Rigging Sprite Fright’s Spider

Sprite Fright is the new Open Movie, now in production. Here, Sprite Fright's rigger, Demeter Dzadik, explores the issues he's encountered rigging the film's creatures. As every animal comes with its own challenges, Met will go through them one by one -- devoting a short post to each. This first part focuses on Sprite Fright's spider.

Met begins at the beginning, with a short video showcasing the spider's initial rig. "We were keeping things pretty simple here," he explains. "For example, the eyelids are just a single shape key." For a rigger, the spider's legs are uniquely interesting. "Procedural rigging really shines when your character has eight limbs made of a billion bones each and you don't want to place them and name them by hand."

Eight legs and a billion bones: Met's first spider rig. [ View File ]

The second of Met's spider clips deals with a request from Lead Animator Rik Schutte. In it, Met adds an extra control to the base of the spider's legs, so that the spider can move each limb with greater fluidity.

A smoother spider. Met modifies his rig for more fluid movement. [ View File ]

To conclude, Met has a showcase of the spider's current state -- with all issues (so far) addressed. He says, "The thing is, this little guy has eight legs, and that means he has to crawl, jump and fall. He even gets resuscitated with mouth-to-mouth. So it wouldn't hurt to give each of those eight legs the versatility they need but with minimal adjustments. That's because, at the end of the day, the spider is not a main character and the time budget for rigging is limited."

Met's tour of the spider rig so far. Follow the link for work related to Sprite Fright rigging. [ View File ]

Met comments on the video above: "As you can see in the rig UI panel in the sidebar, each of those eight legs have IK/FK switching and snapping, FK Hinge, parent switching, and IK pole. Basically, the whole shebang. When you count all eight legs, those things add up to hundreds of helper bones. Now imagine having to duplicate that rig setup eight times, renaming all the things that need to be renamed, and pushing things into the correct positions. It would be a nightmare!"

Met continues, "Because of the procedural workflow, we only had to do that duplication, positioning and renaming in the metarig, which means three bones per leg. Then I can just press the Generate button, which I have bound to a hotkey, and I get those eight leg rigs with all their features and hundreds of helper bones with the correct naming and everything. All already hooked up to the rig UI. Much less painful!"

"It's also interesting to see how simple the eyelid rig is for this guy. It's just two controls hooked up to some blink shape keys, and a root control to rotate it around its forward axis. And that's really all the detail we needed here. Spidey just needs to express some pretty basic emotions: hungry and angry, or just hangry!"

For more of Met's work, you can follow his weekly production logs here.

And see this post on rig performance, and this one describing Met's thoughts on what he's learned from the Sprite Fright production.

Very soon indeed, Met will share another rigging breakdown for a Sprite Fright creature.