Forums > Jitter

importing 3d objects with joints


ico
May 31, 2007 | 9:59 pm

Hi all,

Is there a way to import 3d objects with joints into Jitter and if so, is it
possible to address each joint separately in order to simulate physics?

Many thanks!

Ivica Ico Bukvic, D.M.A.
Composition, Music Technology, CCTAD, CHCI
Virginia Tech
Dept. of Music – 0240
Blacksburg, VA 24061
(540) 231-1137
(540) 231-5034 (fax)
ico@vt.edu
http://www.music.vt.edu/people/faculty/bukvic/

http://ico.bukvic.net


May 31, 2007 | 10:22 pm

What format is the joint data in?

wes

On 5/31/07, Ivica Ico Bukvic wrote:
> Hi all,
>
> Is there a way to import 3d objects with joints into Jitter and if so, is it
> possible to address each joint separately in order to simulate physics?
>
> Many thanks!
>
> Ivica Ico Bukvic, D.M.A.
> Composition, Music Technology, CCTAD, CHCI
> Virginia Tech
> Dept. of Music – 0240
> Blacksburg, VA 24061
> (540) 231-1137
> (540) 231-5034 (fax)
> ico@vt.edu
> http://www.music.vt.edu/people/faculty/bukvic/
> http://ico.bukvic.net
>
>
>
>



ico
June 1, 2007 | 12:35 am

None specific. I am wondering whether this can be used at all in Jitter in
the first place. If this was possible, then my second questions was your
first one ;-).

Ico

> —–Original Message—–
> From: jitter-bounces@cycling74.com [mailto:jitter-bounces@cycling74.com]
> On Behalf Of Wesley Smith
> Sent: Thursday, May 31, 2007 6:23 PM
> Subject: Re: [jitter] importing 3d objects with joints
>
> What format is the joint data in?
>
> wes
>
> On 5/31/07, Ivica Ico Bukvic wrote:
> > Hi all,
> >
> > Is there a way to import 3d objects with joints into Jitter and if so,
> is it
> > possible to address each joint separately in order to simulate physics?
> >
> > Many thanks!
> >
> > Ivica Ico Bukvic, D.M.A.
> > Composition, Music Technology, CCTAD, CHCI
> > Virginia Tech
> > Dept. of Music – 0240
> > Blacksburg, VA 24061
> > (540) 231-1137
> > (540) 231-5034 (fax)
> > ico@vt.edu
> > http://www.music.vt.edu/people/faculty/bukvic/
> > http://ico.bukvic.net
> >
> >
> >
> >


June 1, 2007 | 1:32 am

Here is how you could do it, but it is not trivial. That said it is
also not incredibly difficult. It will just take some time. What you
want to do is export your model and for each vertex export a list of
bones they are attached to along with a corresponding weighting
factor. Usually vertices will have 3 or 4 bones with the total weight
adding to 1. Once you have this, you will export your bone
orientations and positions which can be in a number of formats but
will eventually need to be converted to a 3×4 matrix (modelview matrix
without the last row). This data, sent to a skinning shader will
animate your mesh according to the underlying bone structure and it
will look good.

As far as joints are concerned, you could model them in jit.gl.lua
with the ODE module. Just figure out who to setup the different joint
types in ODE and position them correctly, and the simulation should
take care of the rest.

best,
wes

On 5/31/07, Ivica Ico Bukvic wrote:
> None specific. I am wondering whether this can be used at all in Jitter in
> the first place. If this was possible, then my second questions was your
> first one ;-).
>
> Ico
>
> > —–Original Message—–
> > From: jitter-bounces@cycling74.com [mailto:jitter-bounces@cycling74.com]
> > On Behalf Of Wesley Smith
> > Sent: Thursday, May 31, 2007 6:23 PM
> > Subject: Re: [jitter] importing 3d objects with joints
> >
> > What format is the joint data in?
> >
> > wes
> >
> > On 5/31/07, Ivica Ico Bukvic
wrote:
> > > Hi all,
> > >
> > > Is there a way to import 3d objects with joints into Jitter and if so,
> > is it
> > > possible to address each joint separately in order to simulate physics?
> > >
> > > Many thanks!
> > >
> > > Ivica Ico Bukvic, D.M.A.
> > > Composition, Music Technology, CCTAD, CHCI
> > > Virginia Tech
> > > Dept. of Music – 0240
> > > Blacksburg, VA 24061
> > > (540) 231-1137
> > > (540) 231-5034 (fax)
> > > ico@vt.edu
> > > http://www.music.vt.edu/people/faculty/bukvic/
> > > http://ico.bukvic.net
> > >
> > >
> > >
> > >
>
>



ico
June 1, 2007 | 2:34 am

Many thanks for the explanation. All this being said, is there a particular
3d modeler software that makes this transition less cumbersome than others?

Also, I am just curious if anyone has already had a chance to actually
implement some of this?

Best wishes,

Ico

> —–Original Message—–
> From: jitter-bounces@cycling74.com [mailto:jitter-bounces@cycling74.com]
> On Behalf Of Wesley Smith
> Sent: Thursday, May 31, 2007 9:32 PM
> Subject: Re: [jitter] importing 3d objects with joints
>
> Here is how you could do it, but it is not trivial. That said it is
> also not incredibly difficult. It will just take some time. What you
> want to do is export your model and for each vertex export a list of
> bones they are attached to along with a corresponding weighting
> factor. Usually vertices will have 3 or 4 bones with the total weight
> adding to 1. Once you have this, you will export your bone
> orientations and positions which can be in a number of formats but
> will eventually need to be converted to a 3×4 matrix (modelview matrix
> without the last row). This data, sent to a skinning shader will
> animate your mesh according to the underlying bone structure and it
> will look good.
>
> As far as joints are concerned, you could model them in jit.gl.lua
> with the ODE module. Just figure out who to setup the different joint
> types in ODE and position them correctly, and the simulation should
> take care of the rest.
>
> best,
> wes
>
> On 5/31/07, Ivica Ico Bukvic wrote:
> > None specific. I am wondering whether this can be used at all in Jitter
> in
> > the first place. If this was possible, then my second questions was your
> > first one ;-).
> >
> > Ico
> >
> > > —–Original Message—–
> > > From: jitter-bounces@cycling74.com [mailto:jitter-
> bounces@cycling74.com]
> > > On Behalf Of Wesley Smith
> > > Sent: Thursday, May 31, 2007 6:23 PM
> > > Subject: Re: [jitter] importing 3d objects with joints
> > >
> > > What format is the joint data in?
> > >
> > > wes
> > >
> > > On 5/31/07, Ivica Ico Bukvic
wrote:
> > > > Hi all,
> > > >
> > > > Is there a way to import 3d objects with joints into Jitter and if
> so,
> > > is it
> > > > possible to address each joint separately in order to simulate
> physics?
> > > >
> > > > Many thanks!
> > > >
> > > > Ivica Ico Bukvic, D.M.A.
> > > > Composition, Music Technology, CCTAD, CHCI
> > > > Virginia Tech
> > > > Dept. of Music – 0240
> > > > Blacksburg, VA 24061
> > > > (540) 231-1137
> > > > (540) 231-5034 (fax)
> > > > ico@vt.edu
> > > > http://www.music.vt.edu/people/faculty/bukvic/
> > > > http://ico.bukvic.net
> > > >
> > > >
> > > >
> > > >
> >
> >


June 1, 2007 | 2:45 am

The closest ive come to any of this is object morphing with same
vertex count objects, and ones that are fairly simple too.

I would love to see this work, as a current project could really come
to life with anything learned from this. I also remember seeing
someone’s webpage who frequents the list who did a human model in 3D
that looked like it was animated, but names escape me.

On May 31, 2007, at 10:34 PM, Ivica Ico Bukvic wrote:

> Many thanks for the explanation. All this being said, is there a
> particular
> 3d modeler software that makes this transition less cumbersome than
> others?
>
> Also, I am just curious if anyone has already had a chance to actually
> implement some of this?
>
> Best wishes,
>
> Ico
>
>> —–Original Message—–
>> From: jitter-bounces@cycling74.com [mailto:jitter-
>> bounces@cycling74.com]
>> On Behalf Of Wesley Smith
>> Sent: Thursday, May 31, 2007 9:32 PM
>> Subject: Re: [jitter] importing 3d objects with joints
>>
>> Here is how you could do it, but it is not trivial. That said it is
>> also not incredibly difficult. It will just take some time. What
>> you
>> want to do is export your model and for each vertex export a list of
>> bones they are attached to along with a corresponding weighting
>> factor. Usually vertices will have 3 or 4 bones with the total
>> weight
>> adding to 1. Once you have this, you will export your bone
>> orientations and positions which can be in a number of formats but
>> will eventually need to be converted to a 3×4 matrix (modelview
>> matrix
>> without the last row). This data, sent to a skinning shader will
>> animate your mesh according to the underlying bone structure and it
>> will look good.
>>
>> As far as joints are concerned, you could model them in jit.gl.lua
>> with the ODE module. Just figure out who to setup the different
>> joint
>> types in ODE and position them correctly, and the simulation should
>> take care of the rest.
>>
>> best,
>> wes
>>
>> On 5/31/07, Ivica Ico Bukvic wrote:
>>> None specific. I am wondering whether this can be used at all in
>>> Jitter
>> in
>>> the first place. If this was possible, then my second questions
>>> was your
>>> first one ;-).
>>>
>>> Ico
>>>
>>>> —–Original Message—–
>>>> From: jitter-bounces@cycling74.com [mailto:jitter-
>> bounces@cycling74.com]
>>>> On Behalf Of Wesley Smith
>>>> Sent: Thursday, May 31, 2007 6:23 PM
>>>> Subject: Re: [jitter] importing 3d objects with joints
>>>>
>>>> What format is the joint data in?
>>>>
>>>> wes
>>>>
>>>> On 5/31/07, Ivica Ico Bukvic
wrote:
>>>>> Hi all,
>>>>>
>>>>> Is there a way to import 3d objects with joints into Jitter and if
>> so,
>>>> is it
>>>>> possible to address each joint separately in order to simulate
>> physics?
>>>>>
>>>>> Many thanks!
>>>>>
>>>>> Ivica Ico Bukvic, D.M.A.
>>>>> Composition, Music Technology, CCTAD, CHCI
>>>>> Virginia Tech
>>>>> Dept. of Music – 0240
>>>>> Blacksburg, VA 24061
>>>>> (540) 231-1137
>>>>> (540) 231-5034 (fax)
>>>>> ico@vt.edu
>>>>> http://www.music.vt.edu/people/faculty/bukvic/
>>>>> http://ico.bukvic.net
>>>>>
>>>>>
>>>>>
>>>>>
>>>
>>>
>

v a d e //

http://www.vade.info
abstrakt.vade.info


June 1, 2007 | 2:58 am

I think they used OSC to send to a 3d modelling program. That is
certainly the easiest way to go. For getting the data in Jitter, your
guess is as good as mine. I don’t really use 3d modelling programs.
The one time I tried to get the bone and weight data from Maya, I was
confronted with having to write a C++ plugin. I wasn’t about to go
there because the Maya docs are pretty crap when it comes to their
plugin API. I would love for this to be possible though as Maya has a
fantastic interface for creating skinning weights and joints.

wes

On 5/31/07, vade wrote:
> The closest ive come to any of this is object morphing with same vertex
> count objects, and ones that are fairly simple too.
>
> I would love to see this work, as a current project could really come to
> life with anything learned from this. I also remember seeing someone’s
> webpage who frequents the list who did a human model in 3D that looked like
> it was animated, but names escape me.
>
>
>
>
>
> On May 31, 2007, at 10:34 PM, Ivica Ico Bukvic wrote:
>
> Many thanks for the explanation. All this being said, is there a particular
> 3d modeler software that makes this transition less cumbersome than others?
>
> Also, I am just curious if anyone has already had a chance to actually
> implement some of this?
>
> Best wishes,
>
> Ico
>
>
> —–Original Message—–
> From: jitter-bounces@cycling74.com
> [mailto:jitter-bounces@cycling74.com]
> On Behalf Of Wesley Smith
> Sent: Thursday, May 31, 2007 9:32 PM
> Subject: Re: [jitter] importing 3d objects with joints
>
> Here is how you could do it, but it is not trivial. That said it is
> also not incredibly difficult. It will just take some time. What you
> want to do is export your model and for each vertex export a list of
> bones they are attached to along with a corresponding weighting
> factor. Usually vertices will have 3 or 4 bones with the total weight
> adding to 1. Once you have this, you will export your bone
> orientations and positions which can be in a number of formats but
> will eventually need to be converted to a 3×4 matrix (modelview matrix
> without the last row). This data, sent to a skinning shader will
> animate your mesh according to the underlying bone structure and it
> will look good.
>
> As far as joints are concerned, you could model them in jit.gl.lua
> with the ODE module. Just figure out who to setup the different joint
> types in ODE and position them correctly, and the simulation should
> take care of the rest.
>
> best,
> wes
>
> On 5/31/07, Ivica Ico Bukvic wrote:
> None specific. I am wondering whether this can be used at all in Jitter
> in
> the first place. If this was possible, then my second questions was your
> first one ;-).
>
> Ico
>
>
> —–Original Message—–
> From: jitter-bounces@cycling74.com [mailto:jitter-
> bounces@cycling74.com]
>
> On Behalf Of Wesley Smith
> Sent: Thursday, May 31, 2007 6:23 PM
> Subject: Re: [jitter] importing 3d objects with joints
>
> What format is the joint data in?
>
> wes
>
> On 5/31/07, Ivica Ico Bukvic
wrote:
> Hi all,
>
> Is there a way to import 3d objects with joints into Jitter and if
> so,
>
> is it
> possible to address each joint separately in order to simulate
> physics?
>
>
> Many thanks!
>
> Ivica Ico Bukvic, D.M.A.
> Composition, Music Technology, CCTAD, CHCI
> Virginia Tech
> Dept. of Music – 0240
> Blacksburg, VA 24061
> (540) 231-1137
> (540) 231-5034 (fax)
> ico@vt.edu
> http://www.music.vt.edu/people/faculty/bukvic/
> http://ico.bukvic.net
>
>
>
>
>
>
>
>
>
>
> v a d e //
>
> http://www.vade.info
> abstrakt.vade.info
>
>
>
>
>
>


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