EMAIL: marvil@algonet.se
NAME: Martin Vilcans
TOPIC: School
COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT.
TITLE: Bloody school
COUNTRY: Sweden
RENDERER USED: Povray for Windows 3.0
TOOLS USED: Paint Shop Pro, paper and pencil
RENDER TIME: 2 hours
HARDWARE USED: Pentium-166, 32 MB

IMAGE DESCRIPTION:

A pair of glasses on the floor of a high school corridor. Perhaps it's the
principal's glasses, as his office is nearby. But why are there blood
stains on the floor? And who is that person behind the door? Who knows?
I don't. I really don't know how I came up with the idea for this image.


DESCRIPTION OF HOW THIS IMAGE WAS CREATED:

Once upon a time, perhaps in 1993, I experimented a little with a raytracer
called DKB-trace. I made the usual balls on the usual checkered floors for
a while, then I made a simple trace of a castle, completely made in stone.
It didn't look very good at all, and I had no time to do anything more. So,
years passed and I did no more raytracing. Then, recently, I thought it
would be fun to try it again. I downloaded DKB-trace's successor, POV-ray,
and started thinking about a nice picture to make. Then, I found the
Internet Raytracing Competition, and that helped me get going. The current
subject was "school", and the deadline for entries was just a week away.
So, I spent a few nights on making this picture, and once again felt the
joy of creating a world with the keyboard.

First, I made the door. It's made of a standard tree texture with a little
reflection added. The window is slightly transparent, so you can see the
shadow of a person behind it. The shadow is an image painted in Paint
Shop Pro. The text on the window is made with the text command.

The floor has a granite texture, and a little bit of reflection makes it
look like it's been recently cleaned. I use a normal with a low frequency
bump pattern, so the floor doesn't look unnaturally flat.

The glasses consist of a few toruses and cylinders. The lenses are made out
of an intersection of three spheres: one for the front side of the lens, one
for the back side (inverted) and one to clip the other two. The back side
has a larger radius than the front, making the lens thinner in the middle.
The crack in the left lens is made with a very thin box with a lower filter
value.

The moon contains of a sphere, a light source and an emitting halo.
Behind the corner in the far end of the corridor, there is another
instance of the shadow image. I added it because I wanted the light and
shadows on the wall around the windows to be more interesting.

The puddle of blood is a blob object intersected with a thin plane. It's
red. Certainly.

To get an interesting perspective, the camera is located near the floor,
pointing a little bit upwards, and is tilted. I used rotate commands
instead of the look_at directive to point the camera in the right
direction. This required a lot of trial-and-error until I got the angle
I wanted. Then I moved the glasses until they appeared in the lower
right corner of the picture - I wanted the composition to be tight.

I used a special formula in the angle directive of the camera. Given a focal
length, it calculates the picture angle. This is because I'm more used to
thinking in terms of focal length instead of angles. For this picture, I
used a focal length of 24 mm (really wide angle). (The number 18 in the
calculation is half the width of a 135-film negative, which is 36x24 mm.)