Our character workflow series continues as we dive right into rigging and skinning. We mentioned previously that it’s important to leave some room between the various geometry elements in order to avoid interpenetration. In the case of our character this proved to be important indeed as you will see in a moment. Of course these gaps shouldn’t be too big either, or else things will start looking unnatural.
We used Maya’s HumanIK to quickly generate a default rig. Requirements for a character will often differ from what the default rig provides, but nonetheless it’s a great starting point and can be extended or modified easily. For instance, we added fingers to the rig because we need decent hand animation for all of our spell-casting characters.
It’s advisable to model the character in a standard T-pose or whichever other pose is best suited for your bones setup. Then you can select the character geometry and let HumanIK calculate the rig for you. It’s important that the Definition section of the rig displays everything in green, that way you know you’re good to go. If there are any issues at this stage, you will have difficulty transferring the animation in Unity later on.
With regards to skinning, things have certainly gotten a lot better over the last 15 to 20 years. Maya’s Bind Skin feature does a decent job at distributing bone weights across your character’s geometry. Still, decent is not perfect, so manual cleanup can’t be avoided.
To identify problem areas, we like to put the character in a “Van Damme” or a “Matrix” pose. It’s very unlikely that the character will ever hit such extreme angles in the game, but if we can get all deformation to look clean in those poses, they will also look clean during all other types of animation we may throw at the rig.
After putting the Paint Skin Weights tool to good use and ensuring that our villain can do the splits without spazzing out, he’s ready for Unity. We simulate the coat in realtime, it’s not controlled by the bones animation, and if you’re curious what the end result of all this work looks like, we have an in-engine video coming up for you very soon.