On Line
Rob Hays
November 1994
	This months files include a ray tracing software package and
accessories, as well as a security program to protect your disks
from prying eyes.

POV
	Personally, I have always been fascinated by ray tracing
software. The idea that my personal computer can create photo-
realistic images that have no basis in reality still amazes me.
Persistance Of Vision is a multi-platform ray tracing package
that is copyrighted freeware. This means that the authors retain
copyright ownership of the program, but no fee is requested.
Versions of the POV program are available for IBM compatibles
and Macintosh, in addition to the Amiga version. POV is based on
an earlier program named DKBTrace, and is the product of a large
programming team headed by Chris Young.
	Two separate versions of the POV program itself are included
in the distribution archive, one for systems with a math co-
processor, and one for systems without. Also included are sample
scenes and the data files used to construct them. The output from
the program is saved to a file in either the program's own
format, or TARGA format. Images can be displayed in HAM6, HAM8,
HAME, or Firecracker modes. Utilities are included to convert the
POV format files to Amiga IFF24, and Amiga HAM6 files. You can
also convert TARGA files to POV or GIF formats for
transportability to other systems.
	Scenes to be rendered are generated from a text file whose
format bears a striking resemblance to the C programming
language. Figure 1 is a 24 bit rendering of one of the sample
scenes, and Listing 1 is a portion of the text file tht generated
the scene. Objects such as light sources and the camera (your
view point), are pre-defined items for which you specify
characteristics. These characteristics include such things as
position, size, or color, and are usually defined with a series
of numbers. More complex objects are built using so-called
primitive shapes, such as spheres, planes, and cylinders
positioned and joined by the program. Also included are more
complex primitives, and textures that can be mapped onto the
surface of an object. Any text editor that will save plain ASCII
text can be used to edit or create scene files. There are more
than 100 of these files included in the distribution archive that
you can experiment with.
	POV by itself is not for the Shell-challenged user as
everything is command line driven. If you are a confirmed Shell-
hater see the next file for salvation. The documentation files
run close to 200 pages, covering everything from setting up the
software to theory of ray tracing itself, and a suggested reading
list for those who want to know more.
	POV requires Workbench 1.3 or higher, and will run simple
files on a system with only 1 megabyte of memory. Currently POV
is at version 2.2.

PovPanel
	If the thought of trying to control all of the complicated
aspects of POV through command lines that can include over 29
switches and modifiers, not to mention filenames and paths,
gives you nightmares, then read on. Colin Bell has developed a
graphical control panel for the POV raytracer called PovPanel,
which is currently at version 1.3 (Figure 2). When started, this
nifty program opens its own window, and through various Intuition
gadgets, allows the user mouse-control of POV's features.
	PovPanel is shareware, the requested fee is a minuscule $5,
and will save you hours of typing command line parameters if you
use POV very much. The distribution archive also includes a small
documentation file to get you up and running in very short order.

LockIt!
	Chances are excellent that there are files on your Amiga
that you would rather keep private. Unless you live alone, there
is always the possibility that someone else using your system may
accidentally or otherwise find these files. How would you like to
come home and find all of your business correspondence erased
through someone's carelessness? The solution is to lock the
files/drawers you want to keep private. LockIt! (Figure 3) from
Andreas Linneman is a program that allows you to accomplish just
this. 
	Once installed, individual files or entire drawers can be
locked. Unlocking requires you to access LockIt!, select the item
you wish to unlock (or lock) from a list and type in the correct
password. Every item in the control list can have its own
password to allow different users access to different files
depending on their needs.
	While the documentation points out that this is far from
absolute security, it should provide a suitable deterrent to the
casual file snooper. LockIt! is freeware, and requires Workbench
2.0 or higher.

Where to look

	I found the POV files on all 4 systems that I frequent,
CompuServe, GEnie, Portal, and Delphi. The file sizes vary
somewhat from system to system, due to different combinations of
files and documentation being uploaded. On CompuServe, look in
the AmigaArts section for the files POV.LHA, and POVPAN.LHA.
GEnie has file #21218, POVAMI.LZH, which is the executables, and
file #21217, POVDOC.LZH which are the documentation files.
PovPanel can be found as file #23625, POVPAN.LHA. The main
program archive is 298,240 bytes, the docs are 218,112 bytes, and
PovPanel is 12,672 bytes. These sizes are for the files on GEnie.
Download times at 2400bps for these files will be approximately
25, 18, and 1 minutes respectively. GEnie also lists several
sample scenes and utilities available for POV. Delphi has the
POV2.2 archive, as well as a couple of older versions. Portal has
the largest collection of POV files, including a version for the
A4000. Use POV as a keyword to search for related files.
	LockIt! I found only on GEnie, as file #22870, LOCKIT.LHA.
It is 18,432 bytes, and should take about a minute and a half at
2400bps.

Where to find me

		R.Hays5		on GEnie
		RHAYS		on Delphi
		72764,2066	on CompuServe
		Rob Hays		on Portal
	InterNet users, the quickest response will probably occur if
you use: R.HAYS5@GENIE.GEIS.COM

	For U.S.Mail:
		Rob Hays
		P.O.Box 194
		Bloomington, IN 47402
	Please include a SASE if you need a personal reply.

	If you run an Amiga specific BBS, send me the information
callers will need to access your system. Phone number(s), modem
speeds, software settings, etc. As a service to the Amiga
community I will include the information I receive in this column
from time to time. Send the info to any of the addresses above.

	That is all for now. Since the next issue is December, I
will start listing some of the BBS information that has been
forwarded to me. This will let everyone who gets a new modem for
Christmas put it to immediate use. See you on line!
