 |
|
|
|
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Hi,
Why is it when I make the ambient higher then 1 of an object to starts
to loose it's color i.e. it gets white. Is that the way it should work?
It is certainly not what I was expecting, I just thought that the object
would "emit" more light in radiosity scene's with higher ambient values.
TIA
Thomas
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
"Thomas" <tho### [at] gmx net> wrote in message news:3BCD724B.EDDA1BB0@gmx.net...
> Hi,
>
> Why is it when I make the ambient higher then 1 of an object to starts
> to loose it's color i.e. it gets white. Is that the way it should work?
> It is certainly not what I was expecting, I just thought that the object
> would "emit" more light in radiosity scene's with higher ambient values.
>
Dunno, but thinking about it, this has always bugged me as well...
(sorry, that wasn't much help, was it?)
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Thomas wrote:
>
> Why is it when I make the ambient higher then 1 of an object to starts
> to loose it's color i.e. it gets white.
All the components must be in range 0-1 for display. If one of the
components is already 1 and the ambient gain higher than 1 it gets
clipped for display and this changes the color towards white.
Internally the colors are floats so the color of the emitted light
is still correct.
_____________
Kari Kivisalo
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
> All the components must be in range 0-1 for display. If one of the
> components is already 1 and the ambient gain higher than 1 it gets
> clipped for display and this changes the color towards white.
> Internally the colors are floats so the color of the emitted light
> is still correct.
It doesn't seem to do that. If I turn the up ambient value above 1 the
surroundings get whiter as well if I use radiosity.
Thomas.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
"Kari Kivisalo" <ray### [at] engineercom> wrote in message
news:3BCD8123.471F482B@engineer.com...
>
> All the components must be in range 0-1 for display. If one of the
> components is already 1 and the ambient gain higher than 1 it gets
> clipped for display and this changes the color towards white.
> Internally the colors are floats so the color of the emitted light
> is still correct.
So, one should divide the pigment by the ambient value used? (Hmm, I suppose
it's unrealistic to expect to be able to blind anyone who looks directly at a
rendered image?)
With the following code, how do I get my glowing ball (!) to illuminate the
surrounding sphere? Whatever I set brightness or ambient to, it remains dark,
although the plane is lit...
#version 3.5;
#include "colors.inc"
global_settings {
assumed_gamma 1.0
radiosity {brightness 10}
}
camera {
location <0.0, 0, -4.0>
look_at <0.0, 0.0, 0.0>
}
sphere{0, 50 inverse pigment{White} finish{ambient 0}}
plane{y, -1 pigment{White} finish{ambient 0}}
#declare myAmbient = 1
sphere {
0.0, 1
pigment {Red/myAmbient}
finish{ambient myAmbient}
}
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Thomas wrote:
>
> It doesn't seem to do that. If I turn the up ambient value above 1 the
> surroundings get whiter as well if I use radiosity.
The same clipping is applied also to the surroundings. If you need
to know the correct unclipped color value at some point scale all
ambient and light sources by some value that prevents the clipping,
output linear samples (omit assumed_gamma), look up the pixel value
and divide it by the scale value. Now you have the unclipped color.
It's the limitation of the digital image formats and display
devices used. Povray works correctly internally.
_____________
Kari Kivisalo
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Tom Melly wrote:
>
> So, one should divide the pigment by the ambient value used?
No. Use realistic color values. Povray does the clipping automatically.
It affects only display. It's the same thing what happens with printed
images. The image cannot be brighter than the paper it's printed on.
> With the following code, how do I get my glowing ball (!) to illuminate the
> surrounding sphere?
The problem here is that the source is small when seen from
the outer surface and all the rad sample rays miss it. Ambient
sources require higher count and recursion_limit than light
sources and are thus slower.
I also reduced the radius to make the source more "visible"
to the rad sampling.
#version 3.5;
#include "colors.inc"
global_settings{
assumed_gamma 1.0
radiosity{
pretrace_start 0.04
pretrace_end 0.01
count 500
recursion_limit 1
nearest_count 10
error_bound 0.5
}
}
camera {
location <0.0, 0, -4.0>
look_at <0.0, 0.0, 0.0>
}
sphere{0, 20 pigment{White} finish{diffuse 0.6 ambient 0}}
plane{y, -1 pigment{White} finish{diffuse 0.6 ambient 0}}
#declare myAmbient = 100;
sphere {
0.0, 1
pigment {Red}
finish{diffuse 0 ambient myAmbient}
}
_____________
Kari Kivisalo
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
"Kari Kivisalo" <ray### [at] engineercom> wrote in message
news:3BCDA220.923FCD33@engineer.com...
<snip>
Many thanks, Light-Master...
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Well I'm gonna give this a try and we'll see what the result will be. Thanks
anyway for the advice.
Thomas
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
