Belgian Amiga Club - ADF Collection/BS1 part 05.zip/BS1 part 5/Tracer.adf/ReadMe

Text File | 1992-08-02 | 7KB | 177 lines

12/3/92

Release notes for the 3-D Professional Ray Trace Module V1.00

Welcome!  Please read through the notes that follow for last
minute news and information which is not contained in your Ray
Tracer Manual.

Due to disk space limitations, the "Sample" scene mentioned in
the manual could not be included.  As a replacement, use your
own scene, or use one of the scenes on the Data Disk.  Try the
"Bench" or "Thrones" scenes for starters.


ADDITIONAL FILES INSTALLED

Two additional files (which are NOT listed in the manual) are
copied by the installation program:

   Tracer.fpu
   Tracer.fpu.info (optional)

This is the floating point unit (68020/030 & 68881/882) version
of the tracer.  Either version may be deleted (if you are not
going to use it) after installation; only one version (Tracer or
Tracer.fpu) needs to be present.


SAMPLE DATA

The Data Disk contains some sample scenes and images.  We
recommend that you use this example data to familiarize yourself
with the effects of the various surface attributes.  These scenes
can be of great tutorial value when used in this manner.  There
is a "ReadMe" file on the Data Disk as well which gives brief
descriptions of the example scenes.


THE "STARTUP" CONFIG FILE

It is possible to have a config file loaded (by default) every
time the tracer is loaded.  If a config file with the name
"startup" is in the "Configs" directory, it will be loaded when
the tracer starts.  This way you can customize the tracer's
settings without having to specifically load or specify a config
file for every trace.


DO LOCAL/BATCH TRACES WHENEVER POSSIBLE

We recommend that you use the ray tracer by itself as much as
possible.  While it IS more interactive to use the tracer as a
custom renderer in 3-D Professional, there are many benefits to
using the tracer alone.  Refer to section 8.8 in the Ray Tracer
Manual for more information on local/batch tracing.


THE NEW WORLD REQUESTER

Disregard section 9 in the Ray Tracer Manual.  It is obsolete now
that the "world" requester has been added to 3-D Professional.
Refer to the latest 3-D Professional documentation (should be
1.1) for more information on the world requester.


LIGHT FALLOFF EFFECT

This special effect has changed since the manual was written.
Instead of only affecting light which passes through transparent
objects, it affects ALL light.  That is, all light rays will
decrease in intensity due to distance.  For example, a mirrored
sphere may be reflecting two objects.  With this effect in use,
the object that is farther from the sphere will be dimmer due to
the light falloff.  In the case of transparent objects, light
which passes through will not only be dimmed due to distance, but
also due to the object's index of refraction.  Higher indices of
refraction (hence harder substances) will cause light to falloff
faster.


NETWORK/SERIAL TRACING

When doing network or serial traces, it is usually a good idea
for the fastest machine to be the host.  This will generally
result in a more efficient tracing scenario.


GENERAL PURPOSE ANTI-ALIASING

For good, general purpose, anti-aliasing, try just raising the
"Number of rays per pixel" setting to 4.  And, leave the
remaining settings at their default values.  This will cause the
ray tracer to use only 4 rays per pixel in most areas, but up to
32 in those areas where better anti-aliasing is needed.  Please
note, this will increase trace times.  See section 8.5 in the Ray
Tracer Manual for more information on anti-aliasing.


PRODUCING AMIGA IMAGES

Since the ray tracer only outputs RGB files, you will need to use
either 3-D Professional or some other utility to create an Amiga
image.  We recommend that you output in the IFF format and use
ASDG's The Art Department to convert the RGB file.  The IFF RGB
format is a single, compressed file and is easier to work with
than the others.  And, due to the nature of The Art Department,
it is very good at converting RGB files into Amiga images.


THE "WEIGHTED" PIXEL INTENSITY SETTING

After further testing, it has been found that this option causes
traced images to be of higher contrast.  That is, lighter areas
in the image will tend to appear even lighter in comparison to
the darker areas of the image.  In some cases this is a more
pleasing effect.  For MOST traces, however, the "Uniform" setting
should be used.  This is due mainly to the fact that the weighted
settings requires that more than 1 ray per pixel be specified.
In addition, the weighted setting will cause the trace to take
longer since the number of rays actually used for each pixel will
be the "maximum" in more cases.


EFFECTS OF THE "RAY TERMINATION THRESHOLD"

NOTE:  In the manual, the default for this setting is listed as
"10.0".  Please note that it has been changed to "5.0".

This setting represents one of the less obvious ways to adjust
the "trace time/image quality" ratio.  By default, the setting
ensures that rays are cut off when they no longer contribute to
the image in a "significant" way.  The key word here is,
obviously, "significant".  When traced images are viewed as Amiga
HAM images, they do not have nearly the color accuracy that they
would if they were, for instance, viewed in full 24 bit color.
This is where this threshold can come into play.  By default
(5.0), a good compromise is made between viewing the image in HAM
OR full 24 bit.  You could lower the trace accuracy by raising
the threshold.  This would only be a good idea if you were going
to view the image exclusively in HAM (which may not be able to
show the lost accuracy anyway).  If, however, you are going to
output images in full 24 bit color, you may want to increase
accuracy by lowering this threshold.  As you might suspect,
lowering the value causes traces to take longer, while raising
the value speeds up the trace.  It is not recommended that you
raise the threshold above 15.0.  This would, in most cases,
causes too great a loss in image accuracy and quality.


LIGHTING DIFFERENCES

Due to the nature of the ray tracing algorithm, specifying
lighting for 3-D Professional renderings and ray traces is very
different indeed.  In most cases, a scene which has been both
rendered in 3-D Professional and traced by the ray tracer will
appear brighter in the traced image.  This is especially true if
the scene contains a lot of reflective surfaces.  This is caused
by the fact that light rays are more realistically simulated and
therefore light the scene more "vigorously".  You may not find
that this is a problem.  If so, experiment with a couple scenes
and soon you'll learn to easily compensate for the differences.

REPORT FILES

Every time a ray trace successfully completes, a report file is
written to the "Reports" directory.  Report files themselves are
always named "report" with a numerical extension.  These files
are simple, ASCII text files and can be viewed with your favorite
text editor or word processor.  Among archival and technical
information, these files also contain the trace timings.  Every
now and then, you may want to clear out the Reports directory
as it fills up with report files.  If you do not want these files
written, either delete the Reports directory or rename it
temporarily.  If the directory cannot be found by the ray tracer,
it will quietly (no error will be given) NOT write the file.