Rigged for Success
Issue: Volume 38 Issue 5: (Sep/Oct 2015)

Rigged for Success

Animation students are always eager to learn the fine points of their craft. However, finding interesting (and free) rigs to use for animating original content for their portfolios can be quite a challenge. A challenge for students in the Digital Art & Animation program at Cogswell College in Sunnyvale, California, as well as countless students around the world. And, a challenge for instructors needing rigs to teach their students.

Recognizing this issue, students at Cogswell have created 3D animatable rigs for 12 original digital characters through the Digital Art & Animation program’s in-house character project called Avatarah. Cogswell students will use the rigs, and while some will remain exclusive to those students, a number will be released to the general public through open source.

“There has always been a constant demand for new and exciting 3D animation rigs that can be accessed online,” says Jonali Bhattacharyya, assistant professor at Cogswell’s Digital Art & Animation program who is spearheading the student--developed 3D animatable rigs project in concert with Sergio Sykes, adjunct faculty member at Cogswell who was formerly with Massive Black, a production artwork and asset outsourcing studio. 

As Bhattacharyya explains, Avatarah is a cross-disciplinary project for creating high-quality 3D character rigs. The characters are designed, modeled, textured, and rigged in-house by students from various disciplines at the school who are selected for the tasks based on their expertise. Some of the work was done during an elective class, though the majority of it was accomplished after hours. 

Valuable Teaching Tool

Until now, the school did not own any original 3D characters, and to teach rigging and animation classes, the instructors had to borrow rigs from other outlets. Although there is a growing number of solid bipedal rigs available, it’s still difficult to find good creatures and quadrupeds on which to practice animation techniques, says Bhattacharyya.

As a result, Bhattacharyya proposed the project to help bring consistency to the animation courses, with the plan to have all the instructors at Cogs-well teaching with the same rigs, following a consistent art design, and having an internal support team. 

The idea for the project was first discussed in mid-2013, and after some initial attempts, the school began full production last February and completed the models at the end of 2014. “We’re currently gauging interest among the campus community and those at large to consider restarting the project with fresh ideas, new characters, and tools to help with rigging and animation,” says Bhattacharyya. “We plan to involve more departments in our project going forward and really show what Cogswell has to offer.”

According to Bhattacharyya, there is always a demand for high-quality rigs, prompting the school to publicly offer some of the Avatarah characters. “With the amount of effort that went into making rigs that are robust enough for the needs of our college, we decided to release the rigs to the community at large, and are excited to see how the community makes use of our characters in their own creative projects,” she says. The rigs are available for Mac, PC, and Linux.

As for the students, they have an opportunity to impact the school’s program and to create something for public usage, which is more tangible than traditional animation assignments, Bhattacharyya notes. “And, we’d like to have our students graduate with work that has its own identity.” 

Beauty Is Skin Deep

The first round of content included 12 sets of rigs covering the needs of the school’s animation and rigging classes: quadrupeds, bipeds, and primitives, all designed to fulfill the needs of the curriculum.

This past spring, Cogswell the Dragon became the first Avatarah character to be available without restriction from the initial group, available under a Creative Commons license, including all the source assets. Thus, users can go beyond just animating the rigs – they can rig the characters themselves or make their own textures and accessories. (Cogswell the Dragon can be downloaded from www.cogswell.edu.) Among the 11 other characters created are Toothy the saber-toothed tiger, Snowy the dog, Thunder the horse, Chippy the squirrel, Chubby the rabbit, Flappy the bird, and others. Some will be widely available, while others will remain exclusive to Cogswell.

The character designs were driven by the need to have a wide range of animators using the rigs for various projects. 

Sykes and Bhattacharyya, both of whom are well versed in production cycles within the game industry, created a pipeline not unlike that of a studio production for the project.

Artists Katie Fortune and Michael Sardi worked closely
with Bhattacharyya, who served as project lead, to come up with designs that suited in-class assignments and a level of complexity in terms of performance. A final design was chosen based on the structure, flow, appeal, and functionality of the character. Afterward, the modeling team of Robert Garcia and Steven Mortensen brought the characters to life through 3D sculpts in Pixologic’s ZBrush; later, they retopologized the high-res sculpts for use in Autodesk’s Maya. Textures were generated using a combination of The Foundry’s Mari, Knald Technologies’ Knald for bake-quality textures, and Adobe’s Photoshop.

The rigs themselves were developed by Sykes, who served as rigging lead, along with Wambugu Kaigwa, who Sykes calls “one of my standout students.” Using Maya, they created the rigs with conventional features: IK/FK switching for limbs and the spine, the ability to change the parent of the controls mid-animation using space-switching, and rotation orders set up in such a way to reduce gimbal locking as much as possible. 

“The rigs were built with the clever use of spline IKs, Bezier curves, joint layering, and various implementations of blendshapes,” Sykes says. “As development evolved, we authored a library of auto-rig scripts in PyMEL in order to maintain consistency between the rigs, regardless of which TD was assigned to the task.”

During development, the modelers collaborated with the riggers to ensure that the mesh topology was on track. Then the animators tested the completed rigs, offered input, and ensured there were no major issues. 

Additional software and plug-ins were incorporated into parts of the pipeline leading up to the completed rig. To help expedite skinning, the team used the ngSkinTools plug-in, which enables users to mirror weights across a large number of overlapping joints, as well as iterate on skinning deformation in a non-destructive fashion via its built-in skin layering system. Blendshapes for the characters were mostly done in Autodesk’s Mudbox, whose layering system behaves similar to the corrective blendshapes in Maya and whose sculpting controls are fast. 

Each rig has its own development and testing cycle and undergoes an extensive amount of animation within Cogswell’s curriculum in various student projects to ensure it is stable. “Dynamic simplicity was a theme throughout the project. It was important for the rigs to have a simple control scheme to make the characters accessible to different skill levels, while also offering just enough detail and subtle motion so students can really nail down all the animation principles,” says Sykes. 

Which rig was the most complex? In Sykes’ opinion, it was the Henry and Caroline human bipeds. Because they will be used the most within the college’s curriculum, they encompass everything needed by multiple animation instructors, ranging from simple and subtle animations and extreme actions to locomotive cycles. 

“With full facial rigs and detailed control for clothing and secondary motion, Henry and Caroline contain the greatest amount of controls,” Sykes says. Emily Wiebe, Matt Peponis, and Marne Pool made up the testing team, providing the feedback needed to make the controls as animator-friendly as possible. 

As for the additional characters, the group will continue to develop the rigs internally and will release them when they are ready. In the meantime, Sykes and Bhattacharyya are monitoring how the first character is being received and are gathering feedback about the models.

The advantages of such a project are obvious to the students and instructors who will be using the rigs. “This is a huge platform by which our students can really start to get their names out there,” Bhattacharyya adds. “We hope Project Avatarah will enable Cogswell students to create an identity of their own within the rapidly exploding world of animation.”