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Re: Caustics on a surface under an object - Tim Niklas
From:
Stefan Viljoen <rylan@<deletehis>
Reply-To:
rylan@<deletethis>intekom.co.za
Date:
Sunday 23 May 2004 20:45:16
Groups:
povray.binaries.images
no references
Tim Nikias v2.0 wrote:
>> If I want caustics on a surface BELOW a photon target, must the surface
> that
>> the photon target is on also be a photon target?
>>
>> I have tried many combinations but simply cannot get caustics on a
>> surface "behind" a photon target, even with very small spacings and lots
>> of
> photons
>> - all my photon caustics stay confined to the glass object. I simply
> cannot
>> get caustics onto the table "behind" the glass standing on it.
>
> Can you provide small, minimal sample scene (post it on
> povray.binaries.scene-files), so that I could have a look at it? You could
> also try to put both objects in a union and shoot photons at the union,
> but that's just a random guess, nothing based on experience or such.
>
Hi Tim!
Thanks for replying to my post - I think I have at least demystified it for
myself a bit. I made the following test scene:
global_settings
{
adc_bailout 0.05
max_trace_level 10
photons
{
spacing 0.01
jitter 0.15
max_trace_level 10
adc_bailout 0.05
autostop 0
radius ,1.75
//save_file "phottest.pht"
}
}
camera
{
location <0,0,5>
look_at <0,2,0>
}
light_source
{
<4,4,5>
color rgb <1,1,1>*2
photons
{
refraction on
reflection on
}
}
box
{
<-1,-1,-1>
<1,1,1>
material
{
texture
{
pigment
{
color rgb <1,0,0>
}
}
}
scale <2,2,1>
}
cylinder
{
<-1,-1,-1>,
<-1,1,2>
0.25
material
{
texture
{
pigment
{
color rgbft <0,0,1,0.3,0.65>
}
finish
{
diffuse 0.55
ambient 0.45
specular 0.9
roughness 0.2
metallic 0.25
reflection 0.25
}
}
interior
{
ior 1.3
dispersion 1.4
dispersion_samples 10
caustics 2
}
}
translate <1,0,0>
photons
{
target 0.75
reflection on
refraction on
}
}
This works ok. However in my scene I am working on (a bit too big to post),
specifying the object like this (I copied exactly the same ior, texture,
and shape) makes it turn absolutely 255,255,255 white - I have one very
distant (1000 units away) light. Specifying "collect off" in the glass
object's statement makes its texture be okay, but I guess THIS is why it
does not leave caustics on the surface it is standing on.
Any idea how I can prevent the photon object being "white out"-ed when I
remove "collect off"? Obviously I am making some mistake and specifying
"collect off" makes the class NOT leave caustics like I want it to.
Thanks!
Stefan Viljoen
Software Support Technician
Polar Design Solutions
--
Stefan Viljoen
Software Support Technician
Polar Design Solutions
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