TITLE: "Jewel Box of the Giants"
NAME: Matt Giwer (Matthias M. Giwer)
COUNTRY: USA
EMAIL: jull43@ij.net, jull43@aol.com
WEBPAGE: http://members.aol.com/jull43
TOPIC: Imaginary Worlds
COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT.
JPGFILE: giants5.jpg
ZIPFILE: giants5.zip
RENDERER USED: 
    POV-Ray

TOOLS USED: 
    POV-Ray, Photoshop

RENDER TIME: 
    9 hours and change or 2hr50m see below

HARDWARE USED: 
    Pentium II, 333MHz, 128MB RAM

IMAGE DESCRIPTION: 
    Inside the jewelry box of a Giant


DESCRIPTION OF HOW THIS IMAGE WAS CREATED: 
    Many moons ago I tried
lapidary as a hobby. That is expensive enough but the "perfect" 
rough to cut was even more expensive. Scratch one hobby. As a 
POV-Ray learner since December 1998* I found the perfect learning 
tool, gemstones. Perfect gemstones only cost time instead of 
dollars. 

    And I came across the theme of imaginary worlds. And here I 
had pearls and cut stones and lots of experience in multiple 
reflections and then it was only fitting what I had available 
into the theme. Giant gemstones to Land of the Giants was an easy 
leap. And the TV show Land of the Giants was created in Hollywood 
which is another imaginary World so I was in two ways from 
Sunday. 

    The colored diamonds are only an approximation of the right 
shape and are short a row of facets on the crown (the side with 
the flat spot called the table.) Other than that, they are quite 
busy enough for this image. Too many facets have a poor result in 
reality not to mention here. 

    BTW: Do not object to colored diamonds. The Hope Diamond is 
as least as deep a blue as rendered here. And anyone objecting to 
the external face reflections, you have not looked at a faceted 
stone under a ten power loupe. This is a reasonable rendering. 
And most of the visual value of gemstones comes from moving them 
which is contrary to rendering save as an animation. 

    From there on it was all hand placement and rotation, 
rendering individual and small groups of items and the occasional 
overnight rendering of the complete scene. I am not really happy 
with the black opal on the right. The colors should be more 
"glinting." But the fine chain for it came out perfectly in the 
rendering. It might be the most realistic thing in the entire 
scene. 

    The "diamonds" are the intersection of superellipsoids of { 
2, 2 } which is roughly a raw diamond crystal in itself. From 
there I rotate and scale to provide the facets. These improve up 
to max_trace_level 12 but of course takes forever to render 
individually, not to mention this complex scene. 6 is used for 
this scene. The colors were added for visual interest and the 
"emeralds" given their traditional 1:5/8 oval shape by simple 
scaling. 

    The sheen from the pearls comes from twenty (overkill as 
there are not enough trace levels to get down to it) transparent 
concentric spheres each with the same texture with a solid sphere 
in the center. The solid sphere gets right a a tendency of the 
software to "fake" a caustic getting through even though no light 
could get through before ADC bailed out. 

    The concentric spheres are an attempt to imitate nature as 
pearls are composed of such thin layers. They improve up to 
max_trace_level 20 but if there are other reflecting objects in 
the scene, the stack overflows. But if you increase the trace 
level you have to decrease the transmission as the "opalescent" 
effect increases with the number of internal reflections 
permitted. 

    The "best" pearls pick of the tones of the person wearing 
them. This does so in spades. Perhaps too much for normal usage. 

    The wood has no color of its own. It simply reflects only 
reds. It is an effect I like as it can exist but not add its 
color to the scene save as a function of other lights. 

        In order to obtain the viewing perspective 

#declare place = 1*<3,2.75,4> 
camera
{
  location place 
  direction 1.25*z // slightly fisheye 
  right 4/3*x
  look_at <0.0, 2.5, 0.0> // looking slightly down from the 2.75 high location
through the 2.5 
}

        This lets the eye look "up" and "down" at the scene. 

    I am particularly happy with the way the detail on the 
"tubular" beads of the larger hanging ring came out. This was one 
of the happy accidents. It was an attempt at the smaller object 
in front of it with too many spheres specified. So they 
overlapped and gave interesting gold beads. Never throw away an 
interesting effect. 

    Lighting is done by putting the entire scene and the lights 
inside a proportional "room" of six planes that intersect. 
Nothing special is done with them but they provide an ambient 
light in a realistic manner. What you see in the top center of 
the image is the intersection of a wall and the ceiling. The 1 
and the .33 light both also illuminate the interior of the box. 

    Photoshop was used to create the height map for the coin 
face. Adding copyright this way is a more interesting use of 
Photoshop than stripping it in as an afterthought. And besides, I 
get to use my ugly puss this way. 

    And at first I thought my simple render model was terrible 
but then I pulled out my one Krugerrand and it was exactly like 
this. It is a collector not a trade coin so no raised edges nor 
knurled sides. The "texture" on the side of the coin stack is 
from reflections only. 

    In the process of creating jewelry I came up with some quite 
interesting pieces but they had the annoying problem of requiring 
an hour to render a small segment of a 320x240 window. I have to 
put those off until the 3 (or 30) Gigahertz machines are 
invented. So will area lights as the one that comes with to 
insert increases the time by a factor of four although it is a 
much better scene. 

    As to the rendering time, if I reboot the machine and load 
POVRay first, rendering takes just under 3 hours. But if I have 
been running the machine for a while and doing other things it 
will take a bit over 9 hours. I have no idea what is causing this 
difference yet. I have raised the issue on the pov-ray@povlab.org 
mailing list for insight.

---

* If we ignore five years ago with a 486DX2/66 which lasted for 
three frustrating months and didn't get anywhere. 


