TITLE: Chromatic Scale
NAME: Aaron Gage
COUNTRY: USA
EMAIL: agage@mines.edu
WEBPAGE: http://www.mines.edu/students/a/agage
TOPIC: Art and Entertainment
COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT.
JPGFILE: amgchrom.jpg
ZIPFILE: amgchrom.zip
RENDERER USED: 
    POVray 3.0 for Linux

TOOLS USED: 
    None

RENDER TIME: 
    23 02 58 on a borrowed Pentium 200Mhz MMX

HARDWARE USED: 
    i486DX2/66 with 20 Megs RAM under Linux 2.0.28

IMAGE DESCRIPTION: 


        There are two definitions of "chromatic": of or relating to color,
and the progression by half steps of the musical scale.  Since the topic
was Art and Entertainment, and to me, the piano is both of these, I thought
I'd try to bring out both definitions of the chromatic scale in my image.

        This piano is a bit different than most -- it could be a grand
piano, except for the fact that the strings are held vertically by a pair
of arches.  Around each string is its unique color, determined by the note
and the octave.

        The painting on the wall to the left of the strings is a work
of Maxfield Parrish (1870-1962) entitled "The Young King of the Black Isles",
which was created in 1906.  More information about this work is at the
end of the next section.  Based on the nature, age, and availability of
this particular work, I am making the assumption that it is in the public
domain; that is, that I am not in violation of copyright by using this
image.  U.S. Code, Title 17 - Copyrights states that the term of copyright
for visual art shall consist of the life of the author.  This work is also
available in various forms, including postcards, calendars, and unregulated
electronic media.  If, despite this evidence, the use of this painting in
my scene is viewed as inappropriate or in violation of copyright, I will
retract the image and withdraw it from the competition.


DESCRIPTION OF HOW THIS IMAGE WAS CREATED: 


        I have always been a purist when it comes to modelling, so the entire
scene was modelled by hand (though I did use a pen and paper to sketch a few of
objects).

        The keyboard was made as a union of 88 keys, each of which were made
out of superellipsoids with a little CSG.  The piano case was actually very
easy to make, using boxes and CSG to define the shape and cut my last name in
gold letters above the keys.

        The string assembly, or harp as I have been calling it, was a little
tricky, and I still can't get it to be as smooth as I'd like.  The shape is
a cosine wave for the first half-period.  The object was created using a
union of 176 (88*2) cylinders, each of which has its endpoints on the curve
at either side of a given point.  This produces the shape nicely, but some
banding still appears on the arch, depending on the light.  If I could have
figured out how to do this as an intersection, I would have -- but
intersections do not seem to work as well in #while loops.  The arches on
either side are cylindrical superellipsoids, with cylinders subtracted from
them.

        The strings are very, very thin silver cylinders.  They are each
surrounded by a thin halo, which has its color and turbulence assigned by
an include file that is called for each string.  I had originally intended
to have 2-3 strings per key, but as it was, I had to use a very low threshold
of antialiasing just to be able to distinguish them with one per note.  My
original conception of the scene included a wispy trail of color reaching
from each of the sounding strings into a ethereal scene -- essentially, to
give form, shape, and color to the chord being played, so that the music
could be seen.  Unfortunately, the filtering that took place by superimposing
halos on each other to produce this effect caused a few artifacts, so I
had to abandon the idea.

        The room is just the intersection of a few planes with a box that
defines the size -- I used discrete planes so I could give each wall a
different color, but I ultimately didn't need this freedom.  The window is
simply a subtraction from one of the planes, with a wooden frame and a thin
layer of glass.  I'm very pleased with the wall panelling, since each
"board" is just a box with three CSG subtractions.  The marble table is
also just simple CSG, modelled after something I've seen, but with a couple
of gold rings for decoration.  The piano bench is nothing special -- most of
it can't be seen from the final view -- just more boxes in CSG.

        The painting hanging on the back wall is a work by the late
Maxfield Parrish called "The Young King of the Black Isles".  I had seen
this painting before, and it had caught my attention because it was also
the inspiration for the cover of Enya's "The Memory of Trees".  Once I
realized that my idea for showing musical notes spinning into visual form
was not going to work, I had some white space on the wall to use up.  I
couldn't think of anything particularly appropriate to put there; I didn't
have the time to design a candle holder, and a mirror might show that my
room has no door.  It seemed only natural that a painting might be found
on a study wall, so I went after this obscure yet very beautiful painting.
I found that most of Maxfield Parrish's paintings were equally amazing --
and I encourage anyone with a little free time to look him up on the Web.

        If I had had more time, I would have made the area outside of the
window more interesting.  The height field that created the hills is textured
using a bozo color map, though a tree or lake or something might have made it
more interesting.  The light across the hills is from a different direction
than that lighting the room, so some shadows might appear in seemingly odd
places.

        As it was, I had to render the image on another machine, as on
my DX2/66 it would have taken about 26 days.

        Incidentally, although I abandoned the effect of giving form to
a musical melody, I left a particular chord set up on the piano.
The chord being played is actually a fairly pleasant one -- I doubt I have
the key signature correct, but here are the keys:

           D# A# D# G A#    <mid C>   G A# F   + D# + D

        The middle C key is not played, I just dropped that there for
reference.  A ten note chord is a bit much to be played at once, I know --
the highest three notes sound in succession, descending, as the lower
five notes progress up.  I'll send full image source to the first person
who guesses what piece I got the chord from :)

