Just posting this here as a reference showing the effect of the 2 major values
for the irid {} finish.
turbulence was held at a constant 0.75, but anything between 0.25-1 works well,
and higher values might be useful for other effects.

Again, it's the environment that really lets you see the characteristic bubble
texture.

- BW

Post a reply to this message

Attachments:
Download 'iridescencetests.png' (623 KB)

Preview of image 'iridescencetests.png'

I had the idea to render a similar scene showing the effect of varying the rgb
components of the irid_wavelength global setting.

https://wiki.povray.org/content/Reference:Global_Settings#Irid_Wavelength

Even though "You may have multiple global_settings statements in a scene."

Apparently, "Whatever values were specified in the last global_settings
statement override any previous settings." and this affects all the irid{}
statements, you can't sequentially assign different global settings to objects
in the same scene.

Kinda obvious, but I did it just to check.  Bummer.

I'm voting for irid_wavelength to be moved into the irid {} code of the finish
{} block in future versions.

- BW

Post a reply to this message

"Bald Eagle" <cre### [at] netscapenet> wrote:
> "Robert McGregor" <rob### [at] mcgregorfineartcom> wrote:
>

>
> Droj just posted his version, and with just a black background, it looked ---
> like poop.
>

> - BW

Yes BE, it looks like poop but it wasn't meant to show my artistic capabilities.
It was just a reminder for you that there is a example file for iridescence
coming with Povray.
I simply changed the pigment from white to clear using your data.

So put the blame on the author of the original file for not providing a nice
background.

- Droj

Post a reply to this message

"Droj" <803### [at] drojde> wrote:

> Yes BE, it looks like poop but it wasn't meant to show my artistic capabilities.
> It was just a reminder for you that there is a example file for iridescence
> coming with Povray.
> I simply changed the pigment from white to clear using your data.

Yes, yes, I understand completely, and I knew I was flirting with disaster
trying to explain things.


> So put the blame on the author of the original file for not providing a nice
> background.

No blame was being assigned, the point was that your texture is _beautiful_, but
if the user rendering a scene with it doesn't know the behaviour and limitations
of the irid {} feature, then a plain background will completely destroy it, and
beautiful as the texture might be - the end result is unfortunately....

:(

I beg your humble pardon for any unintended offense.

- B "the ineloquent" E

Post a reply to this message

"Bald Eagle" <cre### [at] netscapenet> wrote:
> "Droj" <803### [at] drojde> wrote:
>
> > Yes BE, it looks like poop but it wasn't meant to show my artistic capabilities.
> > It was just a reminder for you that there is a example file for iridescence
> > coming with Povray.
> > I simply changed the pigment from white to clear using your data.
>
> Yes, yes, I understand completely, and I knew I was flirting with disaster
> trying to explain things.
>
>
> > So put the blame on the author of the original file for not providing a nice
> > background.
>
> No blame was being assigned, the point was that your texture is _beautiful_, but
> if the user rendering a scene with it doesn't know the behaviour and limitations
> of the irid {} feature, then a plain background will completely destroy it, and
> beautiful as the texture might be - the end result is unfortunately....
>
> :(
>
> I beg your humble pardon for any unintended offense.
>
> - B "the ineloquent" E

BE,
Honestly, no offense taken.
And it was not 'my texture' - the original is a Povray 3.7 scene file which I
'misused' in my strong belief to put you on the 'right track' when I saw your
first post. So no time for a neat background with tangerine trees and
marshmellow skies and a couple of fairies flying around.

And I am sure that you know what the coder gurus always used to say : RTFM! :))

Cheers
- Droj

Post a reply to this message