Over the last couple of days I've been building a rig for this loveable little fella / vicious killer depending on which side of the cat / dog debate you're on. Most of it has been pretty straightforward so far. There's an rpIK for the shoulder joint, an rpIK for the front legs and spring IK for the back legs. The spine is made up of a spline IK and in the next hour I'm going to finish setting up the controls for the neck and tail. There have been a couple of issues though. Firstly the no flip leg. There seems to be three normal solutions for creating a no flip leg. Either using a knee twist and offset attribute plugged through a plusMinusAverage node and then back into the IK's twist attr, meaning you have to animate with attributes. Or creating a locator at the thigh joint, grouping aiming this at your foot control and parenting the PV under it, or finally creating a side PV then using the twist attr to animate the knee. As it stands I've gone with the first option but it'd be nice to have something a little more stable as the leg movements are quite extreme when a cat's running or jumping.
Secondly the reverse foot lock has been a bit of a learning curve. I've created a reverse lock joint chain but have since been told that there's a method of using IK's in the foot to do the same thing which gives you more control and the ability to tap the foot rather than just roll over it. Seeing as this isn't a jazz cat I don't think missing out on the toe tap will be too important this time but good to know!
I'll add a video of the rig in action to my vimeo channel when it's finished and after that the animation and final render too. As always any comments, questions or anything feel free to give me a shout.
Secondly the reverse foot lock has been a bit of a learning curve. I've created a reverse lock joint chain but have since been told that there's a method of using IK's in the foot to do the same thing which gives you more control and the ability to tap the foot rather than just roll over it. Seeing as this isn't a jazz cat I don't think missing out on the toe tap will be too important this time but good to know!
I'll add a video of the rig in action to my vimeo channel when it's finished and after that the animation and final render too. As always any comments, questions or anything feel free to give me a shout.