TITLE: Subway
NAME: Michael Hunter
COUNTRY: USA
EMAIL: intertek@one.net
WEBPAGE: http://www.interactivetechnologies.net
TOPIC: Speed
COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT.
JPGFILE: subway.jpg
RENDERER USED: 
    3D Studio Max Version 8

TOOLS USED: 
    3D Studio Max, PhotoShop (for texture maps)

RENDER TIME: 
    subway station 6h 21m, Car interior 1h 11 m, Man and foreground
seats: 25m

HARDWARE USED: 
    Pentium 4 1.8 GHz 261 MB RAM

All of the objects were modeled and textured by me for this competition with the
exception of the photographs that appear in the overhead adds. These
photographs have been provided by freephoto.com.


IMAGE DESCRIPTION: 

Happy New Year everyone!

I've been criticized for being to long winded in my descriptions so I will try
to be brief.

This is a picture of a Pullman R46 subway car used in New York (at least that's
what was rolling when I lived there 14 years ago). For sure there are lots of
things that go faster than the subway (top speed of this type of car is about
65 mph or 105 km/h) but there's more to a subway that it's measurable speed.
The noise, the rush of air as the car enters the station, the river of people
streaming by seem more like the circulatory system of the city. It's alive and
pulsating with activity.


DESCRIPTION OF HOW THIS IMAGE WAS CREATED: 

I started building the station and the exterior of the subway car. After working
on it for a while my good friend Hildur Kolbrun
(http://www.simnet.is/hildurka/) suggested that I put the camera inside the
train and point it out the window. I hadn't thought about actually making the
inside of the train but I really liked the idea of showing two different spaces
with different lighting in one image. My problem was limited hardware capacity.
I resolved this by rendering the image in stages. First I rendered the station
(the stuff outside the car) then used that rendering as a background and
rendered the interior on top. I really don't think my machine could have
managed it without this process but it also let me workout the problems
independently. While I was messing about with lighting inside the station I was
also building the interior and while I was working out the lighting for the
interior I was building the man which was rendered later on top of the prior
two layers.

To save time, both in modeling and rendering, only what is visible exists. The
car we are in has no external surfaces. The blurry car on the other side of the
platform has just a minor suggestion of an interior. The man does not have a
face and nothing below his shoulders and only three fingers on his one hand.
This scene would look very odd from the opposite direction.

It's not easy to find technical drawings of many things. I was able to find the
length and width of the subway car (75' x 10' or 2286 cm x 305 cm). Somewhere I
read a subway train usually has six to eight cars. So I was able to guess at
the length of the station (8x75'= 600' or 183 meters so the length has to be
longer than that). Other times I had to go by what looked right from photos and
be open minded about adjusting sizes later. All of this bother is very
important if you are going after a natural feeling environment. I measured the
chair I'm sitting on to get a ballpark idea of how high the seat and back of
the subway chairs should be. The size of the subway chair and length of subway
car helped me guess at the size and location of the window. I'm probably off
here and there but overall I don't think there's anything that looks out of
scale.

All of the lights are photometric lights. They more closely mimic the physics of
actual lights than the standard lights. The lights in the station consist of
many linear lights for florescent lights. I used ten area lights within the
car.

There are a great many rendering options within 3D Studio Max. One major reason
for the complication is to provide a means to turn off certain types of
calculations when they are not needed or to adjust the accuracy of calculations
to reduce rendering times. You can turn off caustic reflections or increase
samples of various processes. But the renderer can do more than optimize
performance, you can change the anti-aliasing to give a softer focus or to
accentuate metallic highlights or for other visual refinements. For those using
3D Studio Max: This image was rendered with Mental Ray with global illumination
turned on. I had to turn off final gather as it was causing artifacts after the
addition of some geometry into the scene. I haven't yet found the true cause of
the artifacts.

LINKS:
Photos of the real thing (see bottom left of page for links to more photos)
http://www.nycsubway.org/cars/r46.html 

Home page of the above, includes history of NY Subway
http://www.nycsubway.org/

Interactive subway map
http://www.mta.nyc.ny.us/nyct/maps/submap.htm

Scale map of NY subway and satellite photo of same area
http://www.columbia.edu/~brennan/subway/

Photos of NY Subway Stations
http://www.nycsubway.org/lines/


