SPACE 2/SPACE - Library 2 - Volume 1.iso/apps/14/general/cad3d.pre

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TOM HUDSON'S CAD-3D: BETA TEST REPORT

by JACK P. DURRE'

I personally consider Tom Hudson, author of DEGAS ($39.95, Batteries
Included), one of the premier Atari programmers, and was delighted to be
offered a chance to beta-test Tom's ambitious new CAD-3D program for the ST.

CAD is an acronymn for Computer-Assisted Design, and it is to the drawing
professions what a word processor is to the writing professions, or what a
spreadsheet is to professional number crunchers.

My main computer interest has long been CAD.  Those of you who know me solely
as an Atari users group officer with DAUG and W.U.N. may not be aware that I
earn my livelihood as a registered Architect.  I've been in practice since
1971 and have my own office in Miami, Florida.

I was fortunate enough to have gotten a sneak peek at CAD-3D back in November
at the COMDEX show, when Tom had barely begun working on it.  Much progress
has been made since.  However, certain features were not yet implemented, and
it should be noted that the following is a report of my experience as a beta
tester -- not a review of a finished product.

At this writing, Tom is in the final stages of clean-up and CAD-3D is
scheduled to be available from Antic Magazine's Catalog by the time you read
this.

CAD-3D takes full advantage of the GEM system of drop-down menus, windows,
sliders, etc.  The main screen is grouped into four separate windows --
Camera, Top, Right and Front.  Eight different menu titles appear across the
top of the screen, including Desk, File, Modes, Views, Light, Generate, Merge
and Objects.  As you work with the program, you will soon discover how
intuitively each of these things seem to work.

PERSPECTIVE

CAD-3D can create a perspective view, as it would actually be seen by an
observer, utilizing orthographic projections.  Huh?  Sorry, suffice to say
that by using the top (plan) and side (elevation) views, as might normally be
drawn by a designer, it is possible to create a "real" picture of a view that
one might actually expect to see.

CAD-3D is capable of doing this in several different forms -- which operate at
different speeds.  In Wireframe mode, each edge of an object is represented by
a line (wire).  Lines which are behind other surfaces and would not normally
be seen can be removed, with the hidden-line option.

Most importantly, CAD-3D can draw solid surfaces that actually reflect light
varyingly, depending on their position relative to a light source, or sources.
Outline, another mode, allows for a solid form including surface contour lines
that lend more understandable shape to surfaces.

The built-in lighting option allows for placement of as many as three
different light sources plus ambient lighting.  Each light source can be
assigned an intensity value ranging from 0 to 7.

CAD-3D can be operated from the keyboard.  However, I found it preferable to
use the mouse, clicking on individual windows to select them for manipulation.
All four windows can be active simultaneously, but this does slow operations





somewhat.

It is possible to select which of two views, such as top or bottom, will be
seen in a particular window.  But as you grow more experienced with the
program, fewer windows seem necessary.  It is also possible to fill the entire
screen with any one of the windows.

INTUITION

Manipulating these windows seems intuitive, at least for the experienced ST
user.  For example, the sliders in the side and top windows are used for
either of two purposes.  In Scaling mode, they are used to increase or
decrease the size percentage of object(s) within a particular window.
Clicking on the upper-left "button" changes these sliders into rotation
controls.

In the Scaling mode, a click in the slider-bar area between the button and
either end increases or decreases the scale (horizontal or vertical size), by
10% percent per click.  Clicking the arrow at either end of the slider-bar
makes the changes at only one percent per click.

You can, of course, drag the slider itself and make size changes up to 50
percent at a time, or rotational changes at up to 180 degrees per use.  This
same coarse/fine control applies to the rotation option, with either one or 10
degrees changed with each click of the mouse button.

In the camera window, the horizontal slider affects the zoom (magnification)
while the vertical slider alters the perspective, but the same rotational
control is still used.

I found it quite simple to scale (size) an object up or down, in all three
axes.  However, without any guide to the relative proportions of the views,
the program loses some of its practicality.  Tom has indicated that he will
attempt to include some means to measure the proportions, allowing the
designer to effectively measure the three dimensions of a shape and convert
those proportions into real-world sizes.

Obviously, one of the more important facets of a CAD program is its Drawing
(generate) mode.  CAD-3D uses two different processes -- Spin and Extrude --
to create the basic shapes needed by an artist or designer.  A grid with
optional "snap" is also available.

PRIMITIVES

Provided as primitives are three different sizes of spheres (each having a
different degree of fineness), a torus and a cube.  (I would suggest at least
one more, a wedge.)  Using these various objects challenges your skills when
first learning the program.  For example, you could select the cube primitive
and stretch it horizontally while smashing it vertically, to create a flat,
thin, groundplane surface.

This is somewhat like squeezing and smashing modeling clay, but with a great
deal more control.  Having created a base surface, you can now Extrude an
irregular object (a pentagonal prism, for example) and place it upon the base.
The Extrude window is divided into four quadrants, with three menu choices
across the top of the screen -- including "rubberband."

The Spin option creates rounded shapes composed of curves, spheres, arcs and
the like.  Using either a "connect" option or the rubberband, a sectional view
of an object is created on one side of the vertical axis and the computer
generates the opposite half.






Most design objects are composed of multiple primitive shapes.  You can create
each portion individually, arrange them into the proper form, and then join
them into one single object. It is also possible to create new shapes by
subtracting one shape from another.  This Generate section of CAD-3D is likely
to both frustrate and fascinate users.

Suppose you wanted a rectangular shape with a sloped upper surface.  One way
to create this would be to extrude a triangular object and revolve it by 90
degrees before placing it on a cube shape.

I've puzzled over pyramids (a cone, actually, with only four vertices), cubes
with holes through them (still working on that one) and other complex shapes.
Still, CAD-3D offers a way to remove the burdens traditionally associated with
drawing realistic pictures while presenting the operator with new challenges.

Obviously, you could add elements to a drawing until a final result is
achieved.  Once a group of individual objects is complete, you could relocate
the entire group within various windows by electing to "drag all",  or you
could drag one object at a time.  These options can be done in one or two
dimensions at a time.

SUPER VIEW

The Super View selection creates a full-screen view of the object(s).  With a
color monitor you can choose two colors in seven shades, or one color in
fourteen shades.  Monochrome systems have an option of black on white, or
white on black.  With CAD-3D's Animate feature, you can select different Super
Views of an object to create a series of "slides."  Imagine an Architect
presenting to the client a series of views that seem to approach the building,
enter it and move around within.

Also, CAD-3D can save pictures to other ST graphics formats for further
enhancement.  You can select DEGAS, NEO or the Antic Catalog C.O.L.R. Editor.

A major criteria for professionals working with CAD programs is their speed.
At times it seems to tax the calculating abilities of the 68000
microprocessor, with re-draw times sometimes running 10-15 seconds for a
minimal change.  Of course, as far as the computer is concerned, extensive
changes require the same amount of drawing as simple tasks.

CAD-3D works with the 520ST or 1040ST.  Obviously, additional memory allows
more complex objects to be stored.  Presently, the total number of separate
objects CAD-3D can handle is 20, but this can be increased by using the Joint
and Merge options.

This preview may seem rather lengthy to the non-user.  In reality it is
pitifully brief.  Tom Hudson's CAD-3D is a complex and serious tool.  It has
even more features, which I have only hinted at here.  For those of us needing
a professional drawing program, it is wonderful!  For anyone else, CAD-3D
provides an easy way to accurately draw objects more complex than ever seemed
possible!

Fully utilizing CAD-3D requires the ability to think in three-dimensional
space, and it could be frustrating for those unable to do so.  There is,
however, probably no better way to learn three-dimensional thinking than by
using CAD-3D.  This program should be in the office of every Architect,
Engineer, Interior Designer, Contractor  and Commercial Artist, to mention
only a few!

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