TITLE: Stone of Stennis
NAME: Gary MacKinnon
COUNTRY: USA
EMAIL: gary@mackinnon.com
TOPIC: Lonliness
COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT.
JPGFILE: jgmrock.jpg
ZIPFILE: jgmrock.zip
RENDERER USED: 
    Pov-ray 3.5

TOOLS USED: 
    Paint Shop Pro to convert to jpg.

RENDER TIME: 
    1 hour

HARDWARE USED: 
    Athlon 1700 with 1GByte Ram

IMAGE DESCRIPTION: 

Almost 3000 years ago in Scotland a Neolithic civilization erected stone
monuments. This one is part of the Stones of Stennis which is on the isle of
Orkney.  The image was inspired by a photograph in a book titled "Minimum" by
John Pawson. 

The image is simple but its very simplicity makes it difficult.  The eye is
drawn to the individual details of shape and color far more so than in busy
scenes where the three dimensionality of the composition provides much of the
eye appeal.  The rock is the central focus of attention and natural rock shapes
are very difficult to model mathematically. The rock had been carved by humans
into a basic prismatic shape but weathering over the years has roughened the
surfaces.  



DESCRIPTION OF HOW THIS IMAGE WAS CREATED: 

The image source is all Povray script.

The rock was modeled using Povray's isosurface primitive. Basically it is a set
of intersecting planes modified by noise.  The source code for the rock is
included.

The clouds are created using pigments on a couple of planes.  The dark storm
cloud was a circle with some noise thrown in to fray the edges.  This cloud is
not of uniform color.  Two shades of dark gray were combined with noise to give
the cloud a more realistic appearance.  A higher plane of whiter clouds was
also created to place clouds at the horizon.  Also a slightly gray ground fog
was added to give a more realistic appearance to the horizon.

The area that was most challenging was the grass field. I started with a macro
to create grass written by Gilles Tran but this was really more suited for a
closeup of grass blades.  When applied to a large field it was all of uniform
color and height so I added several features.  First the grass was allowed to
be placed on top of a variable surface. Second, I allowed the color of
individual grass blades to vary. Next, the distribution of grass height was
made far more scewed so that there are few very long blades but lots of short
ones.  Finally, I created a mechanism where blade colors not only varied
locally but varied also on a larger scale so that the color of the field was
not uniform as one looked across it.



