3dsmax - Cat Rig CatMotion walk cycle. Knees keep popping between straight and bent.

sr3d

I have a problem with the cat rig CatMotion walk cycle. The knees keep popping between straight and bent during the walk cycle.  I've been trying for hours to fix it with little success. 

https://www.youtube.com/watch?v=RtcK5gQ63dI

Is there an in depth tutorial that covers mastering Cat Rig CatMotion walk cycles? 

musashidan

This is a common issue when animating and can easily be fixed by lowering the centre of gravity. In Catmotion you can do this procedurally in the Cat window, or just manually tweak the pelvis bone in your rig.

sr3d

musashidan said:

This is a common issue when animating and can easily be fixed by lowering the centre of gravity. In Catmotion you can do this procedurally in the Cat window, or just manually tweak the pelvis bone in your rig.

Thanks, I will try that!

If I adjust the length of the animation from 100 to 60, do I also need to modify each of TIME keyframe intervals?

if animation length = 100
then PELVIS LIFT time intervals = 0,25,50,75

If animation length = 60 then
change PELVIS LIFT time intervals to 0,15,30,45 ??

sr3d

CatMotion is a god damn nightmare, there has got to be a better rigging and animation solution that doesn't involve me reinventing the wheel.

Mark Dygert

I say this because I was once in your place...

CAT is pretty decent and very flexible, but you do give up some freedom in order for the system to function, it's that way with all automated rigging solutions. There always have to be rules for a procedural motion system like that to work. 

It's nearly impossible to design an open rigging system that won't gimbal, has procedural motion, and works with clips, is customizable and works as everyone wants it to. At best you can redesign a custom rigging system to fit your needs, but everyone that wants to use it another way will bitch up a storm when the rules you create don't match what they want to do.

You can't please everyone. Those who choose rigging automation over creating a rig from scratch, don't have much room to complain, that's the trade off. CAT does a pretty good job of trying to rig a lot of very diverse creatures while letting you Frankenstein a rig to your needs but even then, there are rules you have to play by.

For max there isn't much because Biped and CAT are already in max. Biped is rock solid, production tested, has a lot of support for working with animation clips and transferring motion from one biped to another. The IK/FK at the same time will spoil you. It won't ever gimbal on you, because it works on Quaternion, but that won't let you slide X past Y and there has to be a key on every track, which I don't mind giving up, its a small price to pay for hours of cleaner animation with less headaches.

Besides most experienced animators won't use procedural motion unless it's for temporary, blocking purposes, then they throw it out and start animating. Most won't touch procedural motion, they will quickly hand key a few poses, use an existing cycle they did previously or they'll use mocap. So really procedural motion is an under used feature by most animators. It's really there for people who can't animate a walk cycle... which means they probably can't rig either so they should probable be thankful that someone even put a semi-robust system in place =P

For me personally, Biped and CAT spoiled me rotten. I have insanely high standards for custom rigs because of it and I mostly work in Maya now. I complained when I was learning to use them, because they didn't work like most rigs I had encountered. But once I got used to their workflow and was able to leverage the tools as intended, I came to appreciate what they could do and the handwork it took to put them together.

Long post short: There are a lot of other pre-made rigs and automated rigging systems and even other animation packages but they all have rules. How you approach learning new things will greatly help or hinder your ability to adapt. You won't be able to change the vast majority of those automated rigging systems, you either find one that works best and learn to live within it's rules or you build your own.

sr3d

Mark Dygert said:

I say this because I was once in your place...

CAT is pretty decent and very flexible, but you do give up some freedom in order for the system to function, it's that way with all automated rigging solutions. There always have to be rules for a procedural motion system like that to work. 

It's nearly impossible to design an open rigging system that won't gimbal, has procedural motion, and works with clips, is customizable and works as everyone wants it to. At best you can redesign a custom rigging system to fit your needs, but everyone that wants to use it another way will bitch up a storm when the rules you create don't match what they want to do.

You can't please everyone. Those who choose rigging automation over creating a rig from scratch, don't have much room to complain, that's the trade off. CAT does a pretty good job of trying to rig a lot of very diverse creatures while letting you Frankenstein a rig to your needs but even then, there are rules you have to play by.

For max there isn't much because Biped and CAT are already in max. Biped is rock solid, production tested, has a lot of support for working with animation clips and transferring motion from one biped to another. The IK/FK at the same time will spoil you. It won't ever gimbal on you, because it works on Quaternion, but that won't let you slide X past Y and there has to be a key on every track, which I don't mind giving up, its a small price to pay for hours of cleaner animation with less headaches.

Besides most experienced animators won't use procedural motion unless it's for temporary, blocking purposes, then they throw it out and start animating. Most won't touch procedural motion, they will quickly hand key a few poses, use an existing cycle they did previously or they'll use mocap. So really procedural motion is an under used feature by most animators. It's really there for people who can't animate a walk cycle... which means they probably can't rig either so they should probable be thankful that someone even put a semi-robust system in place =P

For me personally, Biped and CAT spoiled me rotten. I have insanely high standards for custom rigs because of it and I mostly work in Maya now. I complained when I was learning to use them, because they didn't work like most rigs I had encountered. But once I got used to their workflow and was able to leverage the tools as intended, I came to appreciate what they could do and the handwork it took to put them together.

Long post short: There are a lot of other pre-made rigs and automated rigging systems and even other animation packages but they all have rules. How you approach learning new things will greatly help or hinder your ability to adapt. You won't be able to change the vast majority of those automated rigging systems, you either find one that works best and learn to live within it's rules or you build your own.

I'm currently live streaming @
 After carefully reading your response, I am going to try again and keep my goals small.  I think I'm going to allocate 2-3 months to crash coursing animation.

Does anyone know how to prevent the spine and neck from swaying left and right when rotating the hip on a cat rig? In other words, prevent the spine and neck from moving when rotating the hip.

Mark Dygert

When you rotate the hips on local Z or Y? You might be able to turn off or limit the influnace of some rotations for the spine by going into the hierarchy tab and having a peak at its options, but nope I don't think there is a way inside of CAT to get independent hip rotation that doesn't influence the rest of the hierarchy. Biped allows this kind of motion in the hips because the rotation for the hips doesn't drive the spine, the Center of Mass does.

Sadly the Biped preset for CAT doesn't mimic this functionality.

That's one of the concessions I was talking about, you give up independent hip rotation When you use CAT. That's what they chose to do, to get their procedural spine to work. You can switch the Spine to FK, but it will act like every other chain of bones and rotate the children.

With some extra rigging you can add joints and controllers to the hips, to duct tape on the functionality you're looking for, but that will operate outside  of the CAT features and make for a dirty hierarchy.

So what you might end up doing, is creating a "resulting" skeleton for your final skinned mesh/animation with a simplified hierarchy and constrain it to your hybrid CAT rig. A final resulting skeleton is very common in custom rigs, they often float/blend  between IK, FK and dynamic rigs. But going to that trouble just to get independent hip rotation seems like a lot of work.

sr3d

Mark Dygert said:

When you rotate the hips on local Z or Y? You might be able to turn off or limit the influnace of some rotations for the spine by going into the hierarchy tab and having a peak at its options, but nope I don't think there is a way inside of CAT to get independent hip rotation that doesn't influence the rest of the hierarchy. Biped allows this kind of motion in the hips because the rotation for the hips doesn't drive the spine, the Center of Mass does.

Sadly the Biped preset for CAT doesn't mimic this functionality.

That's one of the concessions I was talking about, you give up independent hip rotation When you use CAT. That's what they chose to do, to get their procedural spine to work. You can switch the Spine to FK, but it will act like every other chain of bones and rotate the children.

With some extra rigging you can add joints and controllers to the hips, to duct tape on the functionality you're looking for, but that will operate outside  of the CAT features and make for a dirty hierarchy.

So what you might end up doing, is creating a "resulting" skeleton for your final skinned mesh/animation with a simplified hierarchy and constrain it to your hybrid CAT rig. A final resulting skeleton is very common in custom rigs, they often float/blend  between IK, FK and dynamic rigs. But going to that trouble just to get independent hip rotation seems like a lot of work.

A lot of great info here, I appreciate it.

Can I ask you one more thing? You wouldn't happen to know how to bend the knee up by 45 degrees like this:



I cannot figure out how to just get the knee to bend up like that. I currently have to use the foot platform which causes undesired results during animation. 

I'm trying to just get the character to lift their knee back, that's it.