Locking parts of a pose while animating.
Hermit Crab
Posts: 839
Hi folks,
Having spent a good part of today reading the manual and trying things out, I'm still stuck with a problem in animating.
I've been trying to keep a figure's feet on a particular spot while trying to make it stand up. If I select the hip to raise the body up and lean forward, the legs and feet follow on. In other software, the feet can be locked on the spot and dragging on the hip allows the legs to straighten.
I tried an IK target and had a little success but wondered whether there was a better 'tried and tested' method? I would have liked to be able to move the IK target and have the foot follow it around. (I'm using Genesis2 - maybe the function I want would only be possible on a home-made figure?)
While I'm asking, there doesn't seem to be any way just to freeze an object in the scene?
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Here's a little animation I did long ago showing a simple IK rig on a character, with feet placed firmly on the ground during the animation.
Not sure specifically what you're asking, could you be more specific?
Also, what do you mean by "freeze" ? Under the Motion tab there is a "Constraint" selection where you can "Lock" an object. Maybe that will do what you want?
Hi Joe,
Thanks for the reply and for the link to your video.
In the video, your character is standing and bends his knees until he almost touches his own heels. Then he straightens up again and, throughout this motion, his feet have remained on the same spot.
I could do this easily in Poser because, by default, the figure's feet are 'frozen' on the spot. I would simply select the hip (or whatever bone is the central one) and pull the figure downwards. The feet stay on the same spot and the knees are forced to bend. If I pull upwards high enough, the figure's feet do raise from the ground but they are still drawn to the spot they were standing on (if I move upwards and sideways, say).
What I've been trying to do in Carrara is take a figure sitting on a rock, legs dangling over the edge. I want her to stand up. So far I've animated the figure swinging round with the legs simultaneously being drawn up to begin standing up from the flat rock she was sitting on. At the point where the figure has swung round she needs to lean forward, put her weight onto her feet and begin to stand up. It would be great to start this part of the animation by having both feet fixed in place at that point. Then I could select the hip and pull upwards - just as I could in Poser. The legs would straighten up as yours did in the video.
Instead, when I raise the figure by the hip bone, the whole figure rises with the legs still bent - as would be expected unless the feet could be fixed in place.
The pre-built nature of DAZ characters may be the problem in setting up a new IK chain. I tried and it worked poorly.
As for locking from the motion tab:
The motion tab has different sections to open up: Constraint; Translation; Transform, etc. None of them seem very intuitive to me at first sight. In conjunction with the manual, they do make a lot more sense but I still can't see a simple way to freeze parts of a scene. The 'Lock' tick box only seems to apply to certain types of constraint - if I remember correctly - my brain is wasted nowadays.
If you select part of DAZ G2 figure and look at the Translation section of the Motion Tab, there are 6 padlocks, 3 odd symbols (which toggle on and off) and 12 tick-boxes to play with. By playing with these, I could get a shin-bone to freeze but I thought that there may be a tried and tested better method.
I appreciate your help and any further help but if there is no quick answer, I would hate anyone to go to a lot of trouble on my account. Maybe other people would use NLA clips - about which I know next to nothing!
Regards
IK and target helper objects are the way to go to keep feet in place or hands locked down. Just remember that the feet or hands that have IK enabled are still bound by constraints, so pulling or pushing a limb way out of position will effect how well it stays locked down. Fortunately there are ways around this, such as changing the constraint method or limits.
In these two tests, I locked the foot down to the ground by using IK tracking and a target helper object. The first video uses the standard constraint that loaded with V4. Notice the foot not staying completely in place?
For the second video, I changed the constraint on the foot to, Ball Joint. Now there is no shifting of the foot. Keep in mind that each situation is unique, so my solution may not be the best for your scene.
We may need a little more information about "freezing" a figure. Do you mean that you want to make a previously animated figure stop moving for awhile, and then start later in the scene? If so, then it is possible that you will want to try the Discrete Tweener. If you need to know how to change tweener types, let us know.
Thanks to you also, Evilproducer, for your assistance. I've just replied to JoeMamma2000 with more information on what I'm trying to do.
From what you've said and shown and from what Joe has shown I think that I'm simply failing to try hard enough.
I did use the IK Chain tool (on the left, under the other manipulators) and applied it to one of the foot. I could then 'attach' it to a cube palce in the scene.
But when I tried moving the cube, I thought it would cause the foot (and the rest of the leg) to follow. I thought that I could push the cube upwards and that would cause the knee to bend, for example. Similarly, I thought I could place the cube on the flat rock and the foot would stay there until the cube was moved.
Your examples show that I seem to be on the right track and might need to re-read the manual and try harder!
Evil,
The question about freezing an object in a scene just arose while I was researching this. I just wondered whether scene elements could be fixed in place somehow. The idea is to prevent mis-selecting while trying to animate. I know that I can right-click and select from a pop-up list but it sometimes happens that I'll pick up the rock the figure is sitting on rather than the part of the figure I meant to select.
I was using Genesis2 female. I had played with some of the settings in the motion tab during the same session and may have lost track of what to undo by the time I got round to the cube!
I tried a couple of times and probably got Carrara as well as myself confused!
When I moved the cube, both legs would move sometimes, swinging from the pelvis. If I pulled the whole figure forward from the cube, the leg would stretch out and stay behind (at one time) but if I then moved the cube forward, the leg stayed where it was.
I think I mixed myself and Carrara up a little and need to start over now that you've confirmed this as the way to go.
Sorry to be so vague. I'll try again tomorrow - or should I say later as it's almost 2 am!
I don't have access to C8.5 at the moment, so the screen shot is from C7.2 Pro and uses a V4. If you are using a pre-rigged figure, such as a Genesis 2, it should already have the IK modifier. You just need to enable it and select the object to track.
You'll notice from the screen cap that there is also an IK terminator modifier as well. This is for the toes I believe. From my limited experience with Genesis and Genesis 2 IK, it was a little different than what I was used to from the earlier figures. I found it helpful for instance to add the IK Terminator to the shoulder joints (name may be wrong) otherwise when I pulled the hand, the whole torso moved.
Hi Marcus
In a Prebuilt figure,.the limbs would normally already have the IK set up, so what you need to do is add a helper (Target helper Object) and set that as the Target for the Foot or Hand to follow,. Then the Target heloper object can be used to Move the limb. The limb will always track the target. so if the Figure's Hip is moved, then the Foot / Hand (or whatever body part you've assigned) will track the Target helper Object,.
In a Carrara built Figure, you'd use the IK chain tool to add the IK for the Limb,.(this alo creates a litte Cube helper object) which can be moved in the same way as the default X shaped target helper object.
By moving the target helper objects,. you animate the figure.
You can create multiple target helper objects , colour them differently, (left and right for example) and scale them to suit,.
You can also add limits or constraints to target helpers, so if cannot go Higher or lower than a set height or left/right etc.
For Genesis Figures,. Faba built a set of Drag'n'drop Modifiers and Helpers to work around posing and animating issues with genesis in Carrara,.
they are still available freely on ShareCG.
http://www.sharecg.com/fabaone
Sorry Evilporoducer, it looks like your post was sent last night as I was giving up for the day. Unfortunately, one of your images doesn't show in my browser but I recognize the other as the feature I used to assign a cube as a helper.
Thanks very much also 3DAGE for your very helpful post which agrees with Evilproducer's advice. Thanks also for the link - I think it's high time I joined that site (forum browsing beats trying to actually DO something!)
I think that what I might have done yesterday is confuse things by trying to use the IK Chain tool on a figure already equipped with IK chains. Maybe I attached the helper to the wrong one - I'm sure to have used the tool wrongly due to haste.
So thanks again to all three who helped me. In passing, it was good to re-visit the manual. I'm at a stage where I can add to the things I already half-know. Also, it is good for getting a renewed respect for Carrara.
So, back to the fray ... later!
Ah, I see.
I'm not on top form these days am I?
I see that the thread on the number of DAZ purchases Carrara users make has touched on the topic of animation. I'm looking forward to any threads on this. Somewhere on an external disk I have a little biped I made where the blocks making up the body were put into a parent-child hierarchy. I moved the hot-points of each part so that the hot-point for the thigh was at the hip and the hot-point for the shin was at the knee... and so on...
It's a great little tool for trying out simplified figure animation. The DAZ figures have so many parts - the hierarchy is huge and much of it gets repeated for clothes and hair.
I will go back later to the scene I was working on yesterday armed with what you've helped me with but I'm sure I'll need to re-read it until it sinks in!
If it helps, I do find it useful to get my target helpers and figure posed close to where I want them at the beginning of the timeline before I enable the tracking options. In this video, I wanted to use IK tracking and various modifiers to automate a V4 riding a bike. I put V4 on the bike, posed her and then worked on parenting target helpers to the pedals and handle bars, set up rotation modifiers for the wheels and sprockets, etc. before I enabled the tracking.
I did keyframe some torso animation and head animation, but otherwise it is completely automated. I also changed the constraints on the hands to ball joint to avoid slipping and twitching as limits were approached, but I found the standard constraints on the feet worked best.
Excellent results!
Your work shows that understanding the different contraints helps with the fine details. I've a lot to get a better grasp of.
The rotation modifier is useful for so many items and there are some other great modifiers to experiment with also.
PS It's interesting that V4 cycles to work just like many other ordinary people. I suppose she just leaves the sword and shield overnight with one of the temple caretakers.
I'm interested in this too. Recently I wanted to sway a figure leftward, keeping the feet in place. Also wanted to pose a hand on a building column. I played around with IK Helpers, Target Objects and and IK Chain tool. I admit, I got lost.
When I added a Target Object to a shoulder, the shoulder and target both jumped upwards about 6" on activation?? I assumed when you "activated" it would retain its present position and change when you moved the Target Object. Didn't in my case. I even moved the Target Object to the exact same location as the shoulder, didn't make any difference. It always jumped upward, deforming the figure.
I'm used to using one of those little pose helper tools, where you can Pin and Unpin joints one click before you animate. Not having that in Carrara, what I'd love to see is a simple solution set for scenarios like...
* To move the hip, leaving feet locked in place ... do this
* To move arms without moving shoulder
* To stretch arms out with shoulder and back following (feet locked)
Related: is there a way to easily enable/disable IK Terminators as you pose? AFAIK the only way to do the things I mentioned is to enable/disable IK Terminators. I find it pretty awkward digging into the bone tree to get to them to turn em on and off.
Many thanks for any suggestions!
- Don
And that's your problem right there...
The basic concept of an IK chain is this:
When a human reaches for a jar on the shelf, his hand moves directly to the jar, and the forearm and shoulder and upper torso follow along. The hand moves to the target object (the jar), and the arm and all connected stuff move along.
If this didn't happen, we would have to plan something like this:
"Okay, so I first need to rotate my torso a bit toward the jar, then move my shoulder up a bit so my elbow is kinda pointing at the jar, then rotate my forearm out to place my hand close to the jar, then rotate and open my hand so it can grasp".
Not fun.
That's why God created IK. You place the target, and your body obliges. Without IK, you're left with FK (forward kinematics), where you start planning in a forward manner like I described (torso, then shoulder, etc.)
The purpose of an IK goal is to provide a goal object so the IK can do its magic. In the example I mentioned, you place the IK goal at the jar on the shelf and your body follows. But the IK goal is a goal for the hand object, just like in real life. You go to the end of the chain (shoulder, forearm, HAND) and set the IK goal as the goal object.
If you set it for the shoulder your character might explode.
And some more basic concepts...
Generally, you configure your character this way:
Once you have those set up, and I believe at least the leg IK chains come preconfigured with the V4/M4 and other characters, you should be good to go. The hands and feet should stay locked to the goal objects as you move the hip.
Also, keep in mind that just because IK is pretty awesome and useful, you don't always want or need to use it. In fact, sometimes the app you're using has an IK implementation that, in certain circumstances, gives you fits and frustrations, so you're better off just disabling and doing FK.
Here's a simple demo video I did for a non-Carrara/DAZ person recently on a different subject, but in this case I used IK for the feet, but no IK for the arms. Actually, I use FK quite often because, being an automated response, IK might not give you the expression and movement you want. Yeah, it gets you there, but sometimes you want some subtlety and nuance that an automated IK doesn't provide.
http://youtu.be/_SEgsDmkB7E
One procedure I use to setting up IK on, say, a V4 is this:
At this point you should be all set. Move the character's hip bone down (-Z direction) and it should look like this.
Sorry Marcus, I just realized I missed your original posts here...completely...
Anyway I'll review them now and try to respond. Sorry.
Marcus, I'm still trying to process what you're asking about. But I think with what's been discussed so far we should be on the same page as far as setting up your rig.
So now at this point we'll do it step by step. You can get to your starting point of the girl sitting on the flat rock by merely moving your foot goals towards the front of the girl, and move her hip down so she's sitting. And her hand goals to get her arms to her side.
There should be no problems at this point. The feet should stick to the IK goals like glue. Most apps allow you to adjust the "strength" of the glue, like you alluded to, but I dont' recall if you can do that with Carrara. But in this case you shouldn't need to.
Now from this point you mentioned (I think...) that you want her to turn and raise her legs to stand up correct?
Now for me, the first step would be rotate her hip so she's positioned something like below
And that raises one of the first issues that I encounter which causes me to modify the rig setup I described. Often the knees (and elbows for that matter) tend to react in a way that you can't really control directly in IK. In this case if you want her to look more, well, "ladylike", you need to augment the rig with some additional targets that you can manipulate to control the knees.
And those are generally two additional Target Helper null objects placed in front of the knees, and assigned as goals for the thigh bone. But this only works if you already have foot goals.
Now, not knowing exactly how you want her to orient herself to in a position to stand, assuming she needs to bring her feet up to waist level, i'm not sure how you would do the animation from this point.
But to get more control over the knees, what I do (It's been a while since I did this in Carrara, so it's a foggy memory...but the concept is the important thing) is to add a Target helper for the knee, do the same "Align" to position it at the knee (actually I think it's the Shin hotpoint...), and set the Thigh bone to "Point At" that null.
And when you're done it looks like this
And if you parent that to the corresponding foot goal, it will follow along as you move the foot goal. Then just translate (move) the knee goal however you want to control the knees.
Keep in mind that it will be a contest between the foot goal and knee goal, so you'll have to balance them as you animate.
And here's my guess at her next move in order to stand up, though I'm honestly not sure how she's gonna do it gracefully without holding on to something.
But in any case, she's got knee goals and foot goals, and its just a matter or arranging those how you want. Or just forgetting IK altogether and do it manually with FK.
And in a side note, this is one of the times i REALLY wish Carrara had some way of just pulling out those few goals/bones you want to work on and making a simple control panel on your interface so you don't have to constantly scroll thru a bunch of stuff in the instances tab. Arrrrggghhh.....
Oh, and I also WISH that Carrara had a simpler, once click method to move one object to the location of another, rather than that ridiculous "Align" which requires 7 clicks just to co-locate two objects. And you always have to remember to click the "To" object first....Arrggghhh....
Sorry, just a little pent up frustration in Carrara land.
And for anyone interested in details of rigging a character for more realistic animations.
Long ago I posted a video showing a guy squatting and then raising back up, then moving side-to-side. For those detail-oriented folks, you might notice something strange in how he squats. Notice his feet and ankles when he squats down....it is totally unrealistic. As I recall (it's been awhile) I cheated. In fact, if you try to reproduce that motion yourself, you'll see that if you squat like that your ankles just don't bend that much, and at some point your feet don't stay planted flat on the ground. Instead, when you reach the limit of ankle rotation, you end up raising your heel so that you're squatting on your toes. That's how it really works. I suspect I disabled the rotation constrains to make it look okay with minimal work.
But in fact, when real animators do stuff like this they make more detailed rigs. In fact, they might have a fairly detailed foot rig, using expressions and other tools, which automatically rotate the toes and put the character on the balls of his feet when necessary. Same with the hands. Often there are very detailed, expression-driven rigs which make fairly complicated stuff like this automated, and accessed with only a slider so it's quite easy.
With Carrara, if you want this detail, you need to do a lot of it manually, Yeah, it can be done, but just not as easily.
I was able to get some success in making some toe goals, which keep the toes planted flat while allowing the ankle to raise when it reaches its limit.
I added two nulls and did a "Point At" for each toe bone. Unfortunately "Point At" is one of those post-calculated tools in Carrara so you don't see realtime update until you finish your motion and release the mouse button. But it can address the need to keep the toes working realistically.
Awesome... thank you!
So sounds like I don't need IK Helpers then, which if I got this right, only appear if you use the IK Chain tool.
The one other thing is... roughing out most of the pose with IK, then going back to FK. Do you just disable the Target Helpers via the bone's Modifiers property to put in the final tweaks with FK?
Thanks again
- Don