>So far I am not overly impressed by
>it but opinions are subject to change.


It really shouldn't impress you much more than phong or specular. It's just
a better way of doing it.

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"TonyB" <ben### [at] panamac-comnet> wrote in message
news:389840af@news.povray.org...
>
> [Ken wrote:]
> >
> >So far I am not overly impressed by
> >it but opinions are subject to change.
>
>
> It really shouldn't impress you much more than
> phong or specular. It's just a better way of doing it.

I guess it's a testiment to the old methods that a more realistic method
doesn't show much different.  I'll make new .inc files anyway... it's like
"new, improved Tide"... your wash comes out looking the same, but you buy it
anyways.

Eric
--------------------
http://www.datasync.com/~ericfree
--------------------
"The whole problem with the world is that fools and fanatics are always so
certain of themselves, but wiser people so full of doubts."
--Bertrand Russel

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This doesn't look good for the 'blinn' model of highlighting.  At least in that
previous textures will suffer greatly in the conversion.  I like the old style
you show here, the new style is all specular and no texture.

Bob

"Eric Freeman" <eri### [at] datasynccom> wrote in message
news:3897c2ed@news.povray.org...
| Here's a couple of images to go with my post to unofficial.patches.

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"Bob Hughes" <omn### [at] hotmailcom?subject=PoV-News:> wrote in message
news:3898ad88@news.povray.org...
>
> This doesn't look good for the 'blinn' model of
> highlighting.  At least in that previous textures
> will suffer greatly in the conversion.  I like the
> old style you show here, the new style is all
> specular and no texture.

Don't give up hope.  After more experimentation (and a six pack of Bud), I
think I'm beginning to see the differences between the specular and the
Blinn methods.  Attached are two images of two metal textures, the only
difference being Blinn highlighting and adding the "reflect_metallic"
statement to the textures.  Note that the two images look very similar.  It
seems that the pigment and the angle have a lot to do with the way it looks.
These two textures also appear in Part Two and look very different.  I'm
still experimenting with Blinn and hope to have Blinn versions of
"metals.inc" and "golds.inc" soon.

Eric
--------------------
http://www.datasync.com/~ericfree
--------------------
"The whole problem with the world is that fools and fanatics are always so
certain of themselves, but wiser people so full of doubts."
--Bertrand Russel

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Attachments:
Download 'mega_metal_test1.jpg' (37 KB) Download 'mega_metal_test2.jpg' (25 KB)

Preview of image 'mega_metal_test1.jpg'

Preview of image 'mega_metal_test2.jpg'

Here's a demo scene, the first one with specular and the second with Blinn.
Note the brass cylinder on the left and the copper cube in the top left.

Eric
--------------------
http://www.datasync.com/~ericfree
--------------------
"The whole problem with the world is that fools and fanatics are always so
certain of themselves, but wiser people so full of doubts."
--Bertrand Russel

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Attachments:
Download 'old_metal_demo.jpg' (88 KB) Download 'mega_metal_demo.jpg' (80 KB)

Preview of image 'old_metal_demo.jpg'

Preview of image 'mega_metal_demo.jpg'

Hopefully the vertical flip was intended :-)
This does show there can be a conversion from one to the other and still get a
similar texture as before.  I can't decide what the differences in highlighting
alone actually is.  Seems the blinn is more diffused, the reflect_metallic
obviously playing a considerable role in color.

Bob

"Eric Freeman" <eri### [at] datasynccom> wrote in message
news:3898be4f@news.povray.org...
| Attached are two images of two metal textures, the only
| difference being Blinn highlighting and adding the "reflect_metallic"
| statement to the textures.  Note that the two images look very similar.  It
| seems that the pigment and the angle have a lot to do with the way it looks.
| These two textures also appear in Part Two and look very different.  I'm
| still experimenting with Blinn and hope to have Blinn versions of
| "metals.inc" and "golds.inc" soon.

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I think you should try 'reflect_metallic' in the 'specular' version just to
compare directly across then.

Bob

"Eric Freeman" <eri### [at] datasynccom> wrote in message
news:3898bf99@news.povray.org...
| Here's a demo scene, the first one with specular and the second with Blinn.
| Note the brass cylinder on the left and the copper cube in the top left.

Post a reply to this message

"Bob Hughes" <omn### [at] hotmailcom?subject=PoV-News:> wrote in message
news:3898cbf2@news.povray.org...
>
> I think you should try 'reflect_metallic' in the
> 'specular' version just to compare directly
> across then.

Here it is.  But since the "#version unofficial MegaPov 0.4;" statement must
come before the "#declare FinishName = ...." statement this image also uses
the new 0.4 features that share the "reflection" keyword with official POV.
As you can see, this looks just like the Mega 0.4 version, so I guess it is
these features and not blinn that make the big difference.

Eric
--------------------
http://www.datasync.com/~ericfree
--------------------
"The whole problem with the world is that fools and fanatics are always so
certain of themselves, but wiser people so full of doubts."
--Bertrand Russel

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Attachments:
Download 'old_metal_demox.jpg' (32 KB)

Preview of image 'old_metal_demox.jpg'

It takes some scrutinizing, I can see the slight differences, although I haven't
even tried this myself yet and so don't know if the float values would be the
same or not.  I guess if there were a "difference" it is the highlight diffusion
being sometimes more, sometimes less, depending on the angle of light source to
the object surfaces.  In a similar way to how angle dependant reflection works
maybe.  Or did I read that somewhere?

Bob

"Eric Freeman" <eri### [at] datasynccom> wrote in message
news:3898fd13@news.povray.org...
| "Bob Hughes" <omn### [at] hotmailcom?subject=PoV-News:> wrote in message
| news:3898cbf2@news.povray.org...
| >
| > I think you should try 'reflect_metallic' in the
| > 'specular' version just to compare directly
| > across then.
|
| Here it is.  But since the "#version unofficial MegaPov 0.4;" statement must
| come before the "#declare FinishName = ...." statement this image also uses
| the new 0.4 features that share the "reflection" keyword with official POV.
| As you can see, this looks just like the Mega 0.4 version, so I guess it is
| these features and not blinn that make the big difference.
|
| Eric
| --------------------
| http://www.datasync.com/~ericfree
| --------------------
| "The whole problem with the world is that fools and fanatics are always so
| certain of themselves, but wiser people so full of doubts."
| --Bertrand Russel
|
|
|
|
|

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"Bob Hughes" <omn### [at] hotmailcom?subject=PoV-News:> wrote in message
news:38994a25@news.povray.org...
>
> It takes some scrutinizing, I can see the slight
> differences,

Slight differences can make a picture.  Often small area lights, a slight
focal blur and a little light fading can make an average picture
outstanding.

> although I haven't even tried this myself yet and
> so don't know if the float values would be the
> same or not.

I didn't use the same values... I just tried to get the two textures to have
similar highlight properties.  For example, the original F_MetalC, D and E
have the same amount of specular (0.80) but my blinn versions have 2.0, 1.9
and 2.1.

> I guess if there were a "difference" it is the
> highlight diffusion being sometimes more,
> sometimes less, depending on the angle of
> light source to the object surfaces.

It also seems like the highlight is grayer and reflects less (but that could
be changes in the "reflection" property, which has been changed in Mega
0.4).  I'll be doing some more experimenting, making textures that don't use
reflection.

Eric
--------------------
http://www.datasync.com/~ericfree
--------------------
"The whole problem with the world is that fools and fanatics are always so
certain of themselves, but wiser people so full of doubts."
--Bertrand Russel

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