POV-Ray : Newsgroups : povray.binaries.images : Glowing text problem Server Time
30 Jul 2024 12:20:59 EDT (-0400)
  Glowing text problem (Message 1 to 3 of 3)  
From: Jörg 'Yadgar' Bleimann
Subject: Glowing text problem
Date: 27 Jan 2012 16:23:10
Message: <4f2315be@news.povray.org>
Hi(gh)!

Still fiddling with the include files exhibition room at Port 
Whatmough's PoV-Ray museum... I want to have the glass lid of the 
exhibition table to include a text display which glows in its own light 
(and is also glowing when used together with radiosity, so ambient 1 is 
no option). I tried emissive media, but found out that it fades to 
invisibility against a white background.

Simply increasing the red component gives weird results... attached here 
are four attempts:

1. rgbft <1, 0, 0, 0.5, 0.5>, ambient 1
2. rgbft <10, 0, 0, 0.5, 0.5>, default ambient
3. rgbft <10, 0, 0, 0, 0.5> default ambient
4. rgbft <10, 0, 0, 0.5, 0> default ambient

What did I misunderstand?

See you in Khyberspace!

Yadgar


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Attachments:
Download '20111219a_pwres.jpg' (51 KB) Download '20120127a_pwres.jpg' (64 KB) Download '20120127b_pwres.jpg' (51 KB) Download '20120127c_pwres.jpg' (67 KB)

Preview of image '20111219a_pwres.jpg'
20111219a_pwres.jpg

Preview of image '20120127a_pwres.jpg'
20120127a_pwres.jpg

Preview of image '20120127b_pwres.jpg'
20120127b_pwres.jpg

Preview of image '20120127c_pwres.jpg'
20120127c_pwres.jpg


 

From: Cousin Ricky
Subject: Re: Glowing text problem
Date: 28 Jan 2012 10:40:00
Message: <web.4f241696786f8b3b78641e0c0@news.povray.org>
=?ISO-8859-1?Q?J=F6rg_=27Yadgar=27_Bleimann?= <yaz### [at] gmxde> wrote:
>  I want to have the glass lid of the
> exhibition table to include a text display which glows in its own light
> (and is also glowing when used together with radiosity, so ambient 1 is
> no option).

Are you using POV-Ray 3.6 or 3.7?

If 3.6, then you can set #default { finish { ambient 0 } } in general, and set
ambient as high as you like in the finish{} of individual glowing objects.

If 3.7, have you tried finish { emission 1 }?


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From: Christian Froeschlin
Subject: Re: Glowing text problem
Date: 30 Jan 2012 21:36:22
Message: <4f2753a6$1@news.povray.org>


> ambient 1 is no option

if you mean ambient is set to 0 when rendering with 3.7 RC3:

-> emission 1 should work with radiosity

if you heard ambient should not be used in textures
when using radiosity in 3.6:

-> if the object is actually intended to be glowing, this is
    perfectly fine, it emits light and radiosity will consider it
    appropriately.

> I tried emissive media, but found out that it fades to invisibility 
> against a white background.

If your background is fully white it means it emits the maximum
amount of light that can be recognized by the eye or camera viewing
the scene. It will be impossible to see a glow in front of it. Any
text displayed before this background will be visible because it
is darker / absorbing. Considering this may help you to figure
out what end result you are actually aiming at.

> Simply increasing the red component gives weird results

I don't fully understand this either but if your filter
value times the color value exceeds 1.0 some weirdness is
to be expected (however, if this physically unrealistic
value is allowed, I'd have expected it to amplify red
light passing through it, which should never result in
a white background turning blueish).


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