Tom Stone <tom### [at] teliacom> wrote:
: And I'm not sure that it is fair to call it a "standard". No Mesh2 file have
: ever been produced on a Mac.

  Render the SDL raytracer tutorial example which comes with the documentation
and there you are.

: I'm just commenting that the documentation seems to imply that
: I can use it, when several hours of searching on the Internet reveals
: that I can't.

  Why couldn't you? I used it in that tutorial without the need of any third
party program. I just used it and period.

  If the documentation says that mesh2 is *mainly* intended for file
conversions, that doesn't mean that you couldn't use it directly (as I did).

  It's the exact same thing as with bicubic patches: They are mainly intended
for third party programs. However, nothing stops you from using the directly.

-- 
#macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
],13),8)-3,10>#end blob{N(array[6]{11117333955,
7382340,3358,3900569407,970,4254934330},0)}//                     - Warp -

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Warp wrote:

>   Render the SDL raytracer tutorial example which comes with the documentation
> and there you are.

I've just seen it. It's an amazing piece of work! I couldn't understand even half
of it, but it definitely shows the power of POV.

>
> : I'm just commenting that the documentation seems to imply that
> : I can use it,

>  Why couldn't you? I used it in that tutorial without the need of any third
> party program. I just used it and period.

True. Thanks for your help.
I guess that the reason for my misunderstanding is that I read Gilles Tran's
tutorial on how to use Poser figures in POV-Ray, in which he says that he needed
converters to get the models into the Mesh2 format. But I realize now that he
wrote that tutorial before the release of this Beta. Since, as you say, there
isn't any need for third party software anymore, I guess that there is a big
chance that Gilles will update his tutorial to show how to do the same
internally.

I've written Joseph Strout (developer of Meshwork) and asked if he could add .obj
to Mesh2 conversion in his software, but I'll write to him again and let him know
that it isn't necessary anymore.

Once again, thanks for your kind help! This is a great forum!

Sincerely,
Tom Stone

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Tom Stone <tom### [at] teliacom> wrote:
: But I realize now that he
: wrote that tutorial before the release of this Beta. Since, as you say, there
: isn't any need for third party software anymore

  Anymore? There has never been any need. The mesh2 is practically identical
in POV3.5 than it was in MegaPov. Nothing has changed.

-- 
#macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
],13),8)-3,10>#end blob{N(array[6]{11117333955,
7382340,3358,3900569407,970,4254934330},0)}//                     - Warp -

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Tom Stone wrote:

> I guess that there is a big
> chance that Gilles will update his tutorial to show how to do the same
> internally.

Well, perhaps it's still unclear, but the problem hasn't changed with 3.5.

- mesh2 objects are text files that can be written by hand or by Povray itself.
They're not platform-specific and this has always be the case for meshes or bicubic
patches. Using them like this, however, is limited to simple objects or to objects
that can be generated algorithmically.

- if you have a file written in an other format, such as obj or 3DS, you'll need a
converter and presently these converters are mostly for Windows. Until a Mac
programmer writes a converter native to Mac, or until developers of commercial apps
start implementing mesh2 exports, the situation is not going to change. AFAIK, the
current workaround is still to use one of the few Mac apps that exports to Povray's
regular mesh (Amapi does it, I don't know about others). However, with Poser being
also a Mac application and mesh2 being an official POV-Ray feature, this is more
likely to happen than before.

Now, in the specific case of Poser, I guess that someone with a good understanding of
both the obj files exported by Poser and the mesh2 format could write a converter in
POV script. Not the most efficient solution though.

G.

--

**********************
http://www.oyonale.com
**********************
Graphic experiments
Pov-ray gallery

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Gilles Tran <tra### [at] inapginrafr> wrote:

> - if you have a file written in an other format, such as obj or 3DS,
> you'll need a converter and presently these converters are mostly for
> Windows. Until a Mac programmer writes a converter native to Mac, or until
> developers of commercial apps start implementing mesh2 exports, the
> situation is not going to change.

If code (C or C++) for such converters is available it shouldn't be too
hard to port it for Mac users. So, if anyone knows of free converter
code, we might have a look at it.



-- 
e-mail:sme### [at] skynetbe

http://users.skynet.be/smellenbergh

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Gilles Tran wrote:

>  AFAIK, the
> current workaround is still to use one of the few Mac apps that exports to Povray's
> regular mesh (Amapi does it, I don't know about others).

Hello Gilles, thanks for answering. I think that Amapi only exports the geometry and
not
UV-textures, thats at least the case with the free 4.15 version.

> Now, in the specific case of Poser, I guess that someone with a good understanding
of
> both the obj files exported by Poser and the mesh2 format could write a converter in
> POV script. Not the most efficient solution though.

Are you really sure about that?
Warp said opposite, in a rather forceful way that felt pretty intimidating.
According to him, it seemed like no one of us needed any converters,
and that I was more or less an idiot for believing so. And Ken have
expressed similar sentiments.

This is confusing.

Thanks anyway Gilles. I love your stories and pictures!
Tom

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Tom Stone wrote:
> 
> Gilles Tran wrote:
> 
> Are you really sure about that?
> Warp said opposite, in a rather forceful way that felt pretty intimidating.
> According to him, it seemed like no one of us needed any converters,
> and that I was more or less an idiot for believing so. And Ken have
> expressed similar sentiments.

No, you didn't understand Warp (or Ken). Gilles is right.


Another way to explain things:

mesh2 is a POV object. Anybody can use a POV object. Take
your editor, write the text file, that's it. bicubic_patch
and mesh also are objects. Go use them.

But... mesh, mesh2 and bicubic_patch are sooo tedious to
code by hand. Just an infinite list of numbers. Almost no
human could write them by hand. At least not a useful number
of them.

So... you need a program to write them! Programs do "dumb"
things quickly, and generating several thousands of meshes
and bicubic_patch values is their job.

Now... how will the program create the objects? The program
can't "guess" them. It can use an algorithm to create
them: Someone could create a program that takes a point and
a radius as a parameter and outputs a pseudo-sphere made of
thousands of triangles. That's what most modelers do, indeed.

Or... The program could read a Poser object, decode it, and
write thousands of meshes to represent the object. That's a
converter.

Warp... has done a POV script that outputs mesh2 objects.
I have not looked at it, so I don't know what it uses as
input. But clearly, from what Warp and Gilles wrote, Warp's
script doesn't read Poser objects (or whatever objects).

So... you still need a converter from Whatever(tm) Object
format to POV mesh2 objects. That's your personal need.
But other people (like Warp) have personal uses of mesh2
that differ from yours. And those personal uses can work
on many platforms, as Warp's script do.

BTW: You might have misunderstood, in the previous messages,
some informations about the converters. Basically, every
Mac application programmer was waiting for a definitive
POV version before offering to output "mesh2" objects. Once
the beta is over, it is likely that software packages like
Poser will support it (if not, ask them).


Hope this finally clears things out.

-- 
Adrien Beau - adr### [at] freefr - http://adrien.beau.free.fr
 Mes propos n'engagent que moi et en aucun cas mes employeurs

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smellenbergh wrote:

> If code (C or C++) for such converters is available it shouldn't be too
> hard to port it for Mac users. So, if anyone knows of free converter
> code, we might have a look at it.

Thomas Baier has the source code for 3dto3d available for download.
http://www.stmuc.com/thbaier/download.html
but I don't understand exactly if it's free.

FlyerFX has a free specific obj (Poser) to Povray utility.
http://people.tamu.edu/~sfg2113/poserayhelp.htm
No source given but if someone ask him kindly...

G.
--

**********************
http://www.oyonale.com
**********************
Graphic experiments
Pov-ray gallery

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smellenbergh wrote:

> If code (C or C++) for such converters is available it shouldn't be too
> hard to port it for Mac users. So, if anyone knows of free converter
> code, we might have a look at it.

Hi,
That sounds wonderful!

Though, you might want to know that I got an answer from Joe Strout today:
==========================

>However, I seem to remember that you wrote somewhere that you might
>possibly add support for POV-Ray's new Mesh2 format that can handle UV
>mapping. Well, the POV-team have finally released a Beta version of
>version 3.5 which can be downloaded from:
>
>http://mac.povray.org/download/beta.html

Woo!  I've been waiting for this.  I thought I was on the list to
receive an announcement when it was released, but apparently not --
this is the first I've heard of it.

>I don't know how complicated it is, but I would really want to be able
>to convert Poser.obj files to be able to use it in POV-ray,

I've got a start on a general-purpose 3D model format converter.  I
certainly would include OBJ import/export and POV-ray export.
But  I'll see if I can get something into Meshwork soon, too.

>If this is unsuitable for Meshwork, then perhaps a such converter could
>be made possible as a tutorial for RealBasic?

It's a bit too complex of a thing for a tutorial, I think.

Cheers,
- Joe
,------------------------------------------------------------------.
|    Joseph J. Strout         Check out the Mac Web Directory:     |
|    joe### [at] stroutnet           http://www.macwebdir.com/            |
`------------------------------------------------------------------'
==================================

Since Joe seems to have started the work on a converter, it might not be
necessary for you to do all this work also.
However, I guess that Joe could have use for your expert knowledge. Is it okey
if I send your email address to him?

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Tom Stone <tom### [at] teliacom> wrote:
: According to him, it seemed like no one of us needed any converters,
: and that I was more or less an idiot for believing so.

  I have never said anything like that.
  What I said is that you don't *necessarily* need an external program in
order to create a mesh2, as you can create one yourself.
  The mesh2 is not some kind of inaccessible binary encrypted file which can
only be created by sophisticated programs which mere mortals can't understand.
The mesh2 format is just a plain and easily readable ascii format which you
can write yourself by hand if you wish. It's not even very cryptic, but quite
logical. It's also absolutely platform-independent; it doesn't contain anything
that would depend on a certain system.
  Of course this doesn't mean it's easy. As meshes just contain vertex points
and a whole surface is built up with triangles using those vertex points, it's
near impossible to make anything really complex just by writing numbers by
hand.
  There are mainly three ways of creating a mesh/mesh2:

  - You just write one by hand by entering coordinates. Usually this is
limited to extremely simple shapes such as boxes because it becomes just too
difficult to do anything more complicated (forget about making a human face
by entering vertex coordinates by hand).

  - You can algorithmically generate (with POV-Ray SDL) a mesh. With this you
can do a lot more complicated things with lots of triangles. One simple example
is to create a spherical surface with thousands of triangles.
  Here you basically just write a POV-Ray script which creates the mesh using
math.

  - You can use a third-party program which has the ability of writing a
triangle mesh in POV-Ray format. What the program does is just to generate
the mesh in POV-Ray format (the exact same format which you can write by
hand) from some input (usually a mesh in another non-pov format).

-- 
#macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
],13),8)-3,10>#end blob{N(array[6]{11117333955,
7382340,3358,3900569407,970,4254934330},0)}//                     - Warp -

Post a reply to this message