[Pythoncad-developer] Notes on Pythoncad and drawing

[Yagnesh D. <yn...@gm...>]

Dear Friends;

Following is the note from Mr David Young whose request I
found received by email and helped him download pythoncad
ver R38 for testing, I am trying to have him on our group but
till then following is his note for the record

Quote:

Notes on Pythoncad and drawing


David Young


I am a professional architect (building design and construction),
having completed my degree in 1976. I started electronic drawing in
1989, and have used Cadam (originally from Lockheed) and its later
Helix version for most of my technical drawings since 1989. An
offshoot went into Catia (Dassault Systemes) when Cadam and Helix
support terminated outside Japan. I have been trying to learn to use
Blender, and have done some translation of manuals for gCAD3D. I had
started looking at Python (I have done some web and intranet work with
PHP) when I came across the Pythoncad site, and thought the idea was
interesting.


Some asides:

There are a number of FOSS and similar CAD and modelling programmes
around, but each seems to be incomplete in various ways, or perhaps I
do not have sufficient understanding of how they work.

The idea of a standard type of file format (OCA) seems good, in that
the aim is not to work around the Autocads, but to make a useful
product which stands on its own and can import and export readily.


Pythoncad communications:

>From what I have seen, there seems to be a need for better
communication for the project. The Sourceforge site is fine for
downloads and development, but it seems to me that there needs to be a
current web site and wiki type facility (I get a dead end clicking on
the wiki link on Sourceforge, and the link to the web site which
points back to Sourceforge is not helpful).


The download packages need to be complete, with instructions, and with
pointers to help. Without this, the project creates a bad impression.


Drawing in general

The least moves and clicks to get the most accurate data on to each
drawing is the aim.


I can only try to generalise from my experience.


Interface:

Needs to be as customisable as possible.


More useful items need to appear on the display. One feature with
Cadam is that a short list of next possible actions is given on
screen.


The three-button mouse gives a potential six actions, plus scaling
using the wheel. Must work for left and right hands. Inner button,
middle mouse, outer button, inner+outer, inner+middle and
outer+middle.

Cadam uses 5 of these, and has its own consistent usage of 'select'
(inner), 'indicate' (middle) and 'yes/no' (outer) plus 'window' (one
2-button combination) and 'pop-up menu' (another 2-button
combination).


Because the list of functions and actions neccessarily gets long in
order for the software to be useful, one potential thing from Cadam is
that each main function appears on the pop-up menu, with sub-menus
appearing in context relative to the function.


Output must be plottable to scale on paper for the software to be usable.


It is necessary for a drawing to be able to include a variety of
scales and rotations of work, and plotting must handle these
correctly.


Analysis of existing points, lines etc must be quick and easy.


There must be access to standard symbols and details. 1989+ Cadam
allows dipping in to any drawing on the network to extract details for
use in your current drawing.


And things like area fills are essential for use of the software. I
will give a detailed list of Cadam functionality when time permits,
just as a checklist of things needed in useful software, as well as a
bare-bones minimum list.


Backward compatibilty is highly desirable for me. Cadam has removed
limits and added features, but one can open the oldest drawing and
save it as a current model.


There is no end to what is needed to make CAD simpler to use and more
productive. It goes on from 2D to 2.5D (Cadam) to 3D to models with
extraction of 2D and 3D sheets (Archicad etc). And we are just at the
beginning.



Other comments will follow. All is hopefully seen as positive comment.


David

:UnQuote

-- 
Best regards

Yagnesh Desai