Following all this radiosity talk, I have made a minor discovery. I think
Alain hinted that this was possible in a radiosity-related post last month,
so it's probably not totally new, but it seems that when using radiosity
lighting with transparency you get caustics naturally without any need for
photon-mapping!

Did anyone else know this?

#include "colors.inc"
global_settings {
  assumed_gamma 1
  max_trace_level 10
  radiosity {
    pretrace_start 0.08
    pretrace_end 0.01
    count 750
    nearest_count 2
    error_bound 0.1
    recursion_limit 12
    low_error_factor 0.5
    gray_threshold 0
    minimum_reuse 0.0001
    brightness 1
    adc_bailout 0.01/2 } }
camera {
  location <0, 5, -5>
  angle 45
  look_at <0, 0, 0> }

sphere { <10, 10, -10>, 3 pigment { color rgb 18 } finish { ambient 1 } }

difference {
  sphere { <0, 0, 0>, 1.5 }
  sphere { <0, 0, 0>, 1.4 }
  pigment { color Clear }
  finish { ambient 0 }
  interior { ior 1.5 } }
sphere {
  <0, 0.3, 0>, 0.3
  pigment { color Clear }
  finish { ambient 0 }
  interior { ior 1.5 } }
plane {
  <0, 1, 0>, 0
  pigment { color White }
  finish { ambient 0 } }

Good, eh?

Post a reply to this message

Attachments:
Download 'radtest.jpg' (47 KB)

Preview of image 'radtest.jpg'

"Bill Pragnell" <bil### [at] hotmailcom> wrote in message
news:web.45ed80479077db1f731f01d10@news.povray.org...
> Following all this radiosity talk, I have made a minor discovery. I think
> Alain hinted that this was possible in a radiosity-related post last month,
> so it's probably not totally new, but it seems that when using radiosity
> lighting with transparency you get caustics naturally without any need for
> photon-mapping!

tried it long ago (see
http://www.povplace.com/gallery/Old%20-%20Test-scenes/thumbs/41.jpg ) but I also
discovered then that 1600 samples was as high as you could go, which clearly is
too low for accurate caustics.

cu!
--
#macro G(b,e)b+(e-b)*C/50#end#macro _(b,e,k,l)#local C=0;#while(C<50)
sphere{G(b,e)+3*z.1pigment{rgb G(k,l)}finish{ambient 1}}#local C=C+1;
#end#end _(y-x,y,x,x+y)_(y,-x-y,x+y,y)_(-x-y,-y,y,y+z)_(-y,y,y+z,x+y)
_(0x+y.5+y/2x)_(0x-y.5+y/2x)            // ZK http://www.povplace.com

Post a reply to this message

"Zeger Knaepen" <zeg### [at] MOVEpovplacecom> wrote in message
news:45ed9b6c$1@news.povray.org...
> "Bill Pragnell" <bil### [at] hotmailcom> wrote in message
> news:web.45ed80479077db1f731f01d10@news.povray.org...
> > Following all this radiosity talk, I have made a minor discovery. I think
> > Alain hinted that this was possible in a radiosity-related post last month,
> > so it's probably not totally new, but it seems that when using radiosity
> > lighting with transparency you get caustics naturally without any need for
> > photon-mapping!
>
> tried it long ago (see
> http://www.povplace.com/gallery/Old%20-%20Test-scenes/thumbs/41.jpg )

I mean http://www.povplace.com/gallery/Old%20-%20Test-scenes/41.jpg of course

cu!
--
#macro G(b,e)b+(e-b)*C/50#end#macro _(b,e,k,l)#local C=0;#while(C<50)
sphere{G(b,e)+3*z.1pigment{rgb G(k,l)}finish{ambient 1}}#local C=C+1;
#end#end _(y-x,y,x,x+y)_(y,-x-y,x+y,y)_(-x-y,-y,y,y+z)_(-y,y,y+z,x+y)
_(0x+y.5+y/2x)_(0x-y.5+y/2x)            // ZK http://www.povplace.com

Post a reply to this message

Bill Pragnell wrote:
> Following all this radiosity talk, I have made a minor discovery. I think
> Alain hinted that this was possible in a radiosity-related post last month,
> so it's probably not totally new, but it seems that when using radiosity
> lighting with transparency you get caustics naturally without any need for
> photon-mapping!
> 
> Did anyone else know this?

Yes, I remember when it was added as a feature. It was touted as 
"radiosity through transparent surfaces" or something. It's too bad it 
takes so long to render :/ It would be a cool way to make lens refract a 
window's image onto a wall.

~Sam

Post a reply to this message

I noticed that in the hdri scene included with Pov-ray.


-- 
-Nekar Xenos
"The truth is out there"

--------------------------------------------------------------------------------
I am using the free version of SPAMfighter for private users.
It has removed 460 spam emails to date.
Paying users do not have this message in their emails.
Try SPAMfighter for free now!

Post a reply to this message

Bill Pragnell wrote:
> it seems that when using radiosity
> lighting with transparency you get caustics naturally without any need for
> photon-mapping!

  A really slow way of getting caustics... :P

Post a reply to this message