ranks as a lead and supervisor, landing in his current role as CFX Head of Department. Prior to Imageworks, he spent 5 years working in video games at Midway Home Entertainment in San Diego, CA. He has been nominated for 2 Annie awards and 3 VES Awards, winning the VES award for Outstanding Effects Simulations in an Animated Feature Spider-Man: Into the Spider-Verse along with my colleagues Simon Corbaux, Ian Farnsworth and Powel Grochola.

Source：Siggraph