POV-Ray : Newsgroups : povray.general : Anti-vampires Server Time
5 Nov 2024 22:21:16 EST (-0500)
  Anti-vampires (Message 1 to 6 of 6)  
From: Greg M  Johnson
Subject: Anti-vampires
Date: 27 Mar 1999 14:25:54
Message: <36fd30c2.0@news.povray.org>
I want to make an object that will cast a reflection but is "invisible"
to my camera "directly".
Is this possible?

I want to move the camera along with an object.  I want to be able to
see the object's reflection, and am finding that I want the camera
closer to the "middle" of my object than a few micro units "above" it.


Post a reply to this message

From: Lance Birch
Subject: Re: Anti-vampires
Date: 27 Mar 1999 21:52:13
Message: <36fd995d.0@news.povray.org>
Um, don't get me wrong here, but if it's invisible to the camera directly,
how do you expect it to cast reflections?  And, I don't think that you mean
*cast* reflections do you?  Do you mean, it can be reflected by other
objects, but you can't see it normally...  Like, you can see if reflected in
an objects surface, but you can't see it in the scene.  In which case I
think it would require a little reprogramming of POV-Ray...

(or some clever image editing ;-)

--
Lance.


---
For the latest 3D Studio MAX plug-ins, images and much more, go to:
The Zone - http://come.to/the.zone


Post a reply to this message

From: Bob Hughes
Subject: Re: Anti-vampires
Date: 28 Mar 1999 03:17:38
Message: <36FDE59C.D45AE230@aol.com>
If anything the reverse may be possible. Ha! That was a bit of sick
humor, sorry.
You or somebody has asked this before, I'm sure.
Trying negative color and reflection values will get you nowhere I
think, I've tried quite a few things like that anyhow and never have I
seen a object disappear AND be in a mirror, far as I know.
Considering the object has got to be transparent, the mirror would need
an opposing reflection.
Now I have to eat my words, because I tested it out just now carefully.
Take a render of the following:

// BEGIN
#version 3.1

camera
{
  location  <0.5, 0.5, -4.0>
  direction 1.5*z
  right     4/3*x
  look_at   <0.0, 0.0,  0.0>
}

sky_sphere
{
  pigment
  {
    gradient y
    color_map { [0.0 color blue 0.5] [1.0 color rgb 1] }
  }
}

light_source
{
  0*x // light's position (translated below)
  color red 1.0  green 1.0  blue 1.0  // light's color
  translate <-30, 30, -30>
}

// ----------------------------------------
plane { z, 2 pigment {color rgb -1} finish {reflection 1} rotate 5*y
translate 9*x}

sphere { 0.0, 1 texture {pigment {rgbt 1}} }

//END

Lance Birch wrote:
> 
> Um, don't get me wrong here, but if it's invisible to the camera directly,
> how do you expect it to cast reflections?  And, I don't think that you mean
> *cast* reflections do you?  Do you mean, it can be reflected by other
> objects, but you can't see it normally...  Like, you can see if reflected in
> an objects surface, but you can't see it in the scene.  In which case I
> think it would require a little reprogramming of POV-Ray...
> 
> (or some clever image editing ;-)
> 
> --
> Lance.
> 
> ---
> For the latest 3D Studio MAX plug-ins, images and much more, go to:
> The Zone - http://come.to/the.zone

-- 
 omniVERSE: beyond the universe
  http://members.aol.com/inversez/homepage.htm
 mailto:inv### [at] aolcom?Subject=PoV-News


Post a reply to this message

From: Bob Hughes
Subject: Re: Anti-vampires
Date: 28 Mar 1999 03:35:30
Message: <36FDE9D0.3019C3F7@aol.com>
Silly me, I neglected to consider max_trace_level. Use 6 instead of
default 5 and it vanishes from the mirror also. Though it was
interesting for a few moments anyway.


Bob Hughes wrote:
> 
> If anything the reverse may be possible. Ha! That was a bit of sick
> humor, sorry.
> You or somebody has asked this before, I'm sure.
> Trying negative color and reflection values will get you nowhere I
> think, I've tried quite a few things like that anyhow and never have I
> seen a object disappear AND be in a mirror, far as I know.
> Considering the object has got to be transparent, the mirror would need
> an opposing reflection.
> Now I have to eat my words, because I tested it out just now carefully.
> Take a render of the following:
> 
> // BEGIN
> #version 3.1
> 
> camera
> {
>   location  <0.5, 0.5, -4.0>
>   direction 1.5*z
>   right     4/3*x
>   look_at   <0.0, 0.0,  0.0>
> }
> 
> sky_sphere
> {
>   pigment
>   {
>     gradient y
>     color_map { [0.0 color blue 0.5] [1.0 color rgb 1] }
>   }
> }
> 
> light_source
> {
>   0*x // light's position (translated below)
>   color red 1.0  green 1.0  blue 1.0  // light's color
>   translate <-30, 30, -30>
> }
> 
> // ----------------------------------------
> plane { z, 2 pigment {color rgb -1} finish {reflection 1} rotate 5*y
> translate 9*x}
> 
> sphere { 0.0, 1 texture {pigment {rgbt 1}} }
> 
> //END
> 
> Lance Birch wrote:
> >
> > Um, don't get me wrong here, but if it's invisible to the camera directly,
> > how do you expect it to cast reflections?  And, I don't think that you mean
> > *cast* reflections do you?  Do you mean, it can be reflected by other
> > objects, but you can't see it normally...  Like, you can see if reflected in
> > an objects surface, but you can't see it in the scene.  In which case I
> > think it would require a little reprogramming of POV-Ray...
> >
> > (or some clever image editing ;-)
> >
> > --
> > Lance.
> >
> > ---
> > For the latest 3D Studio MAX plug-ins, images and much more, go to:
> > The Zone - http://come.to/the.zone
> 
> --
>  omniVERSE: beyond the universe
>   http://members.aol.com/inversez/homepage.htm
>  mailto:inv### [at] aolcom?Subject=PoV-News

-- 
 omniVERSE: beyond the universe
  http://members.aol.com/inversez/homepage.htm
 mailto:inv### [at] aolcom?Subject=PoV-News


Post a reply to this message

From: Lance Birch
Subject: Re: Anti-vampires
Date: 28 Mar 1999 03:54:45
Message: <36fdee55.0@news.povray.org>
he he he

--
Lance.


---
For the latest 3D Studio MAX plug-ins, images and much more, go to:
The Zone - http://come.to/the.zone


Post a reply to this message

From: Rune S  Johansen
Subject: Re: Anti-vampires
Date: 28 Mar 1999 09:22:37
Message: <36fe3b2d.0@news.povray.org>
Lance Birch wrote:
>Um, don't get me wrong here, but if it's invisible to the camera directly,
>how do you expect it to cast reflections?  And, I don't think that you mean
>*cast* reflections do you?  Do you mean, it can be reflected by other
>objects, but you can't see it normally...  Like, you can see if reflected
in
>an objects surface, but you can't see it in the scene.  In which case I
>think it would require a little reprogramming of POV-Ray...
>
>(or some clever image editing ;-)
<snip>

If you just want it to be reflected in a planear mirror you
could in some cases just make the whole scene twice. One actual
and one flipped for the "reflection".
If you want it to be reflected in other shapes, this doesn't
work, though.

Greetings,

Rune S. Johansen
http://hjem.get2net.dk/rsj


Post a reply to this message

Copyright 2003-2023 Persistence of Vision Raytracer Pty. Ltd.