openvrml-develop — OpenVRML developers mailing list

RE: [openvrml-develop] getting coordinates from ViewPoint- and Sound-Nodes

[Michael S. <Mic...@gm...>]

>It worked - but using the inverse matrix:
>After the modelview transform I used the following code:
>
>***snip***
>VrmlMatrix myMV = MV.affine_inverse();
>SFVec3f globalVP(myMV[3][0], myMV[3][1], myMV[3][2]);
>SFVec3f globalVUP(myMV[1][0], myMV[1][1], myMV[1][2]);
>+++snap+++

affine_inverse, aha is logical because the transformation which is applied 
on the modell must be inverse to get the position of the camera,

>...which stores the ViewPoint position w.r.t. the VRML-world coordinate 
>system in globalVP and the view-up vector in globalVUP (as I need it *g*).
>
>> > (2) How can I get the coordinates of a Sound node in the VRML-world
>> > coordinate system?

You can get the MV and multiply it with (0,0,0)  then you have the vector 
from the camera to Object, to get the Position, you may add the current 
position
from Viewpoint in the VRML-world coordinate system, and now add the 
location(field location) of Sound node. I don't know if this work, try it out.

Micha.

RE: [openvrml-develop] getting coordinates from ViewPoint- and Sound-Nodes

[-oli- <ol...@fr...>]

At 12:13 11.04.2002 +0530, S.K. Bose wrote:
> > (1) How can I get the coordinates of the actual ViewPoint, i.e. including
> > the user navigation transformations, in the VRML-world coordinate system
> > (_not_ the OpenGL coordinate system)?
>
>You go through the code "NodeBillboard::billboard_to_matrix(...)" or
>"NodeLOD::render(..)". Here you will find how to get viewer position w.r.t.
>local coordinate system. For your case don't inverse it.

It worked - but using the inverse matrix:
After the modelview transform I used the following code:

***snip***
VrmlMatrix myMV = MV.affine_inverse();
SFVec3f globalVP(myMV[3][0], myMV[3][1], myMV[3][2]);
SFVec3f globalVUP(myMV[1][0], myMV[1][1], myMV[1][2]);
+++snap+++

...which stores the ViewPoint position w.r.t. the VRML-world coordinate 
system in globalVP and the view-up vector in globalVUP (as I need it *g*).


What I still didn't figure out is my second issue:

> > (2) How can I get the coordinates of a Sound node in the VRML-world
> > coordinate system?

I.e. independed of the current ViewPoint and w.r.t. the VRML-world 
coordinate system.
E.g. if the Sound node (field location = (0 2 0)) is a children of a 
Transform node (field translation = (1 0 0)), I need to get the actual 
coordinate of the Sound node, which is (1 2 0).
How can I achieve this??

Thanks again for help!

         -oli-
         (Oliver Baum)

[openvrml-develop] hit_point and touchsensor

[Michael S. <Mic...@gm...>]

Hi,

could it be that the hit_point changed event doesn't worked on the 
touchsensor ??

thx Micha

[openvrml-develop] Sensitive Objects

[Michael S. <Mic...@gm...>]

Hi,

for my Diplomathesis, I can't use the OpenGL Selection Mode for picking 
Objects, i need to implement to draw sensitives object
in a specified color and check if a object is hit by reading the color 
value of the current mouseposition.
Has anyone an idea how to implement this in openvrml. In normal OpenGL it 
works fine.
Any hints are welcome

Thx Michael Schuldt.

RE: [openvrml-develop] getting coordinates from ViewPoint- and Sound-Nodes

[S. K. B. <bo...@pa...>]

> -----Original Message-----
> From: S. K. Bose [mailto:bo...@pa...]
> Sent: Thursday, April 11, 2002 12:14 PM
> To: -oli-; ope...@li...
> Subject: RE: [openvrml-develop] getting coordinates from ViewPoint- and
> Sound-Nodes
> 
> 
> 
> 
> > -----Original Message-----
> > From: ope...@li...
> > [mailto:ope...@li...]On Behalf Of -oli-
> > Sent: Wednesday, April 10, 2002 8:46 PM
> > To: ope...@li...
> > Subject: [openvrml-develop] getting coordinates from ViewPoint- and
> > Sound-Nodes
> 
> > (1) How can I get the coordinates of the actual ViewPoint, i.e. 
> including 
> > the user navigation transformations, in the VRML-world 
> coordinate system 
> > (_not_ the OpenGL coordinate system)?
> > I have found some code concerning this in VrmlScene.render(). But 
> > how can I 
> > get the position out of the modelview-matrices used here? After a 
> > MV.getTransform(pos,...) the values in pos don't change even if I 
> > turn the 
> > scene around the viewer (or the viewer around the scene, which 
> > probably is 
> > more correctly). I also need some information (e.g. 
> view-up-vector) about 
> > the ViewPoint's orientation.
> 
> You go through the code "NodeBillboard::billboard_to_matrix(...)" or 
> "NodeLOD::render(..)". Here you will find how to get viewer 
> position w.r.t.
> local coordinate system. For your case don't inverse it.
>
If I am right, probably you can use local coordinate system to implement
sound node instead of going for world coordinate. 
 
Thanks,
 
Bose

RE: [openvrml-develop] getting coordinates from ViewPoint- and Sound-Nodes

[S. K. B. <bo...@pa...>]

> -----Original Message-----
> From: ope...@li...
> [mailto:ope...@li...]On Behalf Of -oli-
> Sent: Wednesday, April 10, 2002 8:46 PM
> To: ope...@li...
> Subject: [openvrml-develop] getting coordinates from ViewPoint- and
> Sound-Nodes

> (1) How can I get the coordinates of the actual ViewPoint, i.e. including
> the user navigation transformations, in the VRML-world coordinate system
> (_not_ the OpenGL coordinate system)?
> I have found some code concerning this in VrmlScene.render(). But
> how can I
> get the position out of the modelview-matrices used here? After a
> MV.getTransform(pos,...) the values in pos don't change even if I
> turn the
> scene around the viewer (or the viewer around the scene, which
> probably is
> more correctly). I also need some information (e.g. view-up-vector) about
> the ViewPoint's orientation.

You go through the code "NodeBillboard::billboard_to_matrix(...)" or
"NodeLOD::render(..)". Here you will find how to get viewer position w.r.t.
local coordinate system. For your case don't inverse it.

>
> (2) How can I get the coordinates of a Sound node in the VRML-world
> coordinate system?
> It seems to have something to do with the rc.getMatrix() method,
> but how do
> I get the position out of the matrix? Can I multiply the matrix with the
> position field of the Sound node?

Definitely yes.

Thanks,

Bose

[openvrml-develop] getting coordinates from ViewPoint- and Sound-Nodes

[-oli- <ol...@fr...>]

Hi, all!

To integrate OpenAL in OpenVMRL (see my former mails) I need answers to the 
following issues.
Btw - I'm using the "normal" cvs-version (not the rearchitecture-branch).

(1) How can I get the coordinates of the actual ViewPoint, i.e. including 
the user navigation transformations, in the VRML-world coordinate system 
(_not_ the OpenGL coordinate system)?
I have found some code concerning this in VrmlScene.render(). But how can I 
get the position out of the modelview-matrices used here? After a 
MV.getTransform(pos,...) the values in pos don't change even if I turn the 
scene around the viewer (or the viewer around the scene, which probably is 
more correctly). I also need some information (e.g. view-up-vector) about 
the ViewPoint's orientation.

(2) How can I get the coordinates of a Sound node in the VRML-world 
coordinate system?
It seems to have something to do with the rc.getMatrix() method, but how do 
I get the position out of the matrix? Can I multiply the matrix with the 
position field of the Sound node?

Thanks for answers,
hints are welcome!

	-oli-
	(Oliver Baum)

Re: [openvrml-develop] OpenAL sound support in OpenVRML

[Braden M. <br...@en...>]

On Tue, 2002-04-09 at 03:14, -oli- wrote:
> - I will use, develop and compile it under Windows (98 and 2k) with M$ 
> VisualC++ 6.0, and as I don't know much about makefiles, I will _not_ be 
> able to produce a patch which enables compiling with "--with-openal". I'm 
> inserting my own source with "#if use_openal" at the moment, so someone 
> else can adapt the makefiles.

Good; that will facilitate the configure option. Tom or I can help with
that when the time comes.

> At 20:43 08.04.2002 -0400, you wrote:
> >        * *Yes*, I would accept a patch for OpenAL-based audio support.
> >         * This support would be disabled by default. If someone wanted
> >           to build with it, they'd need to configure with
> >           "--with-openal" or somesuch.
> >         * If OpenVRML also had support for some other audio solution (I
> >           mentioned GStreamer before, and I still think it's our best
> >           bet under Linux), I would not be inclined to spend too much of
> >           *my own* energy maintaining multiple audio solutions in
> >           parallel.
> 
> That's okay.
> 
> >If you think I'm trying to steer you toward GStreamer instead of OpenAL,
> >you'd be right. However, I appreciate that you may have your own
> >motivation for wanting to use OpenAL, and I have no intention of
> >belaboring the issue beyond this posting. I appreciate that your work
> >*will* improve OpenVRML, even if it's not exactly what I'd do. :-)
> 
> I looked on the GStreamer website. It seems to be a powerful solution for 
> media processing, but there is no windows support (yet), so I cannot use it 
> at this time.

My thinking is that we'd use GStreamer on Linux, DirectX (or maybe
Quicktime) on Windows, and Quicktime on Mac. That probably sounds like
overkill for audio; and it would be, if we didn't have the MovieTexture
issue to solve as well. I think we'll need these dependencies *anyway*
for good MovieTexture support, and so it will be convenient to use their
facilities for streaming audio as well.

However, since your thesis is focused on audio, I can see how expanding
your work to a generalized streaming media solution would be a
distraction.

Best of luck to you, and I'll try to help however I can.

-- 
Braden McDaniel                           e-mail: <br...@en...>
<http://endoframe.com>                    Jabber: <br...@ja...>

Re: [openvrml-develop] OpenAL sound support in OpenVRML

[-oli- <ol...@fr...>]

Hi!

I will give some comments to my planned work on OpenVRML in this message:
- I need the OpenAL support in OpenVRML for my own puroposes, as I'm 
writing a diploma thesis about virtual acoustics.
- I will use, develop and compile it under Windows (98 and 2k) with M$ 
VisualC++ 6.0, and as I don't know much about makefiles, I will _not_ be 
able to produce a patch which enables compiling with "--with-openal". I'm 
inserting my own source with "#if use_openal" at the moment, so someone 
else can adapt the makefiles.
- I am using the OpenAL distribution from the Creative website (see Tom's 
mail).

At 20:43 08.04.2002 -0400, you wrote:
>        * *Yes*, I would accept a patch for OpenAL-based audio support.
>         * This support would be disabled by default. If someone wanted
>           to build with it, they'd need to configure with
>           "--with-openal" or somesuch.
>         * If OpenVRML also had support for some other audio solution (I
>           mentioned GStreamer before, and I still think it's our best
>           bet under Linux), I would not be inclined to spend too much of
>           *my own* energy maintaining multiple audio solutions in
>           parallel.

That's okay.

>If you think I'm trying to steer you toward GStreamer instead of OpenAL,
>you'd be right. However, I appreciate that you may have your own
>motivation for wanting to use OpenAL, and I have no intention of
>belaboring the issue beyond this posting. I appreciate that your work
>*will* improve OpenVRML, even if it's not exactly what I'd do. :-)

I looked on the GStreamer website. It seems to be a powerful solution for 
media processing, but there is no windows support (yet), so I cannot use it 
at this time.


Thanx for answering my questions!

Regards

         -oli-
         (Oliver Baum)

Re: [openvrml-develop] OpenAL sound support in OpenVRML

[Braden M. <br...@en...>]

On Mon, 2002-04-08 at 20:58, Thomas Flynn wrote:
> Just a few comments about this
> 
> Braden McDaniel wrote:
> 
> >On Mon, 2002-04-08 at 10:41, -oli- wrote:
> >
> >>As I wrote some weeks ago, I'm going to integrate OpenAL-support for the 
> >>sound in OpenVRML.
> >>
> >
> >Okay. I'm gonna be a bit more explicit than I was before in order to
> >ensure expectations are set appropriately. I don't want you to complete
> >this project and then be surprised by its reception.
> >
> >I don't think OpenAL is the best solution for audio in OpenVRML. At one
> >time it looked like it might be; however...
> >
> >        * OpenAL's primary user and developer (Loki) is no more.
> >        * There was never a (successful?) attempt to package OpenAL in a
> >          way that would be palatable to end-users and OS distributions.
> >          Even now, the OpenAL Web site directs persons looking for
> >          "1.0" to CVS. The project has reached 1.0, and there's *still*
> >          not a tarball.
> >
> >So OpenAL is difficult for end-users to install, and prospects for
> >continued support and development seem dim.
> >
> 
> Loki hasn't really been involved with OpenAL for quite some time outside 
> of hosting the site and CVS. Creative Labs has really been the main 
> driver behind it. Creative has made distributions available on their 
> developer site for Windows and Mac (see 
> http://developer.creative.com/scripts/DC_D&H_Games-Downloads.asp?opt=2) 
> and, from recent mail on the openal mailing list, has recently taken 
> over hosting the CVS repository as well...

I knew Creative had supported OpenAL, but I didn't realize they were
throwing significant development effort at it. That's good news.

The major problem I have with OpenAL being our primary audio solution is
the lack of a distribution tarball for which users can
"configure;make;make install". If development on OpenAL is continuing,
then there is hope for that to improve as well.

-- 
Braden McDaniel                           e-mail: <br...@en...>
<http://endoframe.com>                    Jabber: <br...@ja...>

Re: [openvrml-develop] OpenAL sound support in OpenVRML

[Thomas F. <tf...@us...>]

Just a few comments about this

Braden McDaniel wrote:

>On Mon, 2002-04-08 at 10:41, -oli- wrote:
>
>>As I wrote some weeks ago, I'm going to integrate OpenAL-support for the 
>>sound in OpenVRML.
>>
>
>Okay. I'm gonna be a bit more explicit than I was before in order to
>ensure expectations are set appropriately. I don't want you to complete
>this project and then be surprised by its reception.
>
>I don't think OpenAL is the best solution for audio in OpenVRML. At one
>time it looked like it might be; however...
>
>        * OpenAL's primary user and developer (Loki) is no more.
>        * There was never a (successful?) attempt to package OpenAL in a
>          way that would be palatable to end-users and OS distributions.
>          Even now, the OpenAL Web site directs persons looking for
>          "1.0" to CVS. The project has reached 1.0, and there's *still*
>          not a tarball.
>
>So OpenAL is difficult for end-users to install, and prospects for
>continued support and development seem dim.
>

Loki hasn't really been involved with OpenAL for quite some time outside 
of hosting the site and CVS. Creative Labs has really been the main 
driver behind it. Creative has made distributions available on their 
developer site for Windows and Mac (see 
http://developer.creative.com/scripts/DC_D&H_Games-Downloads.asp?opt=2) 
and, from recent mail on the openal mailing list, has recently taken 
over hosting the CVS repository as well...

>
>What this means:
>
>        * *Yes*, I would accept a patch for OpenAL-based audio support.
>        * This support would be disabled by default. If someone wanted
>          to build with it, they'd need to configure with
>          "--with-openal" or somesuch.
>
This sounds reasonable.

Tom

Re: [openvrml-develop] Considering OpenVRML for my project - Some questions

[Braden M. <br...@en...>]

On Mon, 2002-04-08 at 20:41, Reed Hedges wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> 
> On Monday, April 8, 2002, at 08:14 PM, Braden McDaniel wrote:
> 
> >
> >> Eventually I want to support Script
> >> nodes (which would affect my object structure).
> >
> > Aha... Now this is a whole 'nuther ball of wax. What kind of Script node
> > support are you looking for? If you mean *complete* Script node support,
> > then you need a whole VRML runtime engine, and OpenVRML definitely fits
> > the bill there.
> 
> Yeah, pretty complete. ROUTEs too.   What is the interface to Routes and 
> Script nodes?  I ran doxygen (by hand, after modifyiing Doxyfile.in -- 
> configure could not find my GL libs and aborted) but only noticed the 
> abstract ScriptObject parent class...

Check out the rearch branch. Tag is OpenVRML-REARCH_BRANCH. The doxygen
docs there are *much* better.

> > JavaScript is adequate, but incomplete. Check the task list. Java is
> > there, but nascent.
> 
> Yeah, JavaScript.
> 
> >> Can I build OpenVRML without any OpenGL rendering features and just use
> >> it's parsing and scripting features?
> >
> > Yes.
> 
> An option to configure?

No, but we need one. It's not hard; I'll do it before our next release.
(After the rearch branch merges back with the HEAD.)

> > It would be interesting to see a bridge between OpenVRML and some other
> > 3D runtime system. Such a project would definitely be helpful in
> > discovering what needs to be exposed in our API.
> 
> I won't have much time for this until the summer, but I'll be working on 
> it heavily then.  The VOS 3D stuff is informed  by VRML, but not really 
> based on it at all... so it will be a bit irritating bridging them :).  
> (It's not a scene graph per se, though the transformations are 
> hierarchical; we only have a few primatives and material 
> characteristics, but will be adding more.  And of course, it's always 
> the little things, right?)

The goal of the rearchitecture is to separate node implementations from
the core. We're not there yet; but the rearchitecture has made the
points of cohesion clear, and they will be eliminated one by one. I
mention this because it sounds like it will have significant
implications for the design of such a bridge.

> Also, I primarily work in Mac OSX.  Any work with OpenVRML on that 
> platform yet?  (One irritating thing is the weird places it puts some 
> libraries, such as OpenGL and GLUT :) It's really easy to "port" stuff 
> from Unix-ish platforms though, so I can do that pretty easily.

It was at least Mostly Working on OS X at some point. OS X is definitely
someplace we want to work well.

-- 
Braden McDaniel                           e-mail: <br...@en...>
<http://endoframe.com>                    Jabber: <br...@ja...>

Re: [openvrml-develop] OpenAL sound support in OpenVRML

[Braden M. <br...@en...>]

On Mon, 2002-04-08 at 10:41, -oli- wrote:
> As I wrote some weeks ago, I'm going to integrate OpenAL-support for the 
> sound in OpenVRML.

Okay. I'm gonna be a bit more explicit than I was before in order to
ensure expectations are set appropriately. I don't want you to complete
this project and then be surprised by its reception.

I don't think OpenAL is the best solution for audio in OpenVRML. At one
time it looked like it might be; however...

        * OpenAL's primary user and developer (Loki) is no more.
        * There was never a (successful?) attempt to package OpenAL in a
          way that would be palatable to end-users and OS distributions.
          Even now, the OpenAL Web site directs persons looking for
          "1.0" to CVS. The project has reached 1.0, and there's *still*
          not a tarball.

So OpenAL is difficult for end-users to install, and prospects for
continued support and development seem dim.

What this means:

        * *Yes*, I would accept a patch for OpenAL-based audio support.
        * This support would be disabled by default. If someone wanted
          to build with it, they'd need to configure with
          "--with-openal" or somesuch.
        * If OpenVRML also had support for some other audio solution (I
          mentioned GStreamer before, and I still think it's our best
          bet under Linux), I would not be inclined to spend too much of
          *my own* energy maintaining multiple audio solutions in
          parallel.

If you think I'm trying to steer you toward GStreamer instead of OpenAL,
you'd be right. However, I appreciate that you may have your own
motivation for wanting to use OpenAL, and I have no intention of
belaboring the issue beyond this posting. I appreciate that your work
*will* improve OpenVRML, even if it's not exactly what I'd do. :-)

> Here I have some questions regarding this:
> 
> (1) In which method(s) can I implement the assignment of the spatial 
> parameters (position, direction) of the sound to the OpenAL properties? 
> NodeSound::render() or NodeAudioClip::update() or NodeAudiClip::render(), 
> which doesn't exist yet.

That logic belongs in the Sound node.

> Regarding this, the method should be called 
> whenever the position of the Sound-Node or the ViewPoint-Node changes. 
> Besides that, also the time-dependend functionality in NodeSound::update() 
> should be maintained.

In the old architecture, that logic would belong in VrmlScene. In the
new architecture, it belongs in SoundClass.

> (2) The WAV-File is read totally into memory at the moment (see audio.h) 
> and then put chunk by chunk to the dsp-device (see NodeSound::update()). Is 
> this right?

As long as we aren't bothering with streaming, I think that's
acceptable. However, I'm not much of a "sound guy", so I might not know
what I'm talking about here.

-- 
Braden McDaniel                           e-mail: <br...@en...>
<http://endoframe.com>                    Jabber: <br...@ja...>

Re: [openvrml-develop] Considering OpenVRML for my project - Some questions

[Reed H. <re...@ze...>]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1


On Monday, April 8, 2002, at 08:14 PM, Braden McDaniel wrote:

>
>> Eventually I want to support Script
>> nodes (which would affect my object structure).
>
> Aha... Now this is a whole 'nuther ball of wax. What kind of Script node
> support are you looking for? If you mean *complete* Script node support,
> then you need a whole VRML runtime engine, and OpenVRML definitely fits
> the bill there.

Yeah, pretty complete. ROUTEs too.   What is the interface to Routes and 
Script nodes?  I ran doxygen (by hand, after modifyiing Doxyfile.in -- 
configure could not find my GL libs and aborted) but only noticed the 
abstract ScriptObject parent class...

> JavaScript is adequate, but incomplete. Check the task list. Java is
> there, but nascent.

Yeah, JavaScript.

>> Can I build OpenVRML without any OpenGL rendering features and just use
>> it's parsing and scripting features?
>
> Yes.

An option to configure?

> It would be interesting to see a bridge between OpenVRML and some other
> 3D runtime system. Such a project would definitely be helpful in
> discovering what needs to be exposed in our API.

I won't have much time for this until the summer, but I'll be working on 
it heavily then.  The VOS 3D stuff is informed  by VRML, but not really 
based on it at all... so it will be a bit irritating bridging them :).  
(It's not a scene graph per se, though the transformations are 
hierarchical; we only have a few primatives and material 
characteristics, but will be adding more.  And of course, it's always 
the little things, right?)

Also, I primarily work in Mac OSX.  Any work with OpenVRML on that 
platform yet?  (One irritating thing is the weird places it puts some 
libraries, such as OpenGL and GLUT :) It's really easy to "port" stuff 
from Unix-ish platforms though, so I can do that pretty easily.

thanks for the info!

reed

- --

Reed Hedges
re...@ze...
http://zerohour.net/~reed

Virtual Object System -- Internet Virtual Reality:
http://www.interreality.org

The owls are not what they seem.


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Re: [openvrml-develop] Considering OpenVRML for my project - Some questions

[Braden M. <br...@en...>]

On Mon, 2002-04-08 at 14:18, Reed Hedges wrote:
> Hi, I am looking for a VRML library.  I am probably going to use 
> OpenVRML, but have a few questions.
> Bascially what I want to do is parse a VRML file, and construct an 
> object structure based on that (using my own classes - See link below if 
> you're interested. I actually am thinking of doing two things, one is to 
> create a VOS structure from VRML, the other is a VRML model loader for 
> the Crystal Space 3D engine.).

To do that, it sounds like all you really need is a VRML parser. You
could rip the ANTLR grammar out of OpenVRML and modify it with your own
semantic actions instead of growing your own parser from scratch. But I
don't see an actual dependency on OpenVRML buying you any functionality
to achieve the ends you describe above.

> Eventually I want to support Script 
> nodes (which would affect my object structure).

Aha... Now this is a whole 'nuther ball of wax. What kind of Script node
support are you looking for? If you mean *complete* Script node support,
then you need a whole VRML runtime engine, and OpenVRML definitely fits
the bill there.

> Does it sound like OpenVRML will be useful to me?
> What is the current state of scripting, what is planned? How would I 
> communicate with scripts?

JavaScript is adequate, but incomplete. Check the task list. Java is
there, but nascent. Tom Flynn's been working on it, but I haven't had a
chance to play with it too much.

> Can I build OpenVRML without any OpenGL rendering features and just use 
> it's parsing and scripting features?

Yes.

It would be interesting to see a bridge between OpenVRML and some other
3D runtime system. Such a project would definitely be helpful in
discovering what needs to be exposed in our API.

-- 
Braden McDaniel                           e-mail: <br...@en...>
<http://endoframe.com>                    Jabber: <br...@ja...>

[openvrml-develop] Considering OpenVRML for my project - Some questions

[Reed H. <re...@ze...>]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1


Hi, I am looking for a VRML library.  I am probably going to use 
OpenVRML, but have a few questions.
Bascially what I want to do is parse a VRML file, and construct an 
object structure based on that (using my own classes - See link below if 
you're interested. I actually am thinking of doing two things, one is to 
create a VOS structure from VRML, the other is a VRML model loader for 
the Crystal Space 3D engine.).  Eventually I want to support Script 
nodes (which would affect my object structure).

Does it sound like OpenVRML will be useful to me?
What is the current state of scripting, what is planned? How would I 
communicate with scripts?
Can I build OpenVRML without any OpenGL rendering features and just use 
it's parsing and scripting features?


thanks a bunch

reed


- --

Reed Hedges
re...@ze...
http://zerohour.net/~reed

Virtual Object System -- Internet Virtual Reality:
http://www.interreality.org

The owls are not what they seem.


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[openvrml-develop] OpenAL sound support in OpenVRML

[-oli- <ol...@fr...>]

Hi, all!

As I wrote some weeks ago, I'm going to integrate OpenAL-support for the 
sound in OpenVRML.
Here I have some questions regarding this:

(1) In which method(s) can I implement the assignment of the spatial 
parameters (position, direction) of the sound to the OpenAL properties? 
NodeSound::render() or NodeAudioClip::update() or NodeAudiClip::render(), 
which doesn't exist yet. Regarding this, the method should be called 
whenever the position of the Sound-Node or the ViewPoint-Node changes. 
Besides that, also the time-dependend functionality in NodeSound::update() 
should be maintained.

(2) The WAV-File is read totally into memory at the moment (see audio.h) 
and then put chunk by chunk to the dsp-device (see NodeSound::update()). Is 
this right?


Btw: OpenAL (see http://www.openal.org/) is an OpenSource platform 
independend API for 3D-audio, developed by Loki Software, now maintained by 
Creative Labs.

As OpenAL uses a cones and VRML ellipsoids to define source directivity, 
I'm going to use OpenAL only for the location of the sound sources 
(spatialisation) and do the directivity stuff in OpenVRML "by hand".

Any tips/opinions/hints are welcome!

	-oli-
	(Oliver Baum)

Re: [openvrml-develop] Author of VrmlNodeLOD class

[Braden M. <br...@en...>]

On Wed, 2002-04-03 at 23:23, Christopher K. St. John wrote:
>  Double checking, yeah, I think that's about right. Hey,
> didn't all the Nodes used to be in their own file? That
> sure made it a lot easier to find things. 

Putting them in the same file means significantly shorter build times
when one of the files that all the node implementations need changes
(like "node.h"). But more importantly, code that shares implementation
details needs to be in the same translation unit; and it was in
anticipation of the node implementations sharing such details that they
were put in the same file. And if you look on the rearchitecture branch,
you'll find them doing just that.

-- 
Braden McDaniel                           e-mail: <br...@en...>
<http://endoframe.com>                    Jabber: <br...@ja...>

Re: [openvrml-develop] Author of VrmlNodeLOD class

[Christopher K. S. J. <ck...@di...>]

Damian McGuckin wrote:
> 
> I was interested in knowing who is the author of this 
>

 I wrote the recalcBSphere method, and the comment, but was
not the original author of the VrmlNodeLOD class. Well, I
definitely wrote the code, and I think I wrote that comment.
It's been a while, but it  sure reads like something I
would write. Abject apologies if it was somebody else.


> because I wish to
> have an optional method of load whereby the load is delayed
> until that level of the LOD is required to be rendered. 
>

 That would be good.
 

> I have having trouble figuring out what structure I need
> to manipulate to get this effect and any associated code
> I need to write to get it fully implemented.
> 

 Yes, I had the same problem. Thus the current code :-)
At the time I wrote it, I'm pretty sure I was thinking
that you'd need a pre-render-traversal step that updated
each LOD based on the current viewer position. You can't
really do it during the render-traversal, because you
might accidently cull something that was about to become
visible because of an LOD change. I think. It was a while
back. Does that sound right?

 Double checking, yeah, I think that's about right. Hey,
didn't all the Nodes used to be in their own file? That
sure made it a lot easier to find things. 


-- 
Christopher St. John ck...@di...
DistribuTopia http://www.distributopia.com

[openvrml-develop] Author of VrmlNodeLOD class

[Damian M. <da...@es...>]

Inside the code for VrmlNodeLOD, there are comments for delayed-load
inlines.

I was interested in knowing who is the author of this because I wish to
have an optional method of load whereby the load is delayed until that
level of the LOD is required to be rendered.  I would be curious to
discuss the issues.  I do not need the delayed load to be asynchronously
executed.  Actually, I explicitly do NOT want to done asynchronously as
I want it done only the first time it is rendered.

I have having trouble figuring out what structure I need to manipulate
to get this effect and any associated code I need to write to get it
fully implemented.

void
VrmlNodeLOD::recalcBSphere()
{
  //cout << "VrmlNodeLOD[" << this << "]::recalcBSphere()" << endl;
  d_bsphere.reset();

  // let's say our bsphere is the union of the bspheres of all the
  // levels. we could have said it was just the bsphere of the current
  // level, but the current level depends on the viewer position, and
  // we'd like to make the calculation idependent of that. we could do
  // some sort of trick where we reset the bsphere during render, but
  // that seems like overkill unless this simpler method proves to be
  // a bottleneck.
  //
  // hmm: just thought of a problem: one of the uses of the lod is to
  // switch in delayed-load inlines. this would necessarily switch
  // them in all at once. live with it for now.
  //
  for(int i=0; i<(int) d_level.getLength(); i++) {
    const VrmlBVolume* ci_bv = d_level.getElement(i)->getBVolume();
    d_bsphere.extend(*ci_bv);

  }
  this->setBVolumeDirty(false);
}

Many Thanks - Damian (McGuckin)

Pacific Engineering Systems International, 22/8 Campbell St, Artarmon NSW 2064
Ph:+61-2-99063377 .. Fx:+61-2-99063468   | unsolicited email not wanted here !
Views and opinions here are mine and not those of any past or present employer

Re: [openvrml-develop] Crash on Exit

[Braden M. <br...@en...>]

On Wed, 2002-04-03 at 10:02, Michael Schuldt wrote:
> At 09:55 03.04.2002 -0500, you wrote:
> >On Wed, 2002-04-03 at 09:18, Michael Schuldt wrote:
> > > Hi,
> > >
> > > the glut lookat and the win32lookat crashs on exit, the seg vault 
> > occurs at
> > > the removeBackground or removeViewpoint ... Method of VRMLScene.
> > > This is the reason why the destructor for the Class Image and anything 
> > else
> > > isn't called. But I need this to clean up any memory leaks caused
> > > from large movies. How can I solve this problem
> >
> >Are you getting this using the CVS version of OpenVRML?
> 
> Yes, the version is from 03.03.2002

Oh, yeah... I remember this now.

There are a few "issues" here, but the one that's really annoying is the
fact that VrmlNamespace must be deleted *after* the nodes in the
namespace have been deleted, and that's not happening.

This is going to be rather time consuming to fix, and I can't spare the
cycles to do it right now. I'll look at doing this after the
rearchitecture branch gets merged back into the main branch; but another
way to skin this cat is to implement refcounting of namespaces, which
needs to happen anyway.

-- 
Braden McDaniel                           e-mail: <br...@en...>
<http://endoframe.com>                    Jabber: <br...@ja...>

Re: [openvrml-develop] Crash on Exit

[Michael S. <Mic...@gm...>]

At 09:55 03.04.2002 -0500, you wrote:
>On Wed, 2002-04-03 at 09:18, Michael Schuldt wrote:
> > Hi,
> >
> > the glut lookat and the win32lookat crashs on exit, the seg vault 
> occurs at
> > the removeBackground or removeViewpoint ... Method of VRMLScene.
> > This is the reason why the destructor for the Class Image and anything 
> else
> > isn't called. But I need this to clean up any memory leaks caused
> > from large movies. How can I solve this problem
>
>Are you getting this using the CVS version of OpenVRML?

Yes, the version is from 03.03.2002

Micha.

Re: [openvrml-develop] Crash on Exit

[Braden M. <br...@en...>]

On Wed, 2002-04-03 at 09:18, Michael Schuldt wrote:
> Hi,
> 
> the glut lookat and the win32lookat crashs on exit, the seg vault occurs at 
> the removeBackground or removeViewpoint ... Method of VRMLScene.
> This is the reason why the destructor for the Class Image and anything else 
> isn't called. But I need this to clean up any memory leaks caused
> from large movies. How can I solve this problem

Are you getting this using the CVS version of OpenVRML?

-- 
Braden McDaniel                           e-mail: <br...@en...>
<http://endoframe.com>                    Jabber: <br...@ja...>

[openvrml-develop] Crash on Exit

[Michael S. <Mic...@gm...>]

Hi,

the glut lookat and the win32lookat crashs on exit, the seg vault occurs at 
the removeBackground or removeViewpoint ... Method of VRMLScene.
This is the reason why the destructor for the Class Image and anything else 
isn't called. But I need this to clean up any memory leaks caused
from large movies. How can I solve this problem

Thx in advance Micha

Re: [openvrml-develop] Image,Movietexture and FPS

[Braden M. <br...@en...>]

On Sun, 2002-03-31 at 04:05, Michael Schuldt wrote: 
> 
> >"frames per second" is one way of expressing the speed of a movie, but
> >it requires that you have a movie comprising frames. The speed of a
> >movie is the rate of play as expressed as a factor of the normal speed.
> >What if, for example, a MovieTexture was an SVG animation?
> 
> It's a good question, I think the initial value for Frames Per Second 
> should be 1.0.

1 frame per second? Why? 

> If SVG animation is a Movietexture the playback speed is controlled over 
> the speed,
> field and the fps value should be 1.0. Other opinions on this topic ??

Since the MovieTexture implementation shouldn't care about fps, I think
it stands to reason that there is no need to include that information in
the Image interface. The Image implementation should make the
translation between fps and speed where appropriate.

It looks like our MovieTexture implementation is currently very
frame-oriented; I don't think that's correct.

-- 
Braden McDaniel                           e-mail: <br...@en...>
<http://endoframe.com>                    Jabber: <br...@ja...>