|
This paper discusses
some of the issues involved in choosing and implementing CAD software.
The
availability of low cost CAD software has radically changed
the
way professionals work.
Most project managers now expect that some type of CAD software will be
used to create drawings describing
design work. Managers and clients also assume that the work
you do, will be delivered in both printed and electronic format.
So, in most
design professions, producing design work on
paper drawings alone is no longer acceptable; you really need CAD.
This change in attitude has major implications for many
of us. If you are working, or intend to work, in the Architecture, Engineering or
Construction industry, you need to be able to produce CAD drawings if
required. It goes without saying that you need to learn to do this
efficiently, making the CAD software work hard for you, not the other
way around.
Learning to use CAD software is not a trivial task.
You really need to allocate some serious time to acquiring a new
skill. The news is not all bad though, you will
have a marketable skill. Simply purchasing expensive CAD
software will not make it easier to learn.
We suggest
downloading free CAD software that mimics the way the
CAD market leader (AutoCAD) works and access training materials
on the Internet before putting any money down. An example is
Windows software
called GardenCAD, which although it is focused on the needs of
landscape architects, it can be used to make CAD drawings in any
discipline.
Visit
http://www.gardencad.net
to get a copy of GardenCAD. GardenCAD, it is
functionally similar to AutoCAD and IntelliCAD (the commands and
method of operation are almost identical) and it can be used in any
design field.
GardenCAD works on Intel based Macintosh computers using the
CrossOver plug in so you can certainly experiment with CAD on
your Mac.
The CAD designs shown below were produced using GardenCAD.
 |
|
Detailed
landscape design. |
 |
|
Mechanical
services drawing |
 |
|
Instrument loop
drawing |
|
 |
|
Simple garden
design plan produced using GardenCAD. |
|
 |
|
Here a hand
sketch and some images of suitable plant were assembled in
GardenCAD using the insert raster tool. |
 |
|
More complex
landscape design |
So, you can gain some considerable experience in CAD
and get access to a comprehensive suite of training materials
(including many on-screen movies that show how things have been done)
by visiting www.gardencad.net
or
http://www.dcad.designcad.com.au. At a later stage you may
want formal training. Visit our online learning site at
http://www.softwaretutor.designcad.com.au
There are many different CAD programs on the
market – AutoCAD, AutoCAD LT, GardenCAD, Caddsman,
IntelliCAD,
Design Cad 3D, TurboCAD, Qikdraw, Catia, Solidworks,
IronCAD, MicroStation, MiniCAD, Foresight,
LisCAD, WESCOM, to name but a few. They all have various strengths and weaknesses. Perhaps the most
important thing to note is that they mostly save their drawing file in different
file formats, variously called .DWG, .DGN, .CTA, .VEC, .AI, etc. Because the file formats
differ, moving data from one CAD program to another is not necessarily a trivial
task, so you need to 'get it right' when making the choice of software
for you or your company,
especially if you need to accept work from others and pass your work on
to associates.
In selecting CAD software, our advice is to
first define where you or your organization sits in the ‘flow of information’ for the
design work that you carry out. This will be different for each business. A firm of
mechanical engineers who manufacture their own products and designs and develop
‘in-house’, can choose any CAD program that suits their needs; they don’t
care what others are using as long as the software they choose suits their staff and the
job is done efficiently.
However, others such as landscapers architects and
garden designers, by the very
nature of their profession, must recognize that they are invariably dealing with drawing
files that come from other design professionals (surveyors, civil engineers, architects
etc). Thus there is a need to consider not only their own requirements, but it is critical
to be aware of the CAD software that others in the 'supply chain' are using.
Most vendors of CAD software will tell you that
they have included an export function to create what is called a Drawing Exchange Format (DXF)
file which makes drawing translation a simple task. Be aware however
that the
translators providing for the generation (and importation) of DXF files are not
perfect and do not deliver seamless translation.
As an example, most CAD programs do
not understand polylines used by IntelliCAD and AutoCAD. These get converted into short line segments
as the DXF file is generated. Flexibility of editing in a subsequent drawing session
in the 'receiving' environment is
then compromised. This drawing file incompatibility issue is
not a trivial concern. We have experience in a job where profitability was severely compromised
because (as we discovered at a very late stage) the survey software used for the base
drawing (WESCOM) uses AutoCAD text shape files to place tree symbols – letters
appeared in the AutoCAD drawings where we expected to see existing trees. Many hours were
lost trying to track down the source of the problem.
Many CAD programs now claim the ability
to open DWG files without conversion. Again, be wary of this claim; try
this claim by downloading a trial version of the software before you buy. There may be an ability to do this, but the software may
not open the DWG files generated by the latest release of AutoCAD.
There may be tension between your needs and
those of the supply chain. On the one hand, you may want the ability to implement 3-D
rendering, to output rendered images in a format suitable for a commercial printer, the
capability to paste aerial photographs as a backdrop to your drawings and the ability to
smoothly work with multiple views of drawing files which are greater than 10 Mb in size
(in a design for a very large wetland for instance).
In our opinion, MicroStation software, from Bentley Systems,
certainly meets these criteria far better than does Autodesk's AutoCAD or
IntelliCAD. However, in
many states of Australia, MicroStation has less than 10% of the market share (in Western Australia
MicroStation holds >50% of the market) so you might have to eliminate MicroStation from
your list of potential CAD programs, because it is unlikely to be used in your supply
chain.
As mentioned the first step in choosing CAD
software for landscape professionals is to look at the local market and then at your own
supply chain.
In most states of Australia there is no question that
IntelliCAD and Autodesk’s AutoCAD software dominates the market.
[In the US, MicroStation and AutoCAD run nearer 50:50.]
Our guess is that in Australia, >80% of CAD
files are created in .DWG format used by IntelliCAD and AutoCAD in these states. This leads
to the
conclusion that after downloading and trying out the free CAD
software and getting a feel for CAD, the first piece of software purchased for a landscape office operating in
Australia could be IntelliCAD (cost around $A300.00). A
second choice would be a copy of the Lite
version of AutoCAD - AutoCAD LT (cost around $1200).
Suppose that your supply chain is a little
unusual in that 50% of your work comes from a firm of architects who used to use
VersaCAD
on Macintosh computers and now use VersaCAD on a Windows computer. Ask yourself the following questions.
"Are you getting drawings from these architects presently? Do they work well enough
in (say) the IntelliCAD/AutoCAD environment you currently use (through DXF exchange)? Is it
absolutely crucial to have at least one copy of VersaCAD in your office?" "Is
there a pool of qualified landscape architects who are VersaCAD competent who you can
draw on for a project?" "What would be the real cost if you had to complete a
project entirely in VersaCAD? "
Having established that the .DWG format used
by AutoCAD and tried out IntelliCAD and the Lite version of AutoCAD, a choice then has to be made between
buying the full
AutoCAD (at $6000.00) - perhaps so you can do 3-D modelling and another copy
of AutoCAD LT or IntelliCAD (see below). We are biased, but stress the
need for training. You can then get some training either in-house or
via distance learning. Alternatively, for a single man office, GardenCAD Pro ($AUD49.95) offers a
very low cost solution, especially as you can try it out for free with
access to an extensive set
of online training materials.
Now it is time to look at your own specific
requirements more closely. If you have chosen AutoCAD, you need to decide which version of AutoCAD will do the job for you? The list of
questions below (in no particular order of importance) should assist in decision making.
Image files:
Is there an absolute
requirement for pasting carefully registered scanned images into drawings? In AutoCAD,
images can be placed in drawing files, but, like XREFs, they are not actually part of the
drawing file. The image is linked to the drawing file through a path name or a data
management document ID. Linked image paths can be changed or removed at any time. By
attaching images using linked image paths, you can place images in your drawing, only
slightly increasing the drawing file size. Early versions of AutoCAD LT did not have the
ability to load this type of composite drawing, but LT now does with some
limitations. If you need
this feature, then perhaps you can get an associate company with a full AutoCAD to
create the base drawing with its attached image files and then use LT for your design
work. LT can handle pasting .GIF, .JPEG and .PCX files into a drawing, but it may not give
you the degree of control that you are after.
 It pays to keep checking on the features
in the current version of AutoCAD LT, it tends to leapfrog the full AutoCAD.
The development of IntelliCAD and BricsCAD is also remarkable.
Programming:
AutoCAD LT is not
programmable. Ask yourself "Do you have a requirement for using any of the
programming languages that come with the full AutoCAD (AutoLISP, VBA, ARX etc.)?" If you
choose LT then you cannot run (say) a program to read a data file of points and create a
(rectangular) surface mesh with facets to give you the surface topography of a site
including contours. In the same way, you cannot use AutoLISP to create a new command (we
call it VERIFY) to enable you to audit a finished drawing against a project or company
standard. the VERIFY command checks fonts and blocks used, layer names etc. The ‘Pack
and Go’ feature of AutoCAD is a great feature where project files are being
exchanged, but relies on AutoLISP being present.
3-D Design:
Do you need to work in 3D?
You may like to, but have you got the skills now? AutoCAD LT can read and display drawing
files with 3D information in them, but it cannot create some very complex 3D shapes. Can
you create and manipulate these complex 3D shapes in the full AutoCAD now, or is it a pipe
dream? Do you need solid modelling?
Rendering:
AutoCAD LT does not allow
rendering (creating photo realistic 3-D images with light sources with (say) a sky) with
clouds as a background. Before you say 'yes I must have this feature', are you willing to
spend the time to learn to draw in 3-D? It is not a skill quickly acquired.
Is there and
alternative? Can you learn to use your digital camera more effectively and then use
Photoshop to dress up images, pasting them back into AutoCAD for final presentation? Maybe
you can learn to build simple 3D geometry as a wire frame image and then 'dress it up'
using Paint Shop Pro. SketchUp might be a better alternative. The figures
below shows a garden and warehouse design created in SketchUp.
 |
|
Model created
in SketchUp (by Yardstick Designs) |
Cost:
How much money does your budget allow? Each CAD seat needs a software licence. The full AutoCAD has a hardware
and/or a software lock, so
you can have the program loaded on several computers and simple move the lock around as
needed while AutoCAD LT and IntelliCAD need to be licensed for each
computer on which they
are loaded.
Each office to purchase one (1) copy of the
full AutoCAD ($A6000.00+). Subsequent CAD seats to be AutoCAD LT (upgrade earlier
versions of LT to current AutoCAD LT). watch out for recurring
'maintenance' charges from AutoDesk.
Each office to purchase copies of AutoCAD LT for each CAD seat - (upgrade earlier versions of LT to AutoCAD LT). Strike an
arrangement with a consultant to use the full AutoCAD should there be a need for
programming (base maps containing images, generation of surface meshes, calculations of
cut and fill volumes etc.). Purchase one (1) copy of IntelliCAD to be used across both
offices so that staff can experiment with 3D model making, rendering and output to
film. When capability clearly demonstrated, move to a single copy of the full AutoCAD.
Buy a single copy of IntelliCAD
and spend money on training either group or one-on-one or via
distance learning.
Note: Be very aware that Autodesk
(the publishers of AutoCAD) want you to stay on an upgrade path. As an example, in July, 2004 we
were told that we only had 6 months to go before we are unable to upgrade our copy of
AutoCAD 2000 to 2004. AutoCAD 2004 will not write out files to early
versions of AutoCAD. Even in 2011, Autodesk, still adopt this draconian system
of forcing users to sigh up to an annual maintenance agreement.
Use GardenCAD Lite or dCAD and access free training.
|
