path constraint via ICE

[Ponthieux, Joseph G. (LARC-E1A)[LITES]]

Is there a way to perform a path constraint using ICE?

I'm certain that it can be done but I can't find a task or tool prepackaged to 
do this.


Thanks

--
Joey Ponthieux
LaRC Information Technology Enhanced Services (LITES)
Mymic Technical Services
NASA Langley Research Center
__
Opinions stated here-in are strictly those of the author and do not
represent the opinions of NASA or any other party.

Re: path constraint via ICE

[Alan Fregtman]

http://s3.darkvertex.com/hlinked/ice/ICE_example_kinematics_pathOrCurveUConstraint.png

Maybe something like this? You may need to do more to deal with the
upvector better if your curve complexity is intense.



On Wed, Jun 26, 2013 at 10:34 AM, Ponthieux, Joseph G. (LARC-E1A)[LITES] <
j.ponthi...@nasa.gov> wrote:

> Is there a way to perform a path constraint using ICE?
>
> ** **
>
> I’m certain that it can be done but I can’t find a task or tool
> prepackaged to do this.
>
> ** **
>
> ** **
>
> Thanks
>
> ** **
>
> --
>
> Joey Ponthieux
>
> LaRC Information Technology Enhanced Services (LITES)
>
> Mymic Technical Services
>
> NASA Langley Research Center
>
> __
>
> Opinions stated here-in are strictly those of the author and do not 
>
> represent the opinions of NASA or any other party.
>
> ** **
>

Re: path constraint via ICE

[Morten Bartholdy]

Pretty cool Alan! So tangency is controlled in the Increment Rotation node
- how would I control the upvector, say with another null?
To better understand how it works, how come it is necessary to key the null
to zero rot and pos for it to work?

Morten




Den 26. juni 2013 kl. 16:45 skrev Alan Fregtman :

> http://s3.darkvertex.com/hlinked/ice/ICE_example_kinematics_pathOrCurveUConstraint.png
> 
> 
> Maybe something like this? You may need to do more to deal with the
> upvector better if your curve complexity is intense.
> 
> 
> 
> On Wed, Jun 26, 2013 at 10:34 AM, Ponthieux, Joseph G. (LARC-E1A)[LITES] <
> j.ponthi...@nasa.gov  > wrote:
> > 
> > Is there a way to perform a path constraint using ICE?
> > 
> > 
> > 
> > I’m certain that it can be done but I can’t find a task or tool prepackaged
> > to do this.
> > 
> > 
> > 
> > 
> > 
> > Thanks
> > 
> > 
> > 
> > --
> > 
> > Joey Ponthieux
> > 
> > LaRC Information Technology Enhanced Services (LITES)
> > 
> > Mymic Technical Services
> > 
> > NASA Langley Research Center
> > 
> > __
> > 
> > Opinions stated here-in are strictly those of the author and do not
> > 
> > represent the opinions of NASA or any other party.
> > 
> > 
> > 

Re: path constraint via ICE

[Daniel Harjanto]

It's been a while I didn't visit my own site, but some years ago I made a
writing explaining Phil Taylor video on path constraint with ICE.

Maybe it can help,

Cheers,


On Wed, Jun 26, 2013 at 9:34 PM, Ponthieux, Joseph G. (LARC-E1A)[LITES] <
j.ponthi...@nasa.gov> wrote:

> Is there a way to perform a path constraint using ICE?
>
> ** **
>
> I’m certain that it can be done but I can’t find a task or tool
> prepackaged to do this.
>
> ** **
>
> ** **
>
> Thanks
>
> ** **
>
> --
>
> Joey Ponthieux
>
> LaRC Information Technology Enhanced Services (LITES)
>
> Mymic Technical Services
>
> NASA Langley Research Center
>
> __
>
> Opinions stated here-in are strictly those of the author and do not 
>
> represent the opinions of NASA or any other party.
>
> ** **
>



-- 
Daniel Harjanto
Infinite Frameworks Studios
TD
http://misterdi.cgpot.com

Re: path constraint via ICE

[Daniel Harjanto]

http://misterdi.cgpot.com/tutorial/PathConstraint_with_ICE/PathConstraint_with_ICE.html



On Fri, Jun 28, 2013 at 4:55 PM, Daniel Harjanto wrote:

> It's been a while I didn't visit my own site, but some years ago I made a
> writing explaining Phil Taylor video on path constraint with ICE.
>
> Maybe it can help,
>
> Cheers,
>
>
> On Wed, Jun 26, 2013 at 9:34 PM, Ponthieux, Joseph G. (LARC-E1A)[LITES] <
> j.ponthi...@nasa.gov> wrote:
>
>> Is there a way to perform a path constraint using ICE?
>>
>> ** **
>>
>> I’m certain that it can be done but I can’t find a task or tool
>> prepackaged to do this.
>>
>> ** **
>>
>> ** **
>>
>> Thanks
>>
>> ** **
>>
>> --
>>
>> Joey Ponthieux
>>
>> LaRC Information Technology Enhanced Services (LITES)
>>
>> Mymic Technical Services
>>
>> NASA Langley Research Center
>>
>> __
>>
>> Opinions stated here-in are strictly those of the author and do not 
>>
>> represent the opinions of NASA or any other party.
>>
>> ** **
>>
>
>
>
> --
> Daniel Harjanto
> Infinite Frameworks Studios
> TD
> http://misterdi.cgpot.com
>



-- 
Daniel Harjanto
Infinite Frameworks Studios
TD
http://misterdi.cgpot.com

Re: path constraint via ICE

[olivier jeannel]

  
  
I don't know the official way, but
  since the tangency will control the rotation on one axis, you just
  need to add a second Set Rotation that look UP on another axis.
  Like this :
  
  (Local vector set to 0, 1, 0 )
  
  Le 28/06/2013 10:49, Morten Bartholdy a écrit :


  
   Pretty cool Alan! So tangency is
  controlled in the Increment Rotation node - how would I
  control the upvector, say with another null? 
   To better understand how it works,
  how come it is necessary to key the null to zero rot and pos
  for it to work? 
     
   Morten 
     
     
   
Den 26. juni 2013 kl. 16:45 skrev Alan Fregtman
: 


  

   http://s3.darkvertex.com/hlinked/ice/ICE_example_kinematics_pathOrCurveUConstraint.png
  
   
  Maybe something like this? You may need to do more to deal
  with the upvector better if your curve complexity is
  intense.
   

 
  
   On Wed, Jun 26, 2013 at 10:34
AM, Ponthieux, Joseph G. (LARC-E1A)[LITES]  <
  j.ponthi...@nasa.gov
  >  wrote: 

  

  Is there a way to perform a
path constraint using ICE?
   
  I’m certain that it can be
done but I can’t find a task or tool prepackaged
to do this.
   
   
  Thanks
   
  --
  Joey Ponthieux
  LaRC Information Technology
Enhanced Services (LITES)
  Mymic Technical Services
  NASA Langley Research Center
  __
  Opinions stated here-in are
strictly those of the author and do not
  represent the opinions of
NASA or any other party.
   

  

  

  
  
    
  


  

Re: path constraint via ICE

[Edy Susanto Lim]

Hi,
If we use object as an upvector, then we don't need the Increment Rotation
with 2 vectors compound. We can just use 'Direction to Rotation' node.
-tangent as 'Point At'
-the position difference of the upvector object position to the curve
position as 'Up Vector'

Cheers,
edy


On Fri, Jun 28, 2013 at 5:58 PM, olivier jeannel wrote:

>  I don't know the official way, but since the tangency will control the
> rotation on one axis, you just need to add a second Set Rotation that look
> UP on another axis.
> Like this :
>
> (Local vector set to 0, 1, 0 )
>
> Le 28/06/2013 10:49, Morten Bartholdy a écrit :
>
>  Pretty cool Alan! So tangency is controlled in the Increment Rotation
> node - how would I control the upvector, say with another null?
>
> To better understand how it works, how come it is necessary to key the
> null to zero rot and pos for it to work?
>
>
>
> Morten
>
>
>
>
>
> Den 26. juni 2013 kl. 16:45 skrev Alan Fregtman 
> :
>
>
>
> http://s3.darkvertex.com/hlinked/ice/ICE_example_kinematics_pathOrCurveUConstraint.png
>
> Maybe something like this? You may need to do more to deal with the
> upvector better if your curve complexity is intense.
>
>
>
>  On Wed, Jun 26, 2013 at 10:34 AM, Ponthieux, Joseph G. (LARC-E1A)[LITES] <
> j.ponthi...@nasa.gov > wrote:
>
>  Is there a way to perform a path constraint using ICE?
>
>
>
> I’m certain that it can be done but I can’t find a task or tool
> prepackaged to do this.
>
>
>
>
>
> Thanks
>
>
>
> --
>
> Joey Ponthieux
>
> LaRC Information Technology Enhanced Services (LITES)
>
> Mymic Technical Services
>
> NASA Langley Research Center
>
> __
>
> Opinions stated here-in are strictly those of the author and do not
>
> represent the opinions of NASA or any other party.
>
>
>
>
>
>
>
>


-- 
Edy Susanto Lim
TD
http://sawamura.neorack.com
<>

Re: path constraint via ICE

[olivier jeannel]

  
  
Even better :)
  
  Le 28/06/2013 12:22, Edy Susanto Lim a écrit :


  Hi,
If we use object as an upvector, then we don't
  need the Increment Rotation with 2 vectors compound. We can
  just use 'Direction to Rotation' node. 
-tangent as 'Point At' 
-the position difference of the upvector object
  position to the curve position as 'Up Vector'


Cheers,
edy
  
  

On Fri, Jun 28, 2013 at 5:58 PM,
  olivier jeannel 
  wrote:
  

  I don't know the official way, but since the tangency
will control the rotation on one axis, you just need to
add a second Set Rotation that look UP on another axis.
Like this :

(Local vector set to 0, 1, 0 )

Le 28/06/2013 10:49, Morten Bartholdy a écrit :
  
  

  
 Pretty cool Alan! So
tangency is controlled in the Increment Rotation
node - how would I control the upvector, say
with another null? 
 To better understand how
it works, how come it is necessary to key the
null to zero rot and pos for it to work?

   
 Morten 
   
   
 
  Den 26. juni 2013 kl. 16:45 skrev Alan Fregtman :
  
  
  

  
 http://s3.darkvertex.com/hlinked/ice/ICE_example_kinematics_pathOrCurveUConstraint.png

 
Maybe something like this? You may need to
do more to deal with the upvector better if
your curve complexity is intense.
 
  
   

 On Wed, Jun 26,
  2013 at 10:34 AM, Ponthieux, Joseph G.
  (LARC-E1A)[LITES]  < j.ponthi...@nasa.gov
>  wrote: 
  

  
Is there a way
  to perform a path constraint using
  ICE?
 
I’m certain
  that it can be done but I can’t
  find a task or tool prepackaged to
  do this.
 
 
Thanks
 
--
Joey Ponthieux
LaRC
  Information Technology Enhanced
  Services (LITES)
Mymic Technical
  Services
NASA Langley
  Research Center
__
Opinions stated
  here-in are strictly those of the
  author and do not
represent the
  opinions of NASA or any other
  party.
 
  

  

  


  

  
  

  

  





-- 
Edy Susanto Lim
TD
http://sawamura.neorack.com
  


  

Re: path constraint via ICE

[paul]

If you want to have a % driven ‘path’ constrain as these examples are a ‘param’ 
type constraint, Its more complex.
If you have a null constrained in the middle, and you pull one end of a curve, 
it wont react on a param. (unless it only has 2 points) but with a % version, 
it will always stay at 50% of the length so slide along the curve.
I managed to get one working using Nest’s Strandfitting compound and the fit 
bezier node, but it would be nice for this to be exposed without the faff.
Paul

From: olivier jeannel 
Sent: Friday, June 28, 2013 12:57 PM
To: softimage@listproc.autodesk.com 
Subject: Re: path constraint via ICE

Even better :)

Le 28/06/2013 12:22, Edy Susanto Lim a écrit :

  Hi, 
  If we use object as an upvector, then we don't need the Increment Rotation 
with 2 vectors compound. We can just use 'Direction to Rotation' node. 
  -tangent as 'Point At' 
  -the position difference of the upvector object position to the curve 
position as 'Up Vector'

  Cheers,
  edy



  On Fri, Jun 28, 2013 at 5:58 PM, olivier jeannel  
wrote:

I don't know the official way, but since the tangency will control the 
rotation on one axis, you just need to add a second Set Rotation that look UP 
on another axis.
Like this :

(Local vector set to 0, 1, 0 )

Le 28/06/2013 10:49, Morten Bartholdy a écrit :

  Pretty cool Alan! So tangency is controlled in the Increment Rotation 
node - how would I control the upvector, say with another null? 

  To better understand how it works, how come it is necessary to key the 
null to zero rot and pos for it to work? 


  Morten 




  Den 26. juni 2013 kl. 16:45 skrev Alan Fregtman 
mailto:alan.fregt...@gmail.com: 



http://s3.darkvertex.com/hlinked/ice/ICE_example_kinematics_pathOrCurveUConstraint.png
 

Maybe something like this? You may need to do more to deal with the 
upvector better if your curve complexity is intense. 




On Wed, Jun 26, 2013 at 10:34 AM, Ponthieux, Joseph G. 
(LARC-E1A)[LITES] < j.ponthi...@nasa.gov > wrote: 

  Is there a way to perform a path constraint using ICE?



  I’m certain that it can be done but I can’t find a task or tool 
prepackaged to do this.





  Thanks



  --

  Joey Ponthieux

  LaRC Information Technology Enhanced Services (LITES)

  Mymic Technical Services

  NASA Langley Research Center

  __

  Opinions stated here-in are strictly those of the author and do not

  represent the opinions of NASA or any other party.











  -- 
  Edy Susanto Lim
  TD
  http://sawamura.neorack.com 

<>

Re: path constraint via ICE

[Johan Forsgren]

Thanks guys, I finally got some time to look into it yesterday, and it
worked like a charm, someday when i get some time of i think im going to
redo this effect but this time around make it unsimulated. It feel like I
don't really get the inner working of strands yet, and this would be a
great way to remedy this.  For now this works great :)

On Saturday, June 29, 2013, wrote:

>   If you want to have a % driven ‘path’ constrain as these examples are a
> ‘param’ type constraint, Its more complex.
> If you have a null constrained in the middle, and you pull one end of a
> curve, it wont react on a param. (unless it only has 2 points) but with a %
> version, it will always stay at 50% of the length so slide along the curve.
> I managed to get one working using Nest’s Strandfitting compound and the
> fit bezier node, but it would be nice for this to be exposed without the
> faff.
> Paul
>
>   *From:* olivier jeannel  'olivier.jean...@noos.fr');>
> *Sent:* Friday, June 28, 2013 12:57 PM
> *To:* softimage@listproc.autodesk.com  'softimage@listproc.autodesk.com');>
> *Subject:* Re: path constraint via ICE
>
>  Even better :)
>
> Le 28/06/2013 12:22, Edy Susanto Lim a écrit :
>
> Hi,
> If we use object as an upvector, then we don't need the Increment Rotation
> with 2 vectors compound. We can just use 'Direction to Rotation' node.
> -tangent as 'Point At'
> -the position difference of the upvector object position to the curve
> position as 'Up Vector'
>
> Cheers,
> edy
>
>
> On Fri, Jun 28, 2013 at 5:58 PM, olivier jeannel 
>  'olivier.jean...@noos.fr');>
> > wrote:
>
>>  I don't know the official way, but since the tangency will control the
>> rotation on one axis, you just need to add a second Set Rotation that look
>> UP on another axis.
>> Like this :
>>
>> (Local vector set to 0, 1, 0 )
>>
>> Le 28/06/2013 10:49, Morten Bartholdy a écrit :
>>
>> Pretty cool Alan! So tangency is controlled in the Increment Rotation
>> node - how would I control the upvector, say with another null?
>>
>> To better understand how it works, how come it is necessary to key the
>> null to zero rot and pos for it to work?
>>
>> Morten
>>
>>
>> Den 26. juni 2013 kl. 16:45 skrev Alan Fregtman
>> mailto:alan.fregt...@gmail.com > 'alan.fregt...@gmail.com');>:
>>
>>
>> http://s3.darkvertex.com/hlinked/ice/ICE_example_kinematics_pathOrCurveUConstraint.png
>>
>> Maybe something like this? You may need to do more to deal with the
>> upvector better if your curve complexity is intense.
>>
>>
>>
>> On Wed, Jun 26, 2013 at 10:34 AM, Ponthieux, Joseph G. (LARC-E1A)[LITES] <
>> j.ponthi...@nasa.gov > 
>> wrote:
>>
>>
>>  Is there a way to perform a path constraint using ICE?
>>
>>
>>
>> I’m certain that it can be done but I can’t find a task or tool
>> prepackaged to do this.
>>
>>
>>
>>
>>
>> Thanks
>>
>>
>>
>> --
>>
>> Joey Ponthieux
>>
>> LaRC Information Technology Enhanced Services (LITES)
>>
>> Mymic Technical Services
>>
>> NASA Langley Research Center
>>
>> __
>>
>> Opinions stated here-in are strictly those of the author and do not
>>
>> represent the opinions of NASA or any other party.
>>
>>
>>
>>
>>
>>
>>
>>
>
>
> --
> Edy Susanto Lim
> TD
> http://sawamura.neorack.com
>
>
>

-- 
Sent from my fax machine.

RE: path constraint via ICE

[Ponthieux, Joseph G. (LARC-E1A)[LITES]]

An update. I have managed to piece together a "constrain on path" node which 
operates directly from the local or parent object(as opposed to being applied 
from a cloud or secondary object). I currently have path constrain position and 
tangency working on a normalized path. I also have it supporting a crude 
velocity along path in units per second.

What I don't have working at this time is up vector and scaling. Apparently if 
I scale the object this affects position and is not desirable. My guess is that 
this is due to the same inversion/ transposition requirements to the matrix 
which is necessary to make the constraint position and tangency work when the 
node is applied locally to the constrained object. I just need to get the 
scaling inversion worked out I think.

I managed to get the normalization(what Paul was referring too) working through 
the Normalized U to Curve Location node but it requires a high accuracy 
level(steps) to precisely match SI's core path constraint  1:1. When structured 
as strictly normalized  its very reliable, but is also slow to process at a 
high step count.  I tried to have it  switchable between param and normalized 
modes but ran into stability issues here. What is really needed at this point 
is for the core UV To Location node to be compiled to support both param and 
normalized interpolation in real time. Not really sure why this is not standard?

If anyone has any suggestions on how to address the scaling problem, it would 
be appreciated.

--
Joey Ponthieux
LaRC Information Technology Enhanced Services (LITES)
Mymic Technical Services
NASA Langley Research Center
__
Opinions stated here-in are strictly those of the author and do not
represent the opinions of NASA or any other party.

From: softimage-boun...@listproc.autodesk.com 
[mailto:softimage-boun...@listproc.autodesk.com] On Behalf Of Johan Forsgren
Sent: Thursday, July 04, 2013 12:55 PM
To: softimage@listproc.autodesk.com
Subject: Re: path constraint via ICE

Thanks guys, I finally got some time to look into it yesterday, and it worked 
like a charm, someday when i get some time of i think im going to redo this 
effect but this time around make it unsimulated. It feel like I don't really 
get the inner working of strands yet, and this would be a great way to remedy 
this.  For now this works great :)

On Saturday, June 29, 2013, wrote:
If you want to have a % driven 'path' constrain as these examples are a 'param' 
type constraint, Its more complex.
If you have a null constrained in the middle, and you pull one end of a curve, 
it wont react on a param. (unless it only has 2 points) but with a % version, 
it will always stay at 50% of the length so slide along the curve.
I managed to get one working using Nest's Strandfitting compound and the fit 
bezier node, but it would be nice for this to be exposed without the faff.
Paul

From: olivier 
jeannel
Sent: Friday, June 28, 2013 12:57 PM
To: 
softimage@listproc.autodesk.com
Subject: Re: path constraint via ICE

Even better :)

Le 28/06/2013 12:22, Edy Susanto Lim a écrit :
Hi,
If we use object as an upvector, then we don't need the Increment Rotation with 
2 vectors compound. We can just use 'Direction to Rotation' node.
-tangent as 'Point At'
-the position difference of the upvector object position to the curve position 
as 'Up Vector'

Cheers,
edy

On Fri, Jun 28, 2013 at 5:58 PM, olivier jeannel 
>
 wrote:
I don't know the official way, but since the tangency will control the rotation 
on one axis, you just need to add a second Set Rotation that look UP on another 
axis.
Like this :

(Local vector set to 0, 1, 0 )

Le 28/06/2013 10:49, Morten Bartholdy a écrit :

Pretty cool Alan! So tangency is controlled in the Increment Rotation node - 
how would I control the upvector, say with another null?

To better understand how it works, how come it is necessary to key the null to 
zero rot and pos for it to work?

Morten

Den 26. juni 2013 kl. 16:45 skrev Alan Fregtman 
mailto:alan.fregt...@gmail.com:
http://s3.darkvertex.com/hlinked/ice/ICE_example_kinematics_pathOrCurveUConstraint.png

Maybe something like this? You may need to do more to deal with the upvector 
better if your curve complexity is intense.


On Wed, Jun 26, 2013 at 10:34 AM, Ponthieux, Joseph G. (LARC-E1A)[LITES] < 
j.ponthi...@nasa.gov
 > wrote:
Is there a way to perform a path constraint using ICE?

I'm certain that it can be done but I can't find a task or tool prepackaged to 
do this.


Thanks

--
Joey Ponthieux
LaRC Information Technology Enhanced Services (LITES)
Mymic Technical Services
NASA Langley Research Center
__
Opinions stated here-in are strictly those of the author and do not
represent the opinions of NASA or any other party.







--
Edy Susanto Lim
TD
http://sawamura.neorack.com



--
Sent from my fax machine.

Re: path constraint via ICE

[Stephen Davidson]

Why not have a null follow the path, and have the object position
constrained to the null?
That way you can also control the center of the scale, and the object
scaling will
not effect the position, since it is based on the null position.


On Mon, Jul 8, 2013 at 10:49 AM, Ponthieux, Joseph G. (LARC-E1A)[LITES] <
j.ponthi...@nasa.gov> wrote:

> An update. I have managed to piece together a “constrain on path” node
> which operates directly from the local or parent object(as opposed to being
> applied from a cloud or secondary object). I currently have path constrain
> position and tangency working on a normalized path. I also have it
> supporting a crude velocity along path in units per second.
>
> ** **
>
> What I don’t have working at this time is up vector and scaling.
> Apparently if I scale the object this affects position and is not
> desirable. My guess is that this is due to the same inversion/
> transposition requirements to the matrix which is necessary to make the
> constraint position and tangency work when the node is applied locally to
> the constrained object. I just need to get the scaling inversion worked out
> I think.
>
> ** **
>
> I managed to get the normalization(what Paul was referring too) working
> through the Normalized U to Curve Location node but it requires a high
> accuracy level(steps) to precisely match SI’s core path constraint  1:1.
> When structured as strictly normalized  its very reliable, but is also slow
> to process at a high step count.  I tried to have it  switchable between
> param and normalized modes but ran into stability issues here. What is
> really needed at this point is for the core UV To Location node to be
> compiled to support both param and normalized interpolation in real time.
> Not really sure why this is not standard?
>
> ** **
>
> If anyone has any suggestions on how to address the scaling problem, it
> would be appreciated.
>
> ** **
>
> --
>
> Joey Ponthieux
>
> LaRC Information Technology Enhanced Services (LITES)
>
> Mymic Technical Services
>
> NASA Langley Research Center
>
> __
>
> Opinions stated here-in are strictly those of the author and do not 
>
> represent the opinions of NASA or any other party.
>
> ** **
>
> *From:* softimage-boun...@listproc.autodesk.com [mailto:
> softimage-boun...@listproc.autodesk.com] *On Behalf Of *Johan Forsgren
> *Sent:* Thursday, July 04, 2013 12:55 PM
>
> *To:* softimage@listproc.autodesk.com
> *Subject:* Re: path constraint via ICE
>
> ** **
>
> Thanks guys, I finally got some time to look into it yesterday, and it
> worked like a charm, someday when i get some time of i think im going to
> redo this effect but this time around make it unsimulated. It feel like I
> don't really get the inner working of strands yet, and this would be a
> great way to remedy this.  For now this works great :)
>
> On Saturday, June 29, 2013, wrote:
>
> If you want to have a % driven ‘path’ constrain as these examples are a
> ‘param’ type constraint, Its more complex.
>
> If you have a null constrained in the middle, and you pull one end of a
> curve, it wont react on a param. (unless it only has 2 points) but with a %
> version, it will always stay at 50% of the length so slide along the curve.
> 
>
> I managed to get one working using Nest’s Strandfitting compound and the
> fit bezier node, but it would be nice for this to be exposed without the
> faff.
>
> Paul
>
>  
>
> *From:* olivier jeannel 
>
> *Sent:* Friday, June 28, 2013 12:57 PM
>
> *To:* softimage@listproc.autodesk.com 
>
> *Subject:* Re: path constraint via ICE
>
>  
>
> Even better :)
>
> Le 28/06/2013 12:22, Edy Susanto Lim a écrit :
>
> Hi, 
>
> If we use object as an upvector, then we don't need the Increment Rotation
> with 2 vectors compound. We can just use 'Direction to Rotation' node. ***
> *
>
> -tangent as 'Point At' 
>
> -the position difference of the upvector object position to the curve
> position as 'Up Vector'
>
>  
>
> Cheers,
>
> edy
>
> ** **
>
> On Fri, Jun 28, 2013 at 5:58 PM, olivier jeannel 
> wrote:
>
> I don't know the official way, but since the tangency will control the
> rotation on one axis, you just need to add a second Set Rotation that look
> UP on another axis.
> Like this :
>
> (Local vector set to 0, 1, 0 )
>
> Le 28/06/2013 10:49, Morten Bartholdy a écrit :
>
> Pretty cool Alan! So tangency is controlled i

RE: path constraint via ICE

[Ponthieux, Joseph G. (LARC-E1A)[LITES]]

I could I suppose, but what I really want from this is something that is 
portable. That's why I put so much effort into making this a node which could 
be local to the object constrained to the path. I'll give it some thought.

Thanks

--
Joey Ponthieux
LaRC Information Technology Enhanced Services (LITES)
Mymic Technical Services
NASA Langley Research Center
__
Opinions stated here-in are strictly those of the author and do not
represent the opinions of NASA or any other party.

From: softimage-boun...@listproc.autodesk.com 
[mailto:softimage-boun...@listproc.autodesk.com] On Behalf Of Stephen Davidson
Sent: Monday, July 08, 2013 3:27 PM
To: softimage@listproc.autodesk.com
Subject: Re: path constraint via ICE

Why not have a null follow the path, and have the object position constrained 
to the null?
That way you can also control the center of the scale, and the object scaling 
will
not effect the position, since it is based on the null position.

On Mon, Jul 8, 2013 at 10:49 AM, Ponthieux, Joseph G. (LARC-E1A)[LITES] 
mailto:j.ponthi...@nasa.gov>> wrote:
An update. I have managed to piece together a "constrain on path" node which 
operates directly from the local or parent object(as opposed to being applied 
from a cloud or secondary object). I currently have path constrain position and 
tangency working on a normalized path. I also have it supporting a crude 
velocity along path in units per second.

What I don't have working at this time is up vector and scaling. Apparently if 
I scale the object this affects position and is not desirable. My guess is that 
this is due to the same inversion/ transposition requirements to the matrix 
which is necessary to make the constraint position and tangency work when the 
node is applied locally to the constrained object. I just need to get the 
scaling inversion worked out I think.

I managed to get the normalization(what Paul was referring too) working through 
the Normalized U to Curve Location node but it requires a high accuracy 
level(steps) to precisely match SI's core path constraint  1:1. When structured 
as strictly normalized  its very reliable, but is also slow to process at a 
high step count.  I tried to have it  switchable between param and normalized 
modes but ran into stability issues here. What is really needed at this point 
is for the core UV To Location node to be compiled to support both param and 
normalized interpolation in real time. Not really sure why this is not standard?

If anyone has any suggestions on how to address the scaling problem, it would 
be appreciated.

--
Joey Ponthieux
LaRC Information Technology Enhanced Services (LITES)
Mymic Technical Services
NASA Langley Research Center
__
Opinions stated here-in are strictly those of the author and do not
represent the opinions of NASA or any other party.

From: 
softimage-boun...@listproc.autodesk.com<mailto:softimage-boun...@listproc.autodesk.com>
 
[mailto:softimage-boun...@listproc.autodesk.com<mailto:softimage-boun...@listproc.autodesk.com>]
 On Behalf Of Johan Forsgren
Sent: Thursday, July 04, 2013 12:55 PM

To: softimage@listproc.autodesk.com<mailto:softimage@listproc.autodesk.com>
Subject: Re: path constraint via ICE

Thanks guys, I finally got some time to look into it yesterday, and it worked 
like a charm, someday when i get some time of i think im going to redo this 
effect but this time around make it unsimulated. It feel like I don't really 
get the inner working of strands yet, and this would be a great way to remedy 
this.  For now this works great :)

On Saturday, June 29, 2013, wrote:
If you want to have a % driven 'path' constrain as these examples are a 'param' 
type constraint, Its more complex.
If you have a null constrained in the middle, and you pull one end of a curve, 
it wont react on a param. (unless it only has 2 points) but with a % version, 
it will always stay at 50% of the length so slide along the curve.
I managed to get one working using Nest's Strandfitting compound and the fit 
bezier node, but it would be nice for this to be exposed without the faff.
Paul

From: olivier jeannel
Sent: Friday, June 28, 2013 12:57 PM
To: softimage@listproc.autodesk.com<mailto:softimage@listproc.autodesk.com>
Subject: Re: path constraint via ICE

Even better :)

Le 28/06/2013 12:22, Edy Susanto Lim a écrit :
Hi,
If we use object as an upvector, then we don't need the Increment Rotation with 
2 vectors compound. We can just use 'Direction to Rotation' node.
-tangent as 'Point At'
-the position difference of the upvector object position to the curve position 
as 'Up Vector'

Cheers,
edy

On Fri, Jun 28, 2013 at 5:58 PM, olivier jeannel 
mailto:olivier.jean...@noos.fr>> wrote:
I don't know the official way, but since the tangency will co