TITLE: Heel Print
NAME: Tim Glover
COUNTRY: USA
EMAIL: tglover@nettally.com
WEBPAGE: None
TOPIC: Landmark
COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT.
JPGFILE: antfoil.jpg
ZIPFILE: antfoil.zip
RENDERER USED: 
    PovRay 3.0

TOOLS USED: 
    Moray 3.0, Terrain Maker 1.0, Paintshop Pro 3.11

RENDER TIME: 
    43 hours, 1 min, 28 sec (1 min, 20 sec.parse time)

HARDWARE USED: 
    Dell 233 mHz PentiumII, 64 Mbytes RAM, Win 95

IMAGE DESCRIPTION: 


Ants use scent trails to find their way around.  The foil candy wrapper 
had first been a treasure trove until the last of the sweet chocolate 
residue had been mined out by this ant and her thousands of sisters.  
Then the rich aroma still emanating from the shiny ball became a beacon 
and waypoint on further foraging expeditions -- an olfactory landmark.

Then came the Great Thunder.  Darkness came swiftly as the heavens themselves
crashed to the ground while the entire world shook.  When lightness again came,
the magnificent foil ball was no more.  Now there was a deep depression marking

the land and a shiny, sweet smelling spot where the ball had been. 

The ant's landmark has become only a spot in a greater mark on the land.

(Viewing note:

Please adjust gamma/brightness on your monitor until the dark angular objects
in
mid-screen resemble the beer-bottle glass shards they try to represent. <grin>
And remember, I'm American, so beer bottle glass to me is dark
brown -- nearly opaque.) 


DESCRIPTION OF HOW THIS IMAGE WAS CREATED: 


This entry I vowed to myself to expand my skill set and NOT use any
triangle-meshes.
On my list to learn were Bezier patches, height fields, and CSG,  Just little
trivial things <grin>.

My inspiration came from several sources -- the ant resembles one in a recent
National Geographic article (as do the brown, chewed spots on the grass
leaves).
The foil was donated by my 4-year-old son -- he's a Reese's Peanut butter cup
fanatic.  The original idea (landmark = mark IN the land) and the additional
meaning of an olfactory landmark for an ant came from a comment on the irtc
news server early in the competition.   

The first step was modeling the ant -- she's a series of cylindrical bezier
patches for body segments, spheres for eyes, cylinders for leg segments, and
other cylindrical patches for antenna, mandibles, and proboscis.

Next came the "ground".  I knew I wanted to learn to use height fields, so I
began playing around with random terrains in terrainmaker (TM).  Due to my own
failings, I couldn't figure out how to bring in my hand-created heel mark --
done
in Paint Shop Pro (PSP) -- so I exported the terrain from TM to PSP and added
the
heel mark (learned a few tricks in PSP doing this, too).  Then I added the
ground
and found I had a hovering ant -- and worker ants don't even have wings!  After
some
trial and error fittings, I had the ant poised at the edge of the heel-mark pit.
 

Next came the grass.  Wow.  I started off with a simple leaf from my Coastal
Bahia
lawn.  Seemed pretty simple -- mostly a rectangle with a smooth taper at the
end. 
Then I noticed the curve droop of a grass leaf -- my first one looked like a
Cattail
plant.  Added a droop. Then I realized I'd need about 10000 such leaves to make
it
look realistic.  Stopped working on the entry for several days in disgust
<grin>.

Then I read up on instancing.  Hmmm... Possible salvation.  I made two
different
grass sprigs and cloned them unmercifully, hand-placing them and tweaking scale
and rotations so they don't look cloned.  Then I started on the grass texture.
Since I had a piece of grass in my hand, I figured it would take 10-20 minutes
to
get right.  That was July 14.

The first texture took about 3 hours -- I'd not used color gradients and bump
maps before -- and looked too perfect.  Every rib was pristine.  Every blade
was
perfect.  Time to read up on CSG to add a few holes.  

A few months ago I saw a really nice rendering of a fossil with random dirt
specks
on a desk top.  (With the author's permission, I've used it as a wallpaper on
my
machine at work).  He'd used a height field to create the dirt and I figured I
could do something similar to add a few random chew holes to the grass.  So I
made
up a height field with some random noise spots and differenced them with the
grass
tufts.  After switching the order so the grass appeared with holes, instead of
the
holes floating in mid air and no grass -- order IS important -- it looked
pretty
cool.  But it still looked too clean.  Finally, I scanned through my trusty
Nat.
Geo. library and found a close-up of some leaves -- the bug holes weren't clean
holes!  They were ragged, and many of the veins of the leaf were still left --
I guess they're too tough to chew.  SO, after playing around for about a month,
I finally hit upon the technique you see here -- a CSG difference between the
grass
and the hole-field to make random holes, then an intersection of another grass
and
a duplicate of the hole-field to add the lacy brown gnawed portions -- two
separate
CSGs on big unions and height fields. WOW.
      
Then I realized I'd need several more ground height fields, since my grass was
falling off the back -- after puzzling for an hour or so, I figured out how to
mirror and flip the original ground height field (before the addition of the
heel mark) so edges matched without showing seams.

Next came the foil.  After so much "experience" with height fields, I whipped
through the creation of the actual foil pretty quickly -- scan real crumpled
foil, tweak the intensities until the texture looks crinkled as a height field,
then add an appropriate texture and pigment.             

Finally, I added several window dressing props, the pebble(s) -- there's really
only one, it's also a bezier cylinder that's then instanced, scaled, and
rotated
randomly -- and the beer bottle glass shards -- simple linear extrusions --,
just
to add to the general squalor of the place.  By the way, the beer bottle glass
texture was amazingly difficult -- it has almost no transmittance.

So, yeah, just a little something I threw together after scarfing someone's
idea <grin>.

