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Roger

fan bone not following geometry bones?

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Hello

 

I am fixing some of my rigging on my penguin character, and am having to adjust the bones. The fan bones for 2 of the geometry bones in the flipper are not following either bone when moving the geometry bones, I am having to manually reposition them. They don't seem to have an option for "Attached to parent". Am I doing something wrong, or is this normal?

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Are the fan bone constraints set up in a pose or action? If a pose, is the pose turned ON?

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If you have a bone chain like, for example, upper arm bone and lower arm bone. And the fan bone is placed at the junction of upper arm and lower arm (for the elbow), it should be a child of the upper arm bone. In other words, a fan bone should generally (in most cases) be a child of the bone which is higher in the chain. Fan bones generally are not supposed to be attached to a parent bone. When a bone is a child of another bone, it will follow that bone even if it is not attached to it.

 

Look in your Bones folder and make sure your fan bones are children of the geometry bones you are moving.

 

If you mean that the fan bones are not *rotating* with the proper geometry bones, make sure the constraints pose for the fan bones is turned on, like mark said. This is assuming you have set "Orient Like" constraints for your fan bones. If you have not created these constraints, they will definitely not rotate like you want them to.

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I seem to have fixed what was up with the flippers - they follow the torso correctly now when its rotated (bending forward). The flippers are now children of the torso bone - before I had the constrained with an "orient like" constraint.

 

However - when I bend the penguin from side to side (think side stretches ) the flippers intersect w/ the body instead of staying apart from the body. I wonder if I screwed something up that was working before.

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Do they need to be constrained to the torso bone as well as being children of it, in order to follow correctly? I suppose I can try that, I can always change it.

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Do they need to be constrained to the torso bone as well as being children of it, in order to follow correctly? I suppose I can try that, I can always change it.

 

What you show there is not unexpected, given the proportions of the character. Chubby characters are very challenging to rig.

 

One solution would be to put the first spline ring of the arm on a bone that is a child of the upper arm bone and originates from the same point, but is constrained to maintain its orientation with the middle spine bone. (However the same thing on the other side may look odd... a rotation limit constraint may be needed)

 

Also spreading the bend of the spine among all three spine bones rather than just the op will reduce the degree to which the wing is intersecting the middle of the body.

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Do they need to be constrained to the torso bone as well as being children of it, in order to follow correctly? I suppose I can try that, I can always change it.

 

What you show there is not unexpected, given the proportions of the character. Chubby characters are very challenging to rig.

 

One solution would be to put the first spline ring of the arm on a bone that is a child of the upper arm bone and originates from the same point, but is constrained to maintain its orientation with the middle spine bone. (However the same thing on the other side may look odd... a rotation limit constraint may be needed)

 

Also spreading the bend of the spine among all three spine bones rather than just the op will reduce the degree to which the wing is intersecting the middle of the body.

 

Ok - I see what you are saying about spreading the bend out - that seems to work. I may just leave it that way for now and use that as a workaround.

I finished making the changes to the cp weighting that you recommended, but still notice slight (much better than before) bulges at the waist when bending.

For instance, there is still a bit of a bulge on the cp ring that is just above the flippers when bending the penguin forward, spreading the bend over all the spine bones.

Do you think I need to worry about it, or would you recommend experimenting w/ different weights or maybe putting additional fan bones in?

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Do you think I need to worry about it, or would you recommend experimenting w/ different weights or maybe putting additional fan bones in?

 

All of the above. ;)

 

Rigging is a journey of testing things out and deciding how much punishment something is really going to have to take.

 

A while ago I rigged a face for an animator's character and I made it so the mouth would still look good even with what I regarded as a bigger smile than anyone would ever want to do.

 

But when he saw that it still worked with the smile that big he wanted to make it smile even bigger...

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:D heh - I think I will get it to a state where its ok to do some test animations, then maybe refine it later on. I'm starting to get a bit tired of cp weighting, but I think I understand it a bit better now.

 

Is there a convention or rule as to where a bone should be on a spline ring? Should it be right in the middle, or should the end of the bone be at the start of the ring?

I admit when I was putting the bones in I was guessing a bit.

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Is there a convention or rule as to where a bone should be on a spline ring? Should it be right in the middle, or should the end of the bone be at the start of the ring?

 

It's more where should a spline ring be on a bone.

 

A spline ring in the middle of a bone is least likely to need to be weighted to anything besides that one bone. The closer it is to a joint, the more likely it may need some fan or weighting solution. Maybe.

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Is there a convention or rule as to where a bone should be on a spline ring? Should it be right in the middle, or should the end of the bone be at the start of the ring?

 

It's more where should a spline ring be on a bone.

 

A spline ring in the middle of a bone is least likely to need to be weighted to anything besides that one bone. The closer it is to a joint, the more likely it may need some fan or weighting solution. Maybe.

 

So would yanking my existing skeleton and redoing it such that the spline rings fall across the middle of a bone, if possible? That way less rigging is required? I guess I'll need to play around w/ it and see what happens.

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So would yanking my existing skeleton and redoing it such that the spline rings fall across the middle of a bone, if possible? That way less rigging is required? I guess I'll need to play around w/ it and see what happens.

 

 

 

Sometimes (many times) you need a spline ring at a joint to get the shape you want. If so, so be it. Just be aware that those will need some weighting or fan solution.

 

You might look at things and ask can I get the shape I want with the splines in a more convenient spot?

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I am working on fixing the legs now, andI have the crotch fixed and the CP weighting fixed so that when you raise the legs ( like for a split) the side of the penguin doesn't bunch up.

 

I am having a hard time fixing the way the legs bend at the "knee" of the penguin - I tried adding a fan bone in there and then weighting it 50 on the fan bone, and 25 on the femur and the thigh. That seemed to fix the way the front part of the leg bends at the knee, but the back is still looking wierd. I am not sure I can fix this w/ just CP weighting - hence the fan bone. But it didn't really seem to do anything by itself, so I changed the weightings.

 

Problem is when I select the spline rings to adjust CP weights, there is the potential for screwing up the weighting of the crotch. I can only select part of the ring to adjust the weighting. I feel like I'm missing something that should be obvious to me.

penguin_legs_partly_fixed.jpg

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Currently I have a fan bone between the thigh and the femur. Its weighted 60 percent to the femur and 40 percent to the fan bone.

 

I am wondering if I should add the CP's on the back of the crotch to that ring I am trying to weight, to see if I can get them to move a little better w/o the butt or the thigh looking like its caving in.

 

I also wonder if perhaps I'm making too big a deal out of this, since penguins don't have a huge range of motion for their legs anyway?

back_of_thigh.jpg

back_of_thigh_2.jpg

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Weighting hips and shoulders is always tricky. It just takes a lot of practice, and trial and error. If the front of the crotch works OK, then select only the back CPs and hit the lock button, so you don't accidentally change the weights on those. CPs in the butt are usually weighted to the pelvis, (sometines lower back), hip fan, and thigh to varying degrees - it just depends on the mesh.

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Weighting hips and shoulders is always tricky. It just takes a lot of practice, and trial and error. If the front of the crotch works OK, then select only the back CPs and hit the lock button, so you don't accidentally change the weights on those. CPs in the butt are usually weighted to the pelvis, (sometines lower back), hip fan, and thigh to varying degrees - it just depends on the mesh.

 

 

I guess I am just going to have to keep messing with it and trying things to see what works and what doesn't. If I select the back parts of the crotch to try and fix the weighting, its not going to affect the crotch weighting I've already done, will it? Or does AM just consider that a whole new entity?

 

I was wondering if I should stitch more detail into the back of the leg, to alleviate creasing there, or if that would just make things worse.

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Currently I have a fan bone between the thigh and the femur. Its weighted 60 percent to the femur and 40 percent to the fan bone.

 

you really mean "40% to the calf bone", right?

 

I am wondering if I should add the CP's on the back of the crotch to that ring I am trying to weight, to see if I can get them to move a little better w/o the butt or the thigh looking like its caving in.

 

I also wonder if perhaps I'm making too big a deal out of this, since penguins don't have a huge range of motion for their legs anyway?

 

I'd make the big rings that form that knee protrusion stay with the thigh more and less with the calf.

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Oops, looking at the pictures, I assumed you were working on the hips ... but that is the knee? You can save yourself some grief and move the knee down to a more natural position (about half way down where the calf is now). Not sure if it is anatomically correct for a penguin, but it will make weighting the knee a whole lot easier. Remember to place three horizontal spline rings where you want your knee (or any joint that bends, such as elbow, hips shoulders etc). But you will still have to go through all this when you weight the hips ...

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Oops, looking at the pictures, I assumed you were working on the hips ... but that is the knee? You can save yourself some grief and move the knee down to a more natural position (about half way down where the calf is now). Not sure if it is anatomically correct for a penguin, but it will make weighting the knee a whole lot easier. Remember to place three horizontal spline rings where you want your knee (or any joint that bends, such as elbow, hips shoulders etc). But you will still have to go through all this when you weight the hips ...

 

Well - the first picture I posted is showing the hips more, w/ the legs splayed out like that. The other 2 pics are meant to show the remaining problems I am having when moving the legs.

 

I've watched a few videos online of penguins walking for reference, and its more of a waddle - they have a very stiff-legged gait, and the knees are actually hidden.

I wonder if it might be better to just have one leg bone, and animate with a very limited range of motion - its not going to be picking its leg up very far, after all.

 

I'm not even sure where I would begin with smart skin. Do you adjust the skin of the model at the different points of a motion?

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I'm not even sure where I would begin with smart skin. Do you adjust the skin of the model at the different points of a motion?

 

Yes. However adjusting the mesh so it appears consistent from one key to the next is a challenge.

 

Make SmartSkin your last resort. For the limited motion a penguin does, CP weighting or fan bones should do well.

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I'm going over the Zundel tutorials on rigging again, it looks like when he is making fan bones for his example, he is not assigning or weighting them to any CPs.

Is this normal, or must fan bones be weighted to CPs as well? I am not sure how its affecting the geometry if he is not assigning it to anything.

 

I'm still working on the legs, I don't think i am going to have the lower legs bend very much, I may use constraints to limit their range of motion.

 

Should I be using the whole ring around the knee in my CP weighting, or just a portion of it? That part of the leg shares points with the crotch I think.

I am concerned that this will screw up the weighting in the crotch.

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Another thing I noticed in the Zundel tutorials - when he is adding the spine bones in his Will model, he places the bone exactly in the middle of the ring, and he has a spine bone for each ring - the spine bones do not touch each other, as they do in my rig. Maybe this is why I had so many problems in rigging the penguin originally.

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I'm going over the Zundel tutorials on rigging again, it looks like when he is making fan bones for his example, he is not assigning or weighting them to any CPs.

Is this normal, or must fan bones be weighted to CPs as well? I am not sure how its affecting the geometry if he is not assigning it to anything.

 

I don't know what you mean. Bones are never weighted to CPs. CPs are weighted to bones.

 

I've not seen his tutorial so i dont' know what he may be abbreviating.

I'm still working on the legs, I don't think i am going to have the lower legs bend very much, I may use constraints to limit their range of motion.
You shouldn't use a constraint to limit motion for that. If you want the legs to not bend much, pose them not bent much.

 

Should I be using the whole ring around the knee in my CP weighting, or just a portion of it? That part of the leg shares points with the crotch I think.

I am concerned that this will screw up the weighting in the crotch.

 

Every CP has it's own list of bones it's weighted to. You can see this when you select a CP and do "Edit CP weights"

 

The weighs of one CP won't affect the weights of another PC, unless you are editing them both together.

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Another thing I noticed in the Zundel tutorials -

I haven't seen his tutorial, so i don't' know what this refers to exactly.

 

 

 

when he is adding the spine bones in his Will model, he places the bone exactly in the middle of the ring,

In a human the spine is closer to the back than the front. In a cartoon character it may not matter to be that exact. this is not a huge issue. It all depends on where you want the center of rotation to be.

 

Note that when a human bends back the torso is stretched, when a human bends forward the torso is compressed. Why? Because the spine is closer to the back than the front.

 

 

 

 

and he has a spine bone for each ring - the spine bones do not touch each other, as they do in my rig.

 

Not sure what you mean

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I'm going over the Zundel tutorials on rigging again, it looks like when he is making fan bones for his example, he is not assigning or weighting them to any CPs.

Is this normal, or must fan bones be weighted to CPs as well? I am not sure how its affecting the geometry if he is not assigning it to anything.

 

I don't know what you mean. Bones are never weighted to CPs. CPs are weighted to bones.

 

I've not seen his tutorial so i dont' know what he may be abbreviating.

I'm still working on the legs, I don't think i am going to have the lower legs bend very much, I may use constraints to limit their range of motion.
You shouldn't use a constraint to limit motion for that. If you want the legs to not bend much, pose them not bent much.

 

Should I be using the whole ring around the knee in my CP weighting, or just a portion of it? That part of the leg shares points with the crotch I think.

I am concerned that this will screw up the weighting in the crotch.

 

Every CP has it's own list of bones it's weighted to. You can see this when you select a CP and do "Edit CP weights"

 

The weighs of one CP won't affect the weights of another PC, unless you are editing them both together.

 

I misspoke - meant to say there were no CPs weighted to his fan bones. I guess my brain is fried from working on this.

 

So a CP can be weighted to more than one bone, if necessary?

 

I am going to stick with the rig I have - I have pretty much everything working I just need to ge the legs worked out.

I am NOT looking forward to rigging the other main character, I have a feeling its gonna be a nightmare. I'm going to use either the 2008 or TSM2 rig for it.

 

Thanks for your help, sorry if some of my posts have been unclear - guess I am typing faster than I'm thinking.

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Another thing I noticed in the Zundel tutorials - when he is adding the spine bones in his Will model, he places the bone exactly in the middle of the ring, and he has a spine bone for each ring - the spine bones do not touch each other, as they do in my rig. Maybe this is why I had so many problems in rigging the penguin originally.

 

The spine geometry bones in Barry's rig are not connected (they are parented like a chain of bones though) and he has one for each ring of the torso, but, there are fewer spine control bones that are connected (1:08:00 of the tutorial).

 

As Robert said, the spine is generally more toward the back of the character, but, depending on the character, doesn't have to be that way.

 

You don't need a geometry bone for each spline ring, CP Weighting can take care of the blending between bones for the most part. You can get away with a three bone spine and still get good spine movement.

 

I'm going over the Zundel tutorials on rigging again, it looks like when he is making fan bones for his example, he is not assigning or weighting them to any CPs. Is this normal, or must fan bones be weighted to CPs as well? I am not sure how its affecting the geometry if he is not assigning it to anything.

 

When Barry is putting in the bones he names them according to how he is going to weight them later...so, he puts them in first and then goes back later to assign them to bones.

 

Hope that helps, Roger.

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So a CP can be weighted to more than one bone, if necessary?

 

yes. 50/50... 60/40... 27/73... whatever you want. You can weight it to as many bones as you want... 25/25/50... 14/12/34/5/35... anything really. most CPs are weighted to just one or two bones. you can add a bone to a CPs list with the add bone menu at the bottom of Edit CP weights.

 

Weighting can often eliminate the need for a fan bone.

 

I think Someone has already done a tut on the CP weight editor. Look for that.

 

V16 has changed the editor a bit.

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Ok - this makes more sense now. I was worried when I was weighting the CPs for the knee on my penguin that it was going to affect CP weights that I had already assigned.

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Well - I think I figured out what I was doing wrong. I was using the right weights, but weighting the CPs on the wrong damn spline ring to the bones that make up the leg. I have no clue how I screwed that up.

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OK - it looks better now. I have the CPs that make up that spline ring (but not the ones in the crotch that are on that ring) weighted 50 to the calf and 50 to the thigh, and it looks better. I'm going to try a different ratio and see if it looks better weighted more towards the calf.

 

I tried including some of the points on the crotch but ran into problems getting errors about "CP such and such is weighted more than once".

 

The area circled in red and on the back of the leg in the first pic is still giving me trouble. This may be as good as its gonna get unless I use smart skin. Maybe I'll just avoid close-ups and shoot above the waist, mostly.

 

Thanks everyone.

progress1.jpg

progress_2.jpg

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I wonder if stitching in more geometry would help with the way the leg looks when bending at the knee? It seems like that could be part of the problem - maybe there are not enough patches there to interpolate the bend smoothly (without using smart skin).

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