TITLE: Escape Velocity
NAME: Glenn McCarter
COUNTRY: USA
EMAIL: glenn@mccarters.net
WEBPAGE: http://www.geocities.com/gmccarter
TOPIC: Speed
COPYRIGHT: I submit to the standard raytracing competition copyright.
JPGFILE: escapeve.jpg
ZIPFILE: escapeve.zip
RENDERER USED: 
    POV-Ray v3.6

TOOLS USED: 

  Pencil & paper (boat design)
  Rhino v3.0 (NURBS for main boat surfaces)
  WCT2POV (convert Rhino .3DS export into smooth triangles)
  POV-Ray editor (scene modeling, lighting, mechanical details)
  Paint Shop Pro (image maps, convert image to JPEG, add signature)


RENDER TIME: 
    44m (background), 6h29m (main scene)

HARDWARE USED: 
    Overclocked Athlon XP 2100+



IMAGE DESCRIPTION: 


July 20, 2007 at the annual "ThunderFest" boat races in Madison Wisconsin.  In a
moment of speed-upon-speed, driver Chuck Stennis narrowly avoids serious injury
when mechanical failure strikes his hydroplane "Viper".  This is the first-ever
use of an ejection seat in a hydroplane racing boat under competition
conditions.

The fully automatic system requires no driver interaction.  On-board computers
track the attitude and trajectory of the craft.  When the systems sense that
the boat has entered an unrecoverable state, it fires booster rockets under the
seat, initiating the ejection sequence.  In 150 milliseconds, the canopy is
jettisoned and the seat clears the rails.  This subjects the driver's body to
enormous forces, up to 20G's, but it saves him from a worse fate: impacting the
water surface at speeds of up to 270 km/h (170 mph).

Moments later, the parachute is deployed.  Stennis drifts back to the water and
is fished out by officials.  The the race is later restarted.  "Viper" has been
completely destroyed.



DESCRIPTION OF HOW THIS IMAGE WAS CREATED: 


This image was rendered in two passes.
The first pass creates the backdrop for the main image.  It is a collection of
simple CSG trees, height_field terrains, and the bridge.  It uses a slight
focal blur in order to de-emphasize the background areas and enhance the
overall sense of 3D depth.

The second pass has all the main details in the scene including the boats and
rooster tails.  It is rendered in sharp focus with antialiasing, while an image
map of the first pass is displayed in the background.  The background image map
is blended at the bottom to create a less jarring transition to the waterline
in the main scene.  Light groups with area lights are used to create soft
shadows in certain areas, without increasing rendering time too much.  I tilted
the camera in this pass in order to heighten the drama.

I tried using media for the rooster tails, but the rendering time was
prohibitively high even with an overclocked PC.  Fortunately I discovered some
tricks to eliminate the media, which increased rendering speeds in this image
by over 100x.  Simple spheres with partially transparent spherical textures
were the basic building blocks.  Macros assembled these into useful structures
such as sprays and plumes.  I used this same technique for the clusters of
leaves on the trees in the background.  The rocket flame and smoke trail,
however, uses full-bloen media effects.

This combination of rendering passes and techniques allowed me to control
certain technical aspects (focal blur, antialiasing, motion blur) to get the
artistic effects I wanted, while boosting rendering speed significantly.  For
details on specific objects rendered in the scene, take a look at the included
zip file.

ACKNOWLEDGEMENTS:
Thanks to my brother, whose hydroplane "speed" ideas inspired me to create this
scene.  I had planned to depict speedy vehicles on land or in the air, but a
sea-based image had not occurred to me.  The ejection seat idea is all mine,
though.  Special thanks to Martin Herker, whose comprehensive website on
ejection seats provided valuable reference information.