POV-Ray : Newsgroups : povray.unofficial.patches : Lighting problems. Server Time
2 Sep 2024 08:19:35 EDT (-0400)
  Lighting problems. (Message 1 to 6 of 6)  
From: TonyB
Subject: Lighting problems.
Date: 17 Apr 2000 02:08:48
Message: <38faaa70@news.povray.org>
Hello. I need some help to finish the hallway scene I'm working on. Here's
the situation: I need for the lamps to cast light, and yet be
self-shadowing. I tried using looks_like, but they don't self-shadow. I
tried with light_groups, and got no where, since the lamp needs to be lit
from an external source to show up. I tried using rgbf <1,1,1,.1> and very
bright lights, but I get some strange banding on the bottom of the lightbulb
that no amount of max_trace_level seems to cure. What can I do? I want to
put lights in the center of the lightbulbs, but for the bulbs to be opaque
(non-transparent), slightly reflective and self-shadowing. Help. TIA


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From: Bob Hughes
Subject: Re: Lighting problems.
Date: 17 Apr 2000 02:45:12
Message: <38fab2f8$1@news.povray.org>
I think that usually calls for increasing the filter instead of lowering it,
then using high ambient or making the bulbs pigment more than 1 (rgbf<2,2,2,.9>
?) for it to show.  If I understand right.

Bob

"TonyB" <ben### [at] panamac-comnet> wrote in message
news:38faaa70@news.povray.org...
| Hello. I need some help to finish the hallway scene I'm working on. Here's
| the situation: I need for the lamps to cast light, and yet be
| self-shadowing. I tried using looks_like, but they don't self-shadow. I
| tried with light_groups, and got no where, since the lamp needs to be lit
| from an external source to show up. I tried using rgbf <1,1,1,.1> and very
| bright lights, but I get some strange banding on the bottom of the lightbulb
| that no amount of max_trace_level seems to cure. What can I do? I want to
| put lights in the center of the lightbulbs, but for the bulbs to be opaque
| (non-transparent), slightly reflective and self-shadowing. Help. TIA
|
|


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From: Bob Hughes
Subject: Re: Lighting problems.
Date: 17 Apr 2000 03:02:35
Message: <38fab70b@news.povray.org>
I just tried a quick check of what I said to do and it sort of fails if nothing
is in the background but seems okay if there is.  Then again it tends to
increase any object color in the background.  Here's what I ended up with:

union {
 light_source {0,1.5}
 sphere {<0,0,0>,1 texture {
 pigment {rgbf<1.5,1.5,1.5,.5>}
  finish {ambient .5 reflection .5}}
 }
}

plane {y,-1 pigment {rgb<1,1,0>}}


| I think that usually calls for increasing the filter instead of lowering it,
| then using high ambient or making the bulbs pigment more than 1
(rgbf<2,2,2,.9>
| ?) for it to show.  If I understand right.
|
| Bob
|
| "TonyB" <ben### [at] panamac-comnet> wrote in message
| news:38faaa70@news.povray.org...
| | Hello. I need some help to finish the hallway scene I'm working on. Here's
| | the situation: I need for the lamps to cast light, and yet be
| | self-shadowing. I tried using looks_like, but they don't self-shadow. I
| | tried with light_groups, and got no where, since the lamp needs to be lit
| | from an external source to show up. I tried using rgbf <1,1,1,.1> and very
| | bright lights, but I get some strange banding on the bottom of the lightbulb
| | that no amount of max_trace_level seems to cure. What can I do? I want to
| | put lights in the center of the lightbulbs, but for the bulbs to be opaque
| | (non-transparent), slightly reflective and self-shadowing. Help. TIA
| |
| |
|
|


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From: Nathan Kopp
Subject: Re: Lighting problems.
Date: 17 Apr 2000 10:14:06
Message: <38fb1c2e@news.povray.org>
TonyB <ben### [at] panamac-comnet> wrote...
> I want to
> put lights in the center of the lightbulbs, but for the bulbs to be opaque
> (non-transparent), slightly reflective and self-shadowing. Help. TIA

Does the entire bulb have to be self shadowing?  I assume that you only need
the light to go through the frosted-glass part, and that the frosted-glass
part doesn't have to cast any shadows.  If this is the case, just make that
specific part of the bulb "no_shadow" with a high ambient.  This will make
it glow and be opaque but allow light to pass through it.  Alternatively, if
you use megapov, you can turn on double-illuminate and use diffuse instead
of ambient.  If you don't put "no_shadow" in the other parts of the bulb,
then they will cast shadows.  I would assume that, because the frosted-glass
is acting as a source of illumination, it would be so bright as to make any
self-shadowing hardly visible.

-Nathan


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From: TonyB
Subject: Re: Lighting problems.
Date: 17 Apr 2000 11:48:40
Message: <38fb3258@news.povray.org>
Thank you Bob and Nathan. The problem was finally fixed by consulting Bob's
lightbulb. Using media, I was able to mask any transparency, while still
letting the light through.


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From: Bob Hughes
Subject: Re: Lighting problems.
Date: 17 Apr 2000 20:34:31
Message: <38fbad97@news.povray.org>
There's an even easier way maybe.  I neglected to mention using phong 1
phong_size 0.1 before, would probably saturate the object enough while still
being fully transparent to the inside light source.  However having tried it
there seems to be problems in getting any reflection or other texturing to show.

Bob

"TonyB" <ben### [at] panamac-comnet> wrote in message
news:38fb3258@news.povray.org...
| Thank you Bob and Nathan. The problem was finally fixed by consulting Bob's
| lightbulb. Using media, I was able to mask any transparency, while still
| letting the light through.
|
|


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