POV-Ray : Newsgroups : povray.general : WRL format??? Server Time
1 Nov 2024 00:26:21 EDT (-0400)
  WRL format??? (Message 1 to 9 of 9)  
From: Hokus Pokus
Subject: WRL format???
Date: 11 Oct 2000 21:37:07
Message: <39e515c3@news.povray.org>
I am wanting to build avatars and worlds for use in CyberTown online
community.
Can PovRay renderings be exported or saved in the .wrl format?
Thanks for any help


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From: Ken
Subject: Re: WRL format???
Date: 11 Oct 2000 21:39:15
Message: <39E5150B.76AEC3CD@pacbell.net>
Hokus Pokus wrote:

> Can PovRay renderings be exported or saved in the .wrl format?

No.

-- 
Ken Tyler


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From: Hokus Pokus
Subject: Thanks Ken
Date: 11 Oct 2000 21:43:15
Message: <39e51733@news.povray.org>
Thanks Ken





"Ken" <tyl### [at] pacbellnet> wrote in message
news:39E5150B.76AEC3CD@pacbell.net...
>
>
> Hokus Pokus wrote:
>
> > Can PovRay renderings be exported or saved in the .wrl format?
>
> No.
>
> --
> Ken Tyler


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From: Peter Popov
Subject: Re: WRL format???
Date: 12 Oct 2000 19:16:04
Message: <hnqauso5a1v282u7f93r641qoetvp37ca8@4ax.com>
On Wed, 11 Oct 2000 18:34:03 -0700, Ken <tyl### [at] pacbellnet> wrote:

>
>
>Hokus Pokus wrote:
>
>> Can PovRay renderings be exported or saved in the .wrl format?
>
>No.

You may, however, render environment maps using either a cylindrical,
true spherical (from MegaPOV) or six renders with a perspective camera
and map these on a cylinder, sphere or box, respectively. Of course
this will only work as QTVR but it's still better than nothing.


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] usanet
TAG      e-mail : pet### [at] tagpovrayorg


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From: Rev  Bob 'Bob' Crispen
Subject: Re: WRL format???
Date: 20 Oct 2000 18:47:00
Message: <8FD3BD8DFrevbob@204.213.191.228>
The kindly Rev. overheard pet### [at] usanet (Peter Popov) saying on
12 Oct 2000: 

>On Wed, 11 Oct 2000 18:34:03 -0700, Ken <tyl### [at] pacbellnet> wrote:
>
>>
>>
>>Hokus Pokus wrote:
>>
>>> Can PovRay renderings be exported or saved in the .wrl format?
>>
>>No.
>
>You may, however, render environment maps using either a cylindrical,
>true spherical (from MegaPOV) or six renders with a perspective
>camera and map these on a cylinder, sphere or box, respectively. Of
>course this will only work as QTVR but it's still better than
>nothing. 

Yeah, VRML's just a *teensy* bit different from QTVR.  The former is 
geometry-based, and the latter is photo-based.

The only thing that's worth translating at all, imho, is triangle 
meshes.  It should be fairly easy with perl or awk or a little piece of 
C to turn POVRay triangle meshes into VRML IndexedFaceSets.
-- 
Rev. Bob "Bob" Crispen
crispen at hiwaay dot net

If a cow laughed, would milk come out her nose?


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From: Peter Popov
Subject: Re: WRL format???
Date: 20 Oct 2000 19:45:56
Message: <0bm1vsk1l4u8r058a13g5tt5qprc835ho8@4ax.com>
On 20 Oct 2000 18:47:00 -0400, rev### [at] therectory (Rev. Bob 'Bob'
Crispen) wrote:

>Yeah, VRML's just a *teensy* bit different from QTVR.  The former is 
>geometry-based, and the latter is photo-based.
>
>The only thing that's worth translating at all, imho, is triangle 
>meshes.  It should be fairly easy with perl or awk or a little piece of 
>C to turn POVRay triangle meshes into VRML IndexedFaceSets.

Doesn't the latest 3DWin read/write from/to Warp's compressed mesh
format?


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] usanet
TAG      e-mail : pet### [at] tagpovrayorg


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From: Rev  Bob 'Bob' Crispen
Subject: Re: WRL format???
Date: 20 Oct 2000 22:02:07
Message: <8FD3D47B5revbob@204.213.191.228>
The kindly Rev. overheard pet### [at] usanet (Peter Popov) saying on
20 Oct 2000: 

>>Yeah, VRML's just a *teensy* bit different from QTVR.  The former is
>>geometry-based, and the latter is photo-based.
>>
>>The only thing that's worth translating at all, imho, is triangle 
>>meshes.  It should be fairly easy with perl or awk or a little piece
>>of C to turn POVRay triangle meshes into VRML IndexedFaceSets.
>
>Doesn't the latest 3DWin read/write from/to Warp's compressed mesh
>format?

Yeah, but I thought Warp's compressed mesh format was also binary 
compressed.  Was I mistaken?  I'm embarrassed to say I haven't looked at 
it yet.

Somehow I have this weird feeling that we're talking about two different 
things.  Please bear with me, on the off chance you don't already know 
this much better than I do.

The .wrl file format is for Virtual Reality Modeling Language (VRML).  
It's a text format (to be specific, UTF8).

The original question was, unless that bad acid is kicking in again, can 
you convert from POVRay to VRML?

Ken answered no, and I agreed with him in the main.  While you do have 
cones, spheres, cylinders, and blocks in both VRML and POVRay, VRML has 
no toruses (or Tauruses), no CSG, no blobs, no computed surfaces, and on 
and on.

But there's two ways to build POVRay scenes: by hand and with a 
modeler.  And since modelers often product lots of triangles and smooth 
triangles, I just wanted to point out that you could, in that subset of 
POVRay scenes, convert a trangle mesh or smooth triangle mesh to a VRML 
IndexedFaceSet, provided you were willing to write a little text 
manipulation program to play around with the text in the POVRay file.  
You could even do it by hand in a text editor if you were far more 
careful and patient than I am.

In the case of triangles, you'd simply take out all the coordinates, 
stick them in an array, and then create coordinate indexes 0 1 2, 3 4 5, 
and so on (in the VRML syntax, each coordIndex ends with a -1 as a 
punctuation mark).

In the case of smooth triangles, you'd take the normal fields and create 
an array of them as well, setting normalPerVertex true.  That ought to 
look pretty good.

But in any case, it's just plain text manipulation, and all the 
information is already there in the .pov or .inc file.  You don't have 
to triangulate or do anything fancy since POV declares one triangle at a 
time.

Now that I think of it, you'd have to change the signs of all the Z 
values.  I'll have to think for a minute about what that means for the 
normals.

If it turns out Warp's compressed format is actually text and lets you 
specify coordinate arrays, coordinate indexes, and indexed arrays of 
vertex or face normals, than I'm the one who doesn't know what's going 
on, and it should be miles easier to convert from that format to VRML.

As to using a cylinder to project an image on in VRML, I've seen it done 
on the Mars Rover images, and it was awful.  You get all the slow 
download speed of bitmap graphics *and* you get crummy looking 
rendering, because VRML has got to project the bits into the viewing 
plane of the browser, which is invariably at the wrong distance and at 
the wrong angle for them to show up very well.  Or will be, as soon as 
the visitor to the VRML world moves.

Now I see what you were talking about when you mentioned projecting the 
scene on a cylinder and using it in QTVR.  If you use SkyPaint 
<http://www.wasabisoft.com/>, you could in fact create a LivePicture 
scene.  I don't know about QTVR itself, though.
-- 
Rev. Bob "Bob" Crispen
crispen at hiwaay dot net

Grabel's Law: 2 is not equal to 3 - not even for very large
values of 2.


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From: Peter Popov
Subject: Re: WRL format???
Date: 21 Oct 2000 15:39:23
Message: <1tr3vsk8v66m793qfffc51t5i37mt3efjd@4ax.com>
On 20 Oct 2000 22:02:07 -0400, rev### [at] therectory (Rev. Bob 'Bob'
Crispen) wrote:

>Yeah, but I thought Warp's compressed mesh format was also binary 
>compressed.  Was I mistaken?  I'm embarrassed to say I haven't looked at 
>it yet.

No, it's a text format. That's why Chris Colefax's macros can read it.

>The .wrl file format is for Virtual Reality Modeling Language (VRML).  
>It's a text format (to be specific, UTF8).

I know, I've played with it a little.

>The original question was, unless that bad acid is kicking in again, can 
>you convert from POVRay to VRML?

And the answer is that you can, but only meshes.

>If it turns out Warp's compressed format is actually text and lets you 
>specify coordinate arrays, coordinate indexes, and indexed arrays of 
>vertex or face normals, than I'm the one who doesn't know what's going 
>on, and it should be miles easier to convert from that format to VRML.

Warp's compressed mesh is just what you described - vertex
coordinates, normals, vertex & normal indices and then UV coordinates
(if necessary), all in plain vanilla ASCII.

>As to using a cylinder to project an image on in VRML, I've seen it done 
>on the Mars Rover images, and it was awful.  You get all the slow 
>download speed of bitmap graphics *and* you get crummy looking 
>rendering, because VRML has got to project the bits into the viewing 
>plane of the browser, which is invariably at the wrong distance and at 
>the wrong angle for them to show up very well.  Or will be, as soon as 
>the visitor to the VRML world moves.

Just an idea anyway. I never said it would work like a charm :)


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] usanet
TAG      e-mail : pet### [at] tagpovrayorg


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From: Rev  Bob 'Bob' Crispen
Subject: Re: WRL format???
Date: 21 Oct 2000 20:51:50
Message: <8FD4C6D0Frevbob@204.213.191.228>
The kindly Rev. overheard pet### [at] usanet (Peter Popov) saying on
21 Oct 2000: 

>>The .wrl file format is for Virtual Reality Modeling Language
>>(VRML).  It's a text format (to be specific, UTF8).
>
>I know, I've played with it a little.

I'll say you have!  Christ, why didn't you tug on my coat or something?  
Sorry, Peter, I must be growing senile.

>Warp's compressed mesh is just what you described - vertex
>coordinates, normals, vertex & normal indices and then UV coordinates
>(if necessary), all in plain vanilla ASCII.

I found the URL in the backlogs of p.b.utilities, so I'll check it out.  
Looks like Warp reinvented the IndexedFaceSet (which also can have a 
TextureCoordinate field)!  See, I told you VRML had some good ideas.

;-)

Actually, I think either Rikk Carey (Inventor) or Eric Haines (nff) may 
have done it first.  One of these days somebody will write a history of 
3D file formats and some of us will be the only ones who buy it.

Speaking of 3D file formats, I've been into the innards of .3dmf 
recently.  Does somebody want to tell me what the heck the edges are for 
in the TriMesh?

>>As to using a cylinder to project an image on in VRML, I've seen it
>>done on the Mars Rover images, and it was awful.  You get all the
>>slow download speed of bitmap graphics *and* you get crummy looking 
>>rendering, because VRML has got to project the bits into the viewing
>>plane of the browser, which is invariably at the wrong distance and
>>at the wrong angle for them to show up very well.  Or will be, as
>>soon as the visitor to the VRML world moves.
>
>Just an idea anyway. I never said it would work like a charm :)

What makes LivePicture and QTVR work so well is that at a particular 
distance the pixels in the texture line up one for one with the pixels 
in the viewing window.  So just keep the distance fixed between the 
viewpoint and the surrounding cylinder of image (that's one reason 
you're stuck in the middle of a QTVR scene), add a little pixel blending 
to depixelate to either side of the center of the frustum, and the user 
will do the rest as he rotates to look at the area of interest.  The 
user thinks the image is sharp because he's looking at the center, which 
*is* sharp.
-- 
Rev. Bob "Bob" Crispen
crispen at hiwaay dot net

In three words I can sum up everything I've learned about life:
it goes on.


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