In article <3ea0f666$1@news.povray.org>,
 Simon Adameit <sim### [at] gaussschule-bsde> wrote:

> Normally glass is modeled with thickness and not just as one surface so 
> slope or object pattern might be better.

Neither of those will be of any help in making one-way glass. If you 
make a box with one side dark and the other side light, you will either 
see the dark side directly or through the light side. I'm not sure how 
you plan to use the slope pattern...I think it is idependant of the side 
of the surface it is evaluated at.

Anyway, in a one-way glass window, you are unlikely to be able to tell 
the difference between thick glass and single-surface glass. With smart 
lighting and reflection values, you should be able to get an acceptable 
effect, otherwise using interior_texture or actually changing the 
texture depending on the camera location is probably the best way to go.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

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Conserve_energy could be helpfull here don't you think?
the part of light which is reflected is not transmitted.
Inside building is darker than outside so less light comes from inside.
Isn't it how it works?

Marc


de news: cja### [at] netplexaussieorg...
> In article <3ea0f666$1@news.povray.org>,
>  Simon Adameit <sim### [at] gaussschule-bsde> wrote:
>
> > Normally glass is modeled with thickness and not just as one surface so
> > slope or object pattern might be better.
>
> Neither of those will be of any help in making one-way glass. If you
> make a box with one side dark and the other side light, you will either
> see the dark side directly or through the light side. I'm not sure how
> you plan to use the slope pattern...I think it is idependant of the side
> of the surface it is evaluated at.
>
> Anyway, in a one-way glass window, you are unlikely to be able to tell
> the difference between thick glass and single-surface glass. With smart
> lighting and reflection values, you should be able to get an acceptable
> effect, otherwise using interior_texture or actually changing the
> texture depending on the camera location is probably the best way to go.
>
> --
> Christopher James Huff <cja### [at] earthlinknet>
> http://home.earthlink.net/~cjameshuff/
> POV-Ray TAG: chr### [at] tagpovrayorg
> http://tag.povray.org/

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Christopher James Huff wrote:
> In article <3ea0f666$1@news.povray.org>,
>  Simon Adameit <sim### [at] gaussschule-bsde> wrote:
> 
> 
>>Normally glass is modeled with thickness and not just as one surface so 
>>slope or object pattern might be better.
> 
> 
> Neither of those will be of any help in making one-way glass. If you 
> make a box with one side dark and the other side light, you will either 
> see the dark side directly or through the light side. I'm not sure how 
> you plan to use the slope pattern...I think it is idependant of the side 
> of the surface it is evaluated at.

Ah, I didn't think of that. But one could use the slope or object 
pattern in the interior texture.

> Anyway, in a one-way glass window, you are unlikely to be able to tell 
> the difference between thick glass and single-surface glass. With smart 
> lighting and reflection values, you should be able to get an acceptable 
> effect, otherwise using interior_texture or actually changing the 
> texture depending on the camera location is probably the best way to go.
> 

In a one-way glass window you wouldn't need the effect.

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In article <3ea1b251@news.povray.org>,
 Simon Adameit <sim### [at] gaussschule-bsde> wrote:

> Ah, I didn't think of that. But one could use the slope or object 
> pattern in the interior texture.

Wha...? Why not just use the interior texture? And what possible use 
would the object pattern have?


> > Anyway, in a one-way glass window, you are unlikely to be able to tell 
> > the difference between thick glass and single-surface glass. With smart 
> > lighting and reflection values, you should be able to get an acceptable 
> > effect, otherwise using interior_texture or actually changing the 
> > texture depending on the camera location is probably the best way to go.
> 
> In a one-way glass window you wouldn't need the effect.

The effect is a way to achieve one-way glass! The idea is that you use 
interior_texture to get one-way glass, not that you use one-way glass to 
avoid using interior_texture.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

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In article <3ea192b1$1@news.povray.org>,
 "Marc Jacquier" <jac### [at] wanadoofr> wrote:

> Conserve_energy could be helpfull here don't you think?
> the part of light which is reflected is not transmitted.
> Inside building is darker than outside so less light comes from inside.

I don't think it would be much help in this particular case, but it's 
worth checking out. The idea's that the window is partially reflective, 
has a dark room on one side and a light room on the other. From the dark 
side, the transmitted light washes out the reflected light. From the 
light side, it is the other way around.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

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Christopher James Huff wrote:
> 
> > Wha...?

A one-way glass window does only make sense if you will be able to see 
it from both sides and if you see it from both sides you will be able to 
tell the difference between a thick glass and a single-surface glass 
thus you need a way to archieve one-way thick glass which with interior 
texture alone wont work, the interior texture needs to be transparent 
but the outside texture only needs to be transparent on one side which 
you can archieve with the object or slope pattern.

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In article <3ea7e2b2@news.povray.org>,
 Simon Adameit <sim### [at] gaussschule-bsde> wrote:

> A one-way glass window does only make sense if you will be able to see 
> it from both sides

Right. Otherwise you could just change the texture.


> and if you see it from both sides

Say, from a mirror in the room on the "subject" room, with the camera in 
the "observer" room.


> you will be able to tell the difference between a thick glass and a 
> single-surface glass 

Uh...why? You would still need a close look at it.


> thus you need a way to archieve one-way thick glass which with interior 
> texture alone wont work, the interior texture needs to be transparent 
> but the outside texture only needs to be transparent on one side which 
> you can archieve with the object or slope pattern.

Well, as I've been saying, you can probably get a reasonable one-way 
effect by good lighting. But I don't see how the slope pattern can help 
here. Are you using the object pattern to only silver one side of the 
glass? That's a little overkill in flexibility, and gradient would 
probably be as fast, but it would work.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

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Christopher James Huff wrote:
> In article <3ea7e2b2@news.povray.org>,
> 
> 
> Uh...why? You would still need a close look at it.
> 

It's not about being able to see both surfaces but about the rays not 
ending up parallel. You could use a lower ior to compensate for this but 
this will make fresnel reflection look all wrong.

> Well, as I've been saying, you can probably get a reasonable one-way 
> effect by good lighting. 

lightning?

>But I don't see how the slope pattern can help 

The same way object or gradient(if the window is flat) pattern can help.

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In article <3ea807ba@news.povray.org>,
 Simon Adameit <sim### [at] gaussschule-bsde> wrote:

> It's not about being able to see both surfaces but about the rays not 
> ending up parallel. 

Parallel? Rays that start out parallel will stay parallel.


> You could use a lower ior to compensate for this but 

Ah, you are thinking of using ior. With a single-surface window, you 
would obviously not use an ior.


> this will make fresnel reflection look all wrong.

Why are you using fresnel reflection?


> > Well, as I've been saying, you can probably get a reasonable one-way 
> > effect by good lighting. 
> 
> lightning?

No, lighting.


> >But I don't see how the slope pattern can help 
> 
> The same way object or gradient(if the window is flat) pattern can help.

I now see how you were applying the object pattern, but not the slope 
pattern. What are you using it for?

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

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Christopher James Huff wrote:
> In article <3ea807ba@news.povray.org>,
>  Simon Adameit <sim### [at] gaussschule-bsde> wrote:
> 
> 
>>It's not about being able to see both surfaces but about the rays not 
>>ending up parallel. 
> 
> 
> Parallel? Rays that start out parallel will stay parallel.

When you use ior the ray that enters the glass should be parallel to the 
one leaving the glass (in case of a flat window) which is not the case 
with a single surface. I think I'm so used to using ior and fresnel 
reflection with glass that I didn't even think of not doing so and 
simply using a single-surface as the refraction probably wont be visible 
anyways.

>>lightning?
> 
> No, lighting
> 

I know that you ment lighting and also wanted to say that but I dont 
know what you ment? (Does that make sense?)

> I now see how you were applying the object pattern, but not the slope 
> pattern. What are you using it for?
> 

For the same purpose. Make one side of the glass (the outside texture on 
one side) non transparent, highly reflective, or whatever...

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