TITLE: Mystery Lights
NAME: Ron Gow
COUNTRY: USA
EMAIL: rgow@lanset.com
TOPIC: Mystery
COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT.
JPGFILE: lites_rg.jpg
ZIPFILE: lites_rg.zip
RENDERER USED: 

    PovRay 3.5


TOOLS USED: 

    Terragen, Bryce 5
    Gilles Tran's Makegrass macro
    TomTreeM macro by Tom Aust & Gena Obukhov
    Paintshop Pro 7 used for conversion to .jpg


RENDER TIME: 

    PovRay: 1 hr 55 min 


HARDWARE USED: 

    Pentium IV 1.8gz
    512 mg RAM


IMAGE DESCRIPTION: 

    Earth lights in an ancient stone circle.

    Earth Lights, also known as ghost lights and spook lights, have 
    been seen in locations all around the world. A few of the more 
    famous include the Min-Min lights in Queensland Australia, the 
    Bodhisattva lights in Wutai, China, the Maco Station lights in 
    North Carolina, USA, and the Hessdalen Valley lights in Norway.

    While this eerie phenomenon has mystified people for centuries, 
    with some viewers swearing the lights acted as if intelligent,
    probably no sites are as mysterious as the sightings in the old
    stone circles at Avebury, England, or the Castlerigg circle in
    Cumbria, England.  In 1919 the following description was given 
    of the lights at Castlerigg by a T. Sington:

       "We saw a number of lights in the direction of the 
       druidical circle. Whilst we watched, one of the lights 
       came straight to the spot we were standing. At first 
       very faint as it was approaching, the light increased 
       in intensity. When it came close it slowed down, 
       stopped, quivered and slowly went out."

    The only extensive scientific studies of the phenomenon are 
    still being conducted at Hessdalen, where the lights have been 
    recorded with film and radar. One possible clue to the origin is
    in the fact that the majority of sightings are near geological 
    faults. Another theory is they are some type of piezoelectric 
    effect of stone and earth. 

    Both Avebury and Castlerigg lie along geological faults, and 
    they certainly have lots of stone! Is either or both the answer
    to the Castlerigg circle lights?  Or is it some mystic secret of
    the ancient druids?

    It's a mystery!
    


DESCRIPTION OF HOW THIS IMAGE WAS CREATED: 

    
    Stones were originally created in Bryce's terrain editor and
    rendered as an altitude mask render, which I then used as a 
    height_field in POV.

    Earth lights are spheres containing scattering and emitting 
    media and a bright light, then light_grouped with no global
    lights with softer lights for actual illumination. 

    The only other light in the scene is the sun, a point light. 
    
    Background hills from Bryce also, with trees done with the
    TomtreeM macro applied with the trace() macro.

    Grass done with Gilles Tran's Makegrass macro, and applied to 
    another Bryce height_field using the trace() macro.  (Guess
    what my Learn_New_Macro_Every_Round macro this round was...)

    Sky_sphere is a Terragen render, aided by some POV fog set to
    the same color as the dark clouds in the sky_sphere. A lot of
    thanks to Gilles Tran, Tom Melly and the others at the PovRay 
    newsgroups for help with the fog & media.

    Textures are all procedural by me.

    Started a render with radiosity, but it was turning into a 
    100+ hour render so I aborted it.  I wanted to try again with
    lower settings but didn't have time.
    
    Zip file contains everything except the grass & tree files,
    although I reduced the size of the bitmaps & converted them
    to .jpg to save space. 

    Thanks to the voters in the last round for all the excellent 
    comments, and good luck to everyone in this round.

