TITLE: Cathedral
NAME: Ron Gow
COUNTRY: USA
EMAIL: rgow@lanset.com
TOPIC: Spectacular Landscapes
COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT.
JPGFILE: cathe_rg
RENDERER USED: 
    Bryce 5

TOOLS USED: 
    Bryce 5, HamaPatch, LSystem5
    Paintshop Pro 7 used for textures and conversion to .jpg

RENDER TIME:  35 hrs 31 min
    

HARDWARE USED: 
    Pentium IV 1.8gz
    512 mg RAM


IMAGE DESCRIPTION: 

"The greatest meeting of land and sea in the world"  was Albert Camus' 
historic description of Point Lobos, California.  But Camus only saw half 
of it.  The spectacular canyons and cliffs that make the Point Lobos headlands 
one of the most painted and photographed landscapes on the Pacific coast do not 
end when they hit the water.  The terrain continues on into the ocean, dropping 
over 3000 ft in less than a quarter mile.

The cold, nutrient rich upwellings from those vast depths combine with 
the warmer currents moving up Baja and Big Sur, to provide fertile
waters for the giant kelp forests which cover the rocky reefs that are 
the tip of Point Lobos. 

On August 28, (while waiting for the new topic), I was fortunate 
enough to dive Point Lobos on one of the rare days when the usual 30-40 ft 
visibility was stretched to 100+.  An incredible dive, we used every breath
of air in our tanks.

This scene is a spot my dive buddies and I nicknamed the Cathedral because 
the light filtering though the kelp reminded us of the stained glass windows. 

Here's from my logbook:  Came northeast up out of the middle reef, entering the 
center channel over a shelf at 46 ft.  Overhead the sun was shining through the 
kelp like a canopy of light.  Hydroids, eel grass, tunicates, coraline algae, 
hydrocorals and sponges covered the surface, with a red anemone, some starfish 
and purple urchins competing for space.  To my right a Salp chain drifted 
slowly, ahead of me, a Bat Ray was leaving his hiding spot in the sand for 
more secluded water and above me a school of black rockfish circled. Beautiful!


DESCRIPTION OF HOW THIS IMAGE WAS CREATED:

I had the rare experience of actually starting the image knowing what I wanted. 
The dive was fresh in memory and I had already decided I was going to try to 
model that incredible spot when I saw this round's topic a couple days later.

I had scribbled a map of the spot in my logbook, so I made a rough sketch in
PSP, then imported it in Bryce's terrain editor and built my heightfield.  I 
used the dimensions of the terrain to set my scale and water plane. The camera 
is at 45 ft.

The anemone's body and the spongoids in the foreground are Bryce metaballs, 
the rocks are Bryce terrains and lattices, and the urchin spines were done 
in LSystem 5.  Everything else modeled in HamaPatch.

The kelp is several leaf clusters made in Hamapatch combined in various ways 
to make the tall stalks. A few stalks showed me this would be far too many 
polygons, and would take forever to render, so I rendered several clumps,  
rendering them first as a mask render, then as a normal render with black 
background. I made 9 different renders.

I then brought the rendered clumps back in as image maps on transparent 2d 
squares, using the mask renders as the alpha channel.  I arranged the squares 
in three layers to give them depth and so they would leave some shadows. I 
was quite happy with the way that came out.

Textures are all made by me.  Algae on the rocks, and starfish textures are 
seamless tiles  and bumpmaps made from actual photos from the dive.

Lighting was mainly deciding between realistic or artistic so I split the 
difference.  The background is as your naked eye would actually see at 45 ft, 
reds and yellows filtered out by depth, with soft dark shadows.  No caustics, 
sorry, in the real world the light is almost purely diffuse by 30 ft.  

The foreground is lit as though my buddy has shone her dive light on it to 
bring out the colors.

The sunlight is a grid of 6 volumetric radial lights just above the surface 
with a ranged gradient falloff set to the top of the rocks.  There are 17 
radial lights highlighting the various objects, all with squared or ranged 
falloff, and 4 negative lights on the background rocks to darken the crevices 
and add to the kelp shadows. 

I'd like to thank the voters for the helpful comments about lighting on my 
last entry, I worked at this one to get a much better balance between the 
highlights and shadows.

The final render time was somewhat of a shock, even though there are a lot 
of lights, but I used some volumetric textures as well as the volumetric 
lights and I guess that plus the soft shadows and all the metaballs hurt.  
That and I could probably use more RAM.