Someone requested an update on the photon mapping patch.  Here's a pic.  :)

Here we see three lenses lit by three light sources.  The middle lens
has photon mapping turned off (the default), so it casts normal filtered
shadows just like any other object.  If you look on the blue box, you'll
see light reflected from the bronze box.  There's also some light reflected
from the bronze box that goes through the lens nearest to the camera.

Image stats:
size: 320x240
aa: 0.3
render time: 3:25
number of photons: 67,968
peak memory used: 3,004,062

-Nathan

Post a reply to this message

Attachments:
Download 'test1b.jpg' (21 KB)

Preview of image 'test1b.jpg'

*YUMMA*

GReat job on both... *drool*

-- 
//Spider 
( spi### [at] bahnhofse ) [ http://www.bahnhof.se/~spider/ ]
#declare life = rand(seed(42))*sqrt(-1);

Post a reply to this message

This is stunning!!!!!

hurry up and get it released!!!!!!

Rick

Nathan Kopp wrote in message <36D8E0E2.36503AC2@Kopp.com>...
>Someone requested an update on the photon mapping patch.  Here's a pic.  :)
>
>Here we see three lenses lit by three light sources.  The middle lens
>has photon mapping turned off (the default), so it casts normal filtered
>shadows just like any other object.  If you look on the blue box, you'll
>see light reflected from the bronze box.  There's also some light reflected
>from the bronze box that goes through the lens nearest to the camera.
>
>Image stats:
>size: 320x240
>aa: 0.3
>render time: 3:25
>number of photons: 67,968
>peak memory used: 3,004,062
>
>-Nathan

Post a reply to this message

I will not pressure you... I will not pressure you... I will not pressure
you... I will not pr...
Please, hurry up and release it! (sorry ;)

>There's also some light reflected from the bronze box
>that goes through the lens nearest to the camera.

Am I to understand you can also do caustics from secondary light sources
(caustics from caustics)?!

Margus

Post a reply to this message

Nathan Kopp wrote:
> 
> Someone requested an update on the photon mapping patch.  Here's a pic.  :)
> 
> Here we see three lenses lit by three light sources.  The middle lens
> has photon mapping turned off (the default), so it casts normal filtered
> shadows just like any other object.  If you look on the blue box, you'll
> see light reflected from the bronze box.  There's also some light reflected
> from the bronze box that goes through the lens nearest to the camera.

Looks like it might be a useful feature maybe.

-- 
Ken Tyler

mailto://tylereng@pacbell.net

Post a reply to this message

Nathan Kopp wrote in message <36D8E0E2.36503AC2@Kopp.com>...
>Someone requested an update on the photon mapping patch.  Here's a pic.  :)

The images are great, especially considering the small # of photons used.

A couple of questions:

1) Did you ever solve the problem with splotchiness when firing random
photons? If you're still using a scanning approach do you handle the case
where an object surrounds a photon source? You'd need to scan based on
spherical coordinates in that case.

2) Are you using wavelength dependent ior or are the r,g,b caustics due to
different positions of the lights? If you're doing wl-dependent ior, how do
you encode the light's spectrum in the photon? I punted and simply fired
multiple single-wavelength photons (jittered spectrum sampling) if the
target had a wl-dependent ior (and prayed that subsequent objects weren't
wl-dependent).

Thanks
Mike

Post a reply to this message

ivfer wrote:
> 
> 1) Did you ever solve the problem with splotchiness when firing random
> photons? If you're still using a scanning approach do you handle the case
> where an object surrounds a photon source? You'd need to scan based on
> spherical coordinates in that case.

No.  I use a jittered uniform scan.  And I always use spherical coordinates.
That way it provides even distribution of photons on the surface of a
sphere centered on the origin, which is more physically accurate (as
opposed to evenly distributed on a planar surface).

> 2) Are you using wavelength dependent ior or are the r,g,b caustics due to
> different positions of the lights? If you're doing wl-dependent ior, how do
> you encode the light's spectrum in the photon? I punted and simply fired
> multiple single-wavelength photons (jittered spectrum sampling) if the
> target had a wl-dependent ior (and prayed that subsequent objects weren't
> wl-dependent).

The rgb caustics come from three lights in different positions.  This does
do wavelength dependent ior, too (images attached).  Instead of sampling
the spectrum randomly, I allow the user to give a list of wavelengths
(in the form of RGB vectors) that make up the light.  I use a modified
version of Daren Wilson's dispersion patch, along with your rgb->hue
conversion function to do the rest.

-Nathan

Post a reply to this message

Attachments:
Download 'prism.jpg' (16 KB) Download 'prism2.jpg' (8 KB)

Preview of image 'prism.jpg'

Preview of image 'prism2.jpg'

Nathan Kopp wrote:

>  [Image]  [Image]

This discussion is way over my head, but this looks like a neat patch.
I see a remake of a certain famous Pink Floyd album cover in the future!
LOL!

Post a reply to this message

It's amazing alright. How'd you manage the light reflection? I didn't
know this was part of it. The parallel rays/parabolic mirror thing is
possible then huh? And again that render time is extra-ordinary. I'll
pay no attention to the memory used.


Nathan Kopp wrote:
> 
> Someone requested an update on the photon mapping patch.  Here's a pic.  :)
> 
> Here we see three lenses lit by three light sources.  The middle lens
> has photon mapping turned off (the default), so it casts normal filtered
> shadows just like any other object.  If you look on the blue box, you'll
> see light reflected from the bronze box.  There's also some light reflected
> from the bronze box that goes through the lens nearest to the camera.
> 
> Image stats:
> size: 320x240
> aa: 0.3
> render time: 3:25
> number of photons: 67,968
> peak memory used: 3,004,062
> 
> -Nathan
> 
>   ------------------------------------------------------------------------
>  [Image]

-- 
 omniVERSE: beyond the universe
  http://members.aol.com/inversez/POVring.htm
 mailto:inv### [at] aolcom?PoV

Post a reply to this message

I didn't think you'd be able to do something like THAT.  45 seconds? 
Wow!

-Mike

 
> The rgb caustics come from three lights in different positions.  This does
> do wavelength dependent ior, too (images attached).  Instead of sampling
> the spectrum randomly, I allow the user to give a list of wavelengths
> (in the form of RGB vectors) that make up the light.  I use a modified
> version of Daren Wilson's dispersion patch, along with your rgb->hue
> conversion function to do the rest.
> 
> -Nathan
> 
>   ------------------------------------------------------------------------
>  [Image]  [Image]

Post a reply to this message