> Hi all,
> 
> I'm new to Povray and have learned most of the basics so far to achieve what I
> want. However I am trying to create an image with some glass objects and can't
> quite get the lighting and vibrancy how I want it.
> 
> This is an image here:- http://www.flickr.com/photos/40381418@N02/3717188064/
> on Flickr. Can anyone show how this image was made, especially the lighting and
> the glass material and how it's so vivid and vibrant please.
> 
> Any help/pointer would be greatly appreciated.
> 
> thanks
> 
> Tizer001
> 
> 
> 
Any glass object need some additional parameters:

  - An interior block that contains an ior
  - That interior block can also include a fade_color, fade_distance and 
fade_power to set the colour of the substance composing the object.
  - To increase realism, add some dispersion. This increase the 
rendering time.

With no ior, light won't bend, resulting in an object looking somewhat 
like a bubble.

Sample interior block:
interior{ior 1.5 // typical class
	dispersion 1.03 // should be kept low and > 1 to be realistic
	fade_dolor rgb<0.7, 0.75, 0.9>// a bluish glass
	fade_distance 10 // relatively small effect. Adjust for the size of 
your object.
	fade_power 1 // or 1001 to use "exponential" fading
}

The finish should include a variable reflection block with the fresnel 
option. Don't forget to add conserve_energy to the finish.

Sample complete finish:
finish{ambient 0 diffuse 0.1 // don't interact much directly with the light
  specular 0.7 roughness 0.0001 // get relatively tight highlights
  reflection{0.1 0.95 fresnel} // prety normal for glass
  conserve_energy}

The highlights realy add a lot. They help give perceptual volume to the 
objects.

To get realistic caustics, you need to add a photons{} block to the 
global_settings AND another photons block to your glass object.

Sample minimal global photons block:
photons{count 1000000}// set how many photons you want to shoot
photons{spacing 0.01} // set the density at whitch you want the photons shot

Glass object typical photons block:
photons{ target // enable shooting photons at this object
  refraction on // turn photons refraction on
  reflection on // turn photons reflection on
  collect off // save time. Photons don't show much on transparent 
objects anyway.
}

Your light_source don't need a photons block. It have the folowing 
DEFAULT one:
photons{refraction on reflection on}

A lone glass object is rather boring. It needs some environment to realy 
show. Even if you don't see them, a sky_sphere or some ther objects can 
help.


Alain

Post a reply to this message