RE: the Cycle thing

[JM Khayat - PÏNKA <jmkhayat(at)pinka-prod.com>]

Well, in our IK/FK case, it works ok because when IK was selected to drive the skeleton, the effector of the bone chain follows linearly the ik goal, and when FK was selected, the ik goal follows the rotation of the bone.

It’s a win/win situation ;)

 

>I never used it in production but it should be ok as it does nothing special on the rig.
But use it only for translations. For rotations it shouldn't give expected results. You can rotate the constraining object on a frame and see the constrained object moving
in a circular way but if you play the animation, the constrained object will loose its 'arc shape trajectory' and will move linearly between keys ( I didn't try, just a guess).

 

Hehe, snow is not far from the studio now, half an hour and you’re on the slope ;))

 

>Hope your ok too and that you find some time for some ski sessions in  Haute-Savoie  ( between xsi sessions ;-) ).

 

Don’t tell me you miss it ;))

 

Jm

 

--- jm Khayat  / PINKA Studio ---

--- 04 50 08 41 12 / www.pinka-prod.com ---

 

 

From: owner-xsi(at)Softimage.COM [mailto:owner-xsi(at)Softimage.COM] On Behalf Of Guillaume Laforge
Sent: jeudi 6 décembre 2007 17:37
To: XSI(at)Softimage.COM
Subject: Re: the Cycle thing

 

>Did you notice some weird behavior or drawbacks on the use of this technique in production ?
I never used it in production but it should be ok as it does nothing special on the rig.
But use it only for translations. For rotations it shouldn't give expected results. You can rotate the constraining object on a frame and see the constrained object moving
in a circular way but if you play the animation, the constrained object will loose its 'arc shape trajectory' and will move linearly between keys ( I didn't try, just a guess).

>We did solve the IK-FK blend ala Motion builder – where the IK rig drives the FK and vice versa - with that same technique.
Yes it is the perfect scenario for a selection event ;-).

Hope your ok too and that you find some time for some ski sessions in  Haute-Savoie  ( between xsi sessions ;-) ).

Cheers

Guillaume



JM Khayat - PÏNKA a écrit :

Salut Guillaume

I hope you’re ok.

 

Thanks for your input. It’s in fact comforting us in the direction of how resolving this issue.

We did solve the IK-FK blend ala Motion builder – where the IK rig drives the FK and vice versa - with that same technique.

The tests we made so far on our in-house basic human rig are quite encouraging.

 

Did you notice some weird behavior or drawbacks on the use of this technique in production ?

 

Thanks

 

Jm

 

--- jm Khayat  / PINKA Studio ---

--- 04 50 08 41 12 / www.pinka-prod.com ---

 

 

 

From: owner-xsi(at)Softimage.COM [mailto:owner-xsi(at)Softimage.COM] On Behalf Of guillaume laforge
Sent: mercredi 5 décembre 2007 23:31
To: XSI(at)Softimage.COM
Subject: Re: the Cycle thing

 

Salut Jean Marc,

You can avoid the cycle issue if you don't create the relation at "animation time". Just create the relation at "manipulation time" :-).
The "On Selection Change Event" is your friend for this kind of manipulations.

Here is a quick test : http://www.vol2nuit.fr/guillaume/selection_event/selection_event

There is an inactive pose constraint on each cubes. If you select cube1, cube2 constraint is active and vice-versa.

When you select the arrow, the constraints are inactive and you can play the animation.

I never use a such "manipulation setup" in production, so maybe there is something wrong with this technique...


Cheers

Guillaume

On Dec 5, 2007 12:49 PM, JM Khayat - PÏNKA <jmkhayat(at)pinka-prod.com> wrote:

Hi all

 

Two existential questions from our TD department here :

 

First is : Is it possible to create a relation between 2 objects which are influencing each other, without creating the « cycle » issue ?

 

For example :

Obj A position influences Obj B position and Obj B position influences Obj A position back again.

 

Can we think of creating a bi-directional constraint via a Script Operator ?

 

And another one : Is it possible to create a Script operator to deal with global transformations of an object, while keeping the possibility to move this object with the Move tool in the UI ?

 

Thanks for your help

 

Jm

 

--- jm Khayat  / PINKA Studio ---

--- 04 50 08 41 12 / www.pinka-prod.com ---

 

 

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