Hi John,
I am happy to hear that the everything went well at
the Nass Conference. I had a lot of fun during the discussions with Fred and Fer
about the dial-concept.
You can make the cone-dial for different latitudes
and longitudes and the apex angle of the cone is independent of the latitude.
With the apex angle of the cone you can manipulate the distance between the
different date-lines. One has to be aware that the date-lines can
overlap for certain latitudes as you will see the compedium
article.
I work in Matlab, I am not familiar with
DeltaCAD but I am sure you'll get it working. If you have any questions
about the algorithm, don't hesitate to ask.
kind regards,
Hendrik Hollander
lat 52 23' long 4 57'
----- Original Message -----
Sent: Monday, August 21, 2006 8:58
PM
Subject: Hendrik Hollander Mean Time
Dial
Hi Fer and Hendrik:
I know I speak for everyone at the NASS
Conference that we were all very impressed with the Mean Time Cone Gnomon Dial
that you helped Hendrik Hollander to develop. Congratulations to
Hendrik for winning the Sawyer Dialing Prize this year. What a
surprise. I knew of Hendrik for his previous work with etched glass and
acrylic dials, but I don't think anybody else knew of him. It
caused a great deal of interest at the NASS Conference since none of us had
ever heard about Hendrik or his new dial before. We loved the
fact that it looks like a simple ordinary dial with straight hour lines,
yet it tells Mean Time because it has a tilted cone gnomon. Fred kept
saying that he wished that he had thought of it. Now that's a
compliment!!! We are all anxious to read more about it in the next
issue of The Compendium.
Afterwards, Roger Bailey and I discussed the
possibility making a DeltaCAD macro for it with the following user
inputs:
latitude
longitude (for longitude correction)
inclination
declination
apex angle of the cone
size
The macro would produce a drawing of the face and
a sideview drawing of the gnomon.
It would be fun to make one of these
someday.
One question: Isn't it possible to make
this type of dial for any plane (horizontal, vertical, inclining and
reclining)?
Congratulations to you both for coming up with
this new sundial design concept and thanks for the handout you made for
us.
John Carmichael
----- Original Message -----
Sent: Monday, August 21, 2006 11:04
AM
Subject: NASS Conference
Hi John,
Nice to hear from you about the NASS
Conference.
Is your suitcase back home? All worry about
these things.
It was a great pleasure to me to get the chance
to present the Sawyer Dialing Prise to Hendrik
Haollander.
It was a pleasant meeting that day in
july.
What do you think about the new sundial he
develloped? I love the idea and I am glad I could be of some help with
it.
Best wishes, Fer.
Fer J. de Vries
Eindhoven, Netherlands lat. 51:30
N long. 5:30 E
----- Original Message -----
Sent: Monday, August 21, 2006 7:40 PM
Subject: Fw: ShadowsPro vs. ZW DXFs
----- Original Message -----
Sent: Monday, August 21, 2006 6:02 PM
Subject: Re: ShadowsPro vs. ZW DXFs
Hi Fer:
I just got back from the NASS conference last
night. The airline lost my suitcase!
Anyway, it was a good conference and Fred
showed a photo of you awarding the Sawyer Dialing Prize to Hendrik
Hollender. Your name came up quite frequently during the
conference.
Once again, thanks for helping me understand
the DXF problem.
take care,
John
----- Original Message -----
Sent: Thursday, August 17, 2006 1:07
AM
Subject: Re: ShadowsPro vs. ZW
DXFs
John,
Your last sentence was:
-----------
Note that Fer's default sundial dimension
settings in ZW2000 are quite large. Could this be why we don't
see the problem (of irregular lines) with the ZW2000 DXF
drawings?
-----------
In my dxf file the numbers are rounded to 4
decimals as 0.0001 or 123.0001
If you enlarge this with a factor 1000 there
still is 1 decimal.
So there is no problem with enlarging a
pattern.
But in general it is better not to scale up a
drawing.
Use real dimensions or scale
down.
Best wishes, Fer.
Fer J. de Vries
Eindhoven, Netherlands lat. 51:30
N long. 5:30 E
----- Original Message -----
Sent: Wednesday, August 16, 2006
11:34 PM
Subject: Re: ShadowsPro vs. ZW
DXFs
Fer: You're a genius!
And Francois: I beg your
pardon!
Fer, I must thank you so much for figuring
out how to fix and explaining the wavy curved line problem.
It's so easy to fix, and makes sense now. It never occured to
me!
The problem is not with Shadows Pro, but
with how I was using it. I incorrectly had used Shadows Pro's
default settings for the size of the gnomon and sundial face. Then
when I put those DXFs into DeltaCAD I scaled them to the sizes I
needed. The wavy lines appeared when I zoomed in and were horrible
when I enlarged the gnomon from the default size of 30mm to the 8
feet required by my project! That was the mistake I made. I
did not know that the default settings produced wavy lines.
I just tested what you told us to do and
you're right! I was able to fix the problem by entering in the
actual correct sundial dimensions into Shadows Pro BEFORE I put it into
DeltaCAD. Doing it this way, as you advised, fixed the
problem! Thanks Fer! And please excuse me Francois for
thinking that Shadows Pro was the cause.
With that in mind, now that we know how to
use Shadows Pro correctly, we should take Fer's advise and remember this
important lesson about making Shadows Pro DXF drawings:
To avoid wavy irregular curved lines
in the DXF drawings, make your original Shadows Pro
drawing using the sundial's actual dimensions or even
larger.
Note that Fer's default sundial dimension
settings in ZW2000 are quite large. Could this be why we don't
see the problem with the ZW2000 DXF drawings?
Anyway, thanks again Fer for figuring out
what was happening, and please pardon me Francois for my
error.
John
----- Original Message -----
Sent: Wednesday, August 16, 2006
12:59 PM
Subject: Re: ShadowsPro vs. ZW
DXFs
Hi John,
The accuracy in Shadows is 0.1 mm in the
dxf file as Francois wrote.
For a small drawing on screen, in which
you see the complete dial, this accuracy is too low for the dxf file
and the datelines in Deltacad look bad.
This is to overcome by the following
procedure.
In Shadows always start with drawing the
sundial you want as a large one by choosing large
dimensions.
You only see a part of the dial on
screen.
Then make a dxf file of it.
Scale it back to the wanted dimensions in
Deltacad and the lines are fine.
So it is right to say that for large
dials the lines are fine, but they are bad for small
dials.
Best wishes, Fer.
Fer J. de Vries
Eindhoven, Netherlands lat. 51:30
N long. 5:30 E
----- Original Message -----
Sent: Wednesday, August 16,
2006 8:31 PM
Subject: Re: ShadowsPro vs. ZW
DXFs
Hello Francois:
Thank you for answering my letter about
the wavy curved lines seen on DXF files made from Shadows Pro.
Hopefully in a future version you can fix this.
One thing you said does not make sense
to me. You wrote:
"The only case where the accuracy could
be a problem is if you draw a very small handheld
sundial."
It seems to me that just the opposite
happens. I noticed the irregularity problem with curved
declination lines when I was creating a very large sundial, not a
small one. Since the wavy irregularities show up only when you
zoom in and magnify the drawing, they are more visible on large
sundials not small ones. Does that make sense or am I not
understanding you?
But except for that wavy line problem,
I just want to say that I love the rest of Shadows Pro. When a
client comes to my studio, they love seeing the animated shadow
feature on my computer. I show them how the shadow will move
on their sundials before I make them. Also, I see that you
have incorporated Google Earth for finding latitudes and
longitudes. And there are many other nice little additions you
have made.
John
----- Original Message -----
Sent: Wednesday, August 16,
2006 10:51 AM
Subject: Re: ShadowsPro vs.
ZW DXFs
Hello all
In Shadows Pro, coordinates are
rounded to 1/10 of mm. This should be accurate enough for most
applications. But when you zoom a drawing you can see broken lines
as their ends are on a 0.1 mm grid. This is true with DXF and WMF
exported drawings.
The only case where the accuracy
could be a problem is if you draw a very small handheld
sundial.
This rounding operation comes from
early versions of Shadows and I will probably remove it in a
future version to avoid such aesthetic problems.
Regards
François Blateyron
----- Original Message -----
Sent: Sunday, August 13,
2006 5:17 PM
Subject: Re: ShadowsPro vs.
ZW DXFs
John,
Thanks for your examples that show the
differences in the sundial lines in several programs. It
is to my opinion a matter of number of points in a line and
rounding numbers.
If a sundial line is a straight
line, which is known of course, I calculate in ZW2000 only 2
points and by that in the computer the line also is
very straight. A curved line is calculated as a series of
short lines and saved as a "polyline". In Autocad this is
a single line, in Deltacad however still a series of short
lines.
In the Deltacad macro it is a "spline" which
perhaps is the best. You also can select it as a single
line. Has Deltacad an option to convert a series of short
lines into a "spline"? I couldn't find it, nor the word
"polyline".
In ZW2000 a curved line can be calculated in
two accuracies. One point for every third day or for every
day. The default always is every third day. (Less points,
smaller file.) See option left down in the input
screen. Usual you don't need this extra option.
Well,
any program has its own advantages and disadvantages by what
the programmer has choosen. The same is due for the Cad
programs you use.
Best wishes, Fer.
Fer J. de Vries
Eindhoven, Netherlands lat. 51:30
N long. 5:30 E
----- Original Message -----
Sent: Saturday, August
12, 2006 7:12 PM
Subject: ShadowsPro vs.
ZW DXFs
Hello all who use a CAD
program (cc. Francois Blatyeron):
I just noticed a big difference
in the sundial DXF drawings produced by Shadows Pro and
ZW2000.
When making a sundial drawing
using Delta Cad I have always either used a DC macro or have
imported a DXF file of the drawing from
ZN2000. Recently I upgraded the Shadows free
version to Shadows Pro so that I could make DXF files and use
the other great new features that Shadows Pro offers.
(The free version does not allow you to make DXF
files).
I immediately noticed a problem
with the DXFs produced by Shadows Pro. If you open a
Shadows Pro DXF file in DeltaCAD and zoom in on the
curved declination lines, you will see that, they
are composed of little straight line segments that form wavy
irregular curves, unlike the nice smooth curves that
ZN2000 produces. ZN2000's DXF's curved lines are
also composed of short straight line segments, but
they have a much smoother curve than the declination
lines made by Shadows Pro's DXF.
Another difference I noticed was
in the equinox straight lines. The ZN2000 equinox line
is just one long straight line, but the Shadows Pro
equinox line is lots of tiny straight lines. (makes editing
more difficult)
If you look at a Shadows Pro DXF
sundial drawing in DeltaCAD without zooming in it looks ok,
but when you zoom in, the curved lines look horrible.
This could cause your final sundial to look the same if, for
example, an engraving machine uses a DXF made from a Shadows
Pro drawing.
Maybe Francois can fix this
problem?
John
p.s. Also, in Shadows
Pro, while drawing a horizontal dial, in the "Sundial" tab at
the top of the page, I can not get the "Declination Lines
Option" pop up page to function. The page
comes up with all the available options, but nothing on the
page functions.
--------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
__________
Information NOD32 1.1703 (20060811) __________
Ce message
a ete verifie par NOD32 Antivirus System. http://www.nod32.com
--------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
__________
Information NOD32 1.1703 (20060811) __________
Ce message
a ete verifie par NOD32 Antivirus
System. http://www.nod32.com
--------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
|