Something wrong here with Carrara IK

argus1000

I used to be able to handle IK pretty well in Carrara, buit no more.  Here is Victoria 4 with IK and Michael 5 with IK (with Faba's instructions). Now as soom as I move an IK target, with either figure, the bone doesn't move at all; instead, the figure deforms strangely. See pic. What am I doing wrong? Thanks.

3DAGE

Hi Argus :)

That looks like the constraints are turned off for the scene,. ..

You can swith it on/off, using the little icons at the top of the scene window,. where the view options are..

pic :)

 

Also,.

If you use the File menu to Open, or Import V4 or M4 (CR2) from your runtime library,. there's an option to add ik targets to the figure,.and some other useful options.

 

argus1000

Thanks so much, 3dage. I've spent hours trying to fix this problem. Without you and your knowledge, I would've wasted many more hours.

argus1000

I have finally given up with the whole Carrara IK solver. It is so archaic as to be unworkable. Let's say you have a mocap of a character walking to and  trying to open a locked door. His hand has to be steady on the handle during the time he tries to open the door. That means you have to have a target helper in the handle, which is parented with IK to his hand. That hand has to be LOCKED to the handle. Otherwise, your hand is going to shake a little all over the place. And that only during the time he holds the handle. It might be possible to get the Carrara IK solver to do that for the whole clip, maybe, if you like self-punishment, but not for only the time he holds the handle. It becomes quite messy with the Carara IK solver. Quite messy.

So I tried to do my IK work in iClone. They have an IK solver which is a better and easier to use. It is modeled on the Maya Human IK. The IK solver is activated with a function called "Reach target". I had no problems there. It was a cinch and worked like a dream. So I imported my mocap in iClone,  did my IK work there, and then exported  the result back in Carrara... and I am happy ever since.

DUDU

Hi Argus !

Have you ever seen this: http://www.sharecg.com/v/83030/browse/5/3D-Model/DanceForms-Models-for-Gen4-Genesis-and-Genesis-2

I often use .bvh files and never a target helper, I delete the wrong keyframes and make my own animation for this part (with manipulators).

argus1000

DUDU said:

Have you ever seen this: http://www.sharecg.com/v/83030/browse/5/3D-Model/DanceForms-Models-for-Gen4-Genesis-and-Genesis-2

I don't know how to handle LFS files...

 

DUDU

Look the video here: http://www.bond3d.byethost18.com/index.php?topic=333.msg1941#msg1941

argus1000

Hi Dudu,

This video is showing me another way to get retarget mocaps and import them into Carrara, since Carrara is not very good at importing them directly. But I already have a way. I make my own mocaps and import them already retargeted into Daz Studio. From there, I am able  import them faultlessly into Carrara. The problem I have has specifically to do with Carrara IK solver. I want to be able to LOCK the character's hand to a specific object (in this cas a handle) for a specific amount of time. Thanks for your advice anyway.

3DAGE

The problem is that you have two things happening,. the mocap info (for the arm) is giving per frame animation data,. the IK target Cannot overwrite that.

IK is not a pinning method,. and it should be used to help create animation,. rather than to correct existing animation

Delete the mocap animation keys for the entire arm , or edit those keys. to smooth out the animation,.

If you delete the keys for the arm,. then the IK target will work correctly.

Smoothing the animation from any Motion capture system is a standard and essential step,. whether it's home made mocap or professional multicam.

also try increasing the mocap frame rate ,. I normally use either 60 or 120 , and I still need to edit the results to correct some parts.

Poser is useful to do the editing, since it has a nice graph editor, and the final data can be saved as a Pose (PZ2)

Hope it helps

 

 

argus1000

I appreciate your advice, 3dage. However, if I delete the keyframes for the arms, the hand is still going to shake slightly, due to the movements of the chest and hips. So that will not work. If I edit the keys, there is no way I can edit them enough to get a really stable animation, where the hand is locked to the door handle. As far as IK not being a pinning method, is is just that  in iClone; it pins or locks the hand movements very well there. So that's the reason I say Carrara IK is archaic. Sorry.

3DAGE

Yes, I should have been clearer,. my bad,.  you need to delete all of the keys for the entire arm, ..that includes everything from the shoulder to the fingers,. all gone,.

you may be able to keep the finger animation,.. if those have been captured correctly,. those shouldn't effect the position of the rest of the arm.

Then it should be relatively simple to hand animate the arm/hand, reaching for the door handle. (you may need to create animation keys for each frame on some parts),. eg where the hand is holding the door handle. or use an IK target,. since the arm doesn't have any keys,. the IK target should work correctly

in editing the mocap keys,. you should be able to reduce the keys for the arm down to just a few (main key frames) ,. bearing in mind that the "important" part,. where the hand is in contact with the handle,. would either need more keys,. or an ik target,.

if there is still body motion effecting the hand at that point, then you need to consider the same type of keyframe reduction on the body.

If the figure is simply approaching a door and opening it,. then that body motion should be pretty smooth,. ..it's not as if the figure is dancing to music while opening the door

If it is that erratic,. then you need to look at refining the mocap data in and out,. eg: frame rate of capture and editing the results

Ideally IK should be used on an un-animated figure, to animate that figure. rather than using FK, or hand posing, to create the keyframes.

IK can be used to Hold the position of the object,. but it was never intended to be used as a method of compensating for erratic motion capture data. it doesn't overwrite existing FK data

 

 

argus1000

This is what I was after. I coudn't do it with Carrara. I had to go through iClone. The character's hand is steady enough on the handle, but it is locked.

3DAGE

Very nice Argus :)

that's smoother than I expected.

whatever works .. works :)