So povray's textures are supposed to be 3D, and indeed the patterns are
demonstrably three-dimensional, however they do not seem to be sampled for the
inside of an object.

So I guess my question is: Why not?

I've seen people do some amazing things with procedural textures, but I've never
seen a fully volumetric texture in povray.

By all means, prove me wrong.

Regards,
A.D.B.

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Anthony D. Baye <Sha### [at] spamnomorehotmailcom> wrote:
> So povray's textures are supposed to be 3D, and indeed the patterns are
> demonstrably three-dimensional, however they do not seem to be sampled for the
> inside of an object.

> So I guess my question is: Why not?

POV-Ray renders *surfaces*.

-- 
                                                          - Warp

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Le 03/01/2015 10:13, Warp a écrit :
> Anthony D. Baye <Sha### [at] spamnomorehotmailcom> wrote:
>> So povray's textures are supposed to be 3D, and indeed the patterns are
>> demonstrably three-dimensional, however they do not seem to be sampled for the
>> inside of an object.
> 
>> So I guess my question is: Why not?
> 
> POV-Ray renders *surfaces*.
> 
Sampling 3D is done with media (and there is three kind of them), inside
surface.

Post a reply to this message

"Anthony D. Baye" <Sha### [at] spamnomorehotmailcom> wrote:
> So povray's textures are supposed to be 3D, and indeed the patterns are
> demonstrably three-dimensional, however they do not seem to be sampled for the
> inside of an object.
>
> So I guess my question is: Why not?
>
> I've seen people do some amazing things with procedural textures, but I've never
> seen a fully volumetric texture in povray.
>
> By all means, prove me wrong.
>
> Regards,
> A.D.B.

You are wrong. In my search for methods to make earthlike planets, I once tried
media instead of isosurfaces - and it worked. Just pust the pigment in a media
container. You can also control the density of the media in the same way.

-Nekar Xenos-

Post a reply to this message

> So povray's textures are supposed to be 3D, and indeed the patterns are
> demonstrably three-dimensional, however they do not seem to be sampled for the
> inside of an object.
>
> So I guess my question is: Why not?
>
> I've seen people do some amazing things with procedural textures, but I've never
> seen a fully volumetric texture in povray.
>
> By all means, prove me wrong.
>
> Regards,
> A.D.B.
>
>

To get volumetric textures, you need to use some media. That media also 
need to get enough samples to realy show the structure.

Try this:

box{-5 5 hollow pigment{rgbt 1}
interior{
	media{
		emission 0.2
		samples 15
		density{bozo}
		}
	}
}

You can replace the bozo pattern with any pattern you want. Some need 
more samples.


Alain

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Le_Forgeron <jgr### [at] freefr> wrote:
> Le 03/01/2015 10:13, Warp a écrit :
> > Anthony D. Baye <Sha### [at] spamnomorehotmailcom> wrote:
> >> So povray's textures are supposed to be 3D, and indeed the patterns are
> >> demonstrably three-dimensional, however they do not seem to be sampled for the
> >> inside of an object.
> >
> >> So I guess my question is: Why not?
> >
> > POV-Ray renders *surfaces*.
> >
> Sampling 3D is done with media (and there is three kind of them), inside
> surface.


Obviously media are the way to go. A good way here may be the use of df3-files.
Bill Pokorny has given the link to an interesting visualisation tool just some
days ago

http://news.povray.org/povray.general/thread/%3C54a2dc7e%241%40news.povray.org%3E/

Of course one must generate or obtain the df3-files first. But this is another
story...

Best regards,
Michael

Post a reply to this message

"MichaelJF" <mi-### [at] t-onlinede> wrote:
> Le_Forgeron <jgr### [at] freefr> wrote:
> > Le 03/01/2015 10:13, Warp a écrit :
> > > Anthony D. Baye <Sha### [at] spamnomorehotmailcom> wrote:
> > >> So povray's textures are supposed to be 3D, and indeed the patterns are
> > >> demonstrably three-dimensional, however they do not seem to be sampled for the
> > >> inside of an object.
> > >
> > >> So I guess my question is: Why not?
> > >
> > > POV-Ray renders *surfaces*.
> > >
> > Sampling 3D is done with media (and there is three kind of them), inside
> > surface.
>
>
> Obviously media are the way to go. A good way here may be the use of df3-files.
> Bill Pokorny has given the link to an interesting visualisation tool just some
> days ago
>
> http://news.povray.org/povray.general/thread/%3C54a2dc7e%241%40news.povray.org%3E/
>
> Of course one must generate or obtain the df3-files first. But this is another
> story...
>
> Best regards,
> Michael

There's a key difference between media and textures. Textures have finishes.

As for Warps glib response about povray only rendering surfaces: that hasn't
been true since media was added. Subsurface scattering is also b.d. not on the
surface.  Why can't textures be sampled for the interior as well?

A.D.B.

Post a reply to this message

"Anthony D. Baye" <Sha### [at] spamnomorehotmailcom> wrote:
> "MichaelJF" <mi-### [at] t-onlinede> wrote:
> > Le_Forgeron <jgr### [at] freefr> wrote:
> > > Le 03/01/2015 10:13, Warp a écrit :
> > > > Anthony D. Baye <Sha### [at] spamnomorehotmailcom> wrote:
> > > >> So povray's textures are supposed to be 3D, and indeed the patterns are
> > > >> demonstrably three-dimensional, however they do not seem to be sampled for
the
> > > >> inside of an object.
> > > >
> > > >> So I guess my question is: Why not?
> > > >
> > > > POV-Ray renders *surfaces*.
> > > >
> > > Sampling 3D is done with media (and there is three kind of them), inside
> > > surface.
> >
> >
> > Obviously media are the way to go. A good way here may be the use of df3-files.
> > Bill Pokorny has given the link to an interesting visualisation tool just some
> > days ago
> >
> > http://news.povray.org/povray.general/thread/%3C54a2dc7e%241%40news.povray.org%3E/
> >
> > Of course one must generate or obtain the df3-files first. But this is another
> > story...
> >
> > Best regards,
> > Michael
>
> There's a key difference between media and textures. Textures have finishes.
>
> As for Warps glib response about povray only rendering surfaces: that hasn't
> been true since media was added. Subsurface scattering is also b.d. not on the
> surface.  Why can't textures be sampled for the interior as well?
>
> A.D.B.

Maybe I misunderstood what you meant. Can you show me an example of such a
texture?

Post a reply to this message

"Nekar Xenos" <nomail@nomail> wrote:
> > > > > Anthony D. Baye <Sha### [at] spamnomorehotmailcom> wrote:
> > > > >> So povray's textures are supposed to be 3D, and indeed the patterns are
> > > > >> demonstrably three-dimensional, however they do not seem to be sampled for
the
> > > > >> inside of an object.
> > > > >
> > > > >> So I guess my question is: Why not?
>
> Maybe I misunderstood what you meant. Can you show me an example of such a
> texture?

Jumping in here...

Only way I can imagine this being possible is to recreate or duplicate a
multitude of scaled objects that have a texture applied to all. I'm fairly sure
this subject has been discussed many times in the past.

And the usefulness could only work for textures or materials with some
transparency, otherwise there would be nothing to see of the internal portions.

Lacking any transparent parts this could already be accomplished with CSG of
objects. In other words, once again using only surfaces as usual. So I would
think some kind of transparency is needed for such an idea to be worthwhile.

isosurface for patterns alone is what I was thinking might be thought of as 3D
pattern object. The missing component being complete texturing, not simply a
pattern.

Skipping over that idea I rendered a basic sphere, scaled incrementally smaller
123 times, with checker pattern and specular highlight (while also making small
changes to those for each re-scale) and got the rendering shown at:

http://www.0mniverse.com/povray/3Dcheckerpatterntexture.jpg

The key to this problem is rendering all components of a texture throughout the
ray trace space. Maybe it could be done, even if it meant something like the way
I tried to show here. Of course, I found render time increased by hundreds of
times so that would be a problem.

I don't know if this is what's being asked about. Basic idea seems to be about
texturing patterns without confines of object surfaces and that's something
completely different(?).

Post a reply to this message

"Nekar Xenos" <nomail@nomail> wrote:
> "Anthony D. Baye" <Sha### [at] spamnomorehotmailcom> wrote:
> > "MichaelJF" <mi-### [at] t-onlinede> wrote:
> > > Le_Forgeron <jgr### [at] freefr> wrote:
> > > > Le 03/01/2015 10:13, Warp a écrit :
> > > > > Anthony D. Baye <Sha### [at] spamnomorehotmailcom> wrote:
> > > > >> So povray's textures are supposed to be 3D, and indeed the patterns are
> > > > >> demonstrably three-dimensional, however they do not seem to be sampled for
the
> > > > >> inside of an object.
> > > > >
> > > > >> So I guess my question is: Why not?
> > > > >
> > > > > POV-Ray renders *surfaces*.
> > > > >
> > > > Sampling 3D is done with media (and there is three kind of them), inside
> > > > surface.
> > >
> > >
> > > Obviously media are the way to go. A good way here may be the use of df3-files.
> > > Bill Pokorny has given the link to an interesting visualisation tool just some
> > > days ago
> > >
> > >
http://news.povray.org/povray.general/thread/%3C54a2dc7e%241%40news.povray.org%3E/
> > >
> > > Of course one must generate or obtain the df3-files first. But this is another
> > > story...
> > >
> > > Best regards,
> > > Michael
> >
> > There's a key difference between media and textures. Textures have finishes.
> >
> > As for Warps glib response about povray only rendering surfaces: that hasn't
> > been true since media was added. Subsurface scattering is also b.d. not on the
> > surface.  Why can't textures be sampled for the interior as well?
> >
> > A.D.B.
>
> Maybe I misunderstood what you meant. Can you show me an example of such a
> texture?

I'll admit that I'm having problems finding good examples of what I'm after.
Most uses of volumetric textures in games seem to be about doing smoke effects,
which is what we have media for, or hair effects, which are better handled in
other ways.

What I was hoping to accomplish is to create a believable compound material with
solid and transparent parts.

With the current system, when you look through the transparent parts of a
texture, you see the texture on the back surface of the object, with nothing
inside.

What I'd like to see is the internal boundaries between transparent and opaque
parts of the texture.

The way I imagine this happening is that, as you trace along a ray, you sample
the texture continuously at intervals, until you hit an opaque pixel, or the
blended result of your previous samples is "reasonably opaque".

this method could even account for things like flaws or air pockets in a
transparent material without having to resort to a csg object or isosurface.

Admittedly, I have no experience with this sort of programming, so I'm just
theorizing how it could work without thinking about things like overhead.

As it is, the only way I can think of to achieve the effect I'd like is to use a
compound object with each part having its own texture.

I can't think of any way to get this effect using simple layered textures, but
I'm not that much of an artist.  If anyone has examples of this sort of thing
using the current system, I'd love to see them.

Regards,
A.D.B.

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