Strokes and sizes in Illustrator CS on Windows XP

[Dominique_Haumont@adobeforums.com]

Bonjour,

Can somebody help me?
I don't understand what happens.

1) When I create a object and give it a stroke value, it modifies automatically the size of the object.
2) When I want to give a size in the transform (? in French "transformation") palette, the size changes automatically. For example, if I put 200 mm value, it becomes automatically 199,997 mm
3) When I move the object on the working space, the size changes too.

I tried to uninstall and re install Illustrator, it doesn't work better.
I don't understand

I'm on Windows XP Pro, with Adobe Creative Suite Premium

Thanks for help, and sorry if I'm not clear, my English is not good enough to explain technical troubles...

Dominique

[Timothy_Foolery®@adobeforums.com]

Terri Pettit explained this a while ago. It had something to do with the way milimetres, etc. divided into pixels (I think, I can't really remember)

if I put 200 mm value, it becomes automatically 199,997 mm




Does it really matter?

[Dominique_Haumont@adobeforums.com]

Yes, it matters, because it's not always the same. Sometimes it's 199,997 but sometimes, it's 200,003 or something else. When I need to match or align several objects...
An d when I modify the stroke, it's more important, about sometimes 0,5 mm.

And I forgot one thing: the "x" axe of the document is never on 0; always on -0,35 mmm. If I put it on 0 and save like that, next time I open, it' on -0,35 yet.

But somewhere you're right, Timothy, I don't have any trouble if I choose "pixel" in the preferences in place of mm or inches.
But making plans or drawings with pixels is not so easy.
It was not like that on Illustrator 10.

Is it possible to find somewhere the explaination of Mr Pettit?

Thanks for attention
Dominique

[Timothy_Foolery®@adobeforums.com]

Ms Terri Pettit is one of the Adobe engeneers. She's always very helpful, but I haven't seen her in here for a while. I'll have a quick search in this forum for the answer, but if I can't find it I'm sure someone will be able to help soon.

[Jacob_Bugge@adobeforums.com]

Diminique,

Right now I get a connection error 1557 each time I try to forum search, but when it starts working again, you may find the thread Timothy has mentioned if you search this forum for the words 'teri pettit' or '99,99' or 'jacob bugge graphic' it should pop up as one of the first posts.

However, the thread was about how four digits after the comma make the positions funny because the last digit was changed by 1 (I posted that I had seen it on the third digit, such as 99,999); but it did not deal with larger errors such as 199,997, not to mention -0,35.

I regret to say it, but you may have to use the great invocation: deleting the AIPrefs file, see FAQ item #4.

[Dominique_Haumont@adobeforums.com]

Thank you Timothy and Jacob,

I will try and hope to find Ms Pettit.
I tried to delete the Aiprefs, and also the Adobe_demar, but it doesn't change anything
I tried to change the settings of decimals in the Window system... do the same...

Best regards,
Dominique

[Dominique_Haumont@adobeforums.com]

By the way, Jacob,
I get the same message error 1557; what does it mean?
Dominique

[Jacob_Bugge@adobeforums.com]

Dominique, I think error 1557 means that the search function is out of order. I will post it as a new topic.

[Rick Moore]

FYI, this is Teri's post regarding the topic:

"Illustrator internally stores all coordinates in points. So if your display
units are not points, the actual measurement must be multiplied by a
conversion factor to get the displayed measurement. There is a conversion
going on for inches, too, but since an inch is 72 points, which is divisible
by 8, most common inch measurements work out to an integral number of points
anyway, or at least a binary fraction of points (like half points or quarter
points.) The conversion factor between points and millimeters, however, is
only an approximation, so when you enter a value in millimeters, then
convert it to points in order to actually create the object, and then
convert it back to millimeters (or centimeters) to display it again, you
rarely get back the exact same value.

The only thing that changed in Illustrator CS was that most of the palettes
and dialogs now display values to 4 units of precision instead of 3 units.
This was a popular feature request (search the forum on "precision" or
"digits"), mostly by people who wanted to enter values such as 0.0625 inches
(1/16 inch), and have it display as 0.0625 inches instead of 0.063 inches.

The actual width of the object has not changed, you are just seeing more of
the imprecision in the points-to-millimeters conversion factor than you
could see before. I'm not sure why the displayed accuracy changes as you
move the object around, since I think the Transform palette gets the
selection bounds in points and differences the edges to get the height and
width in points, and then converts that to the display units, rather than
converting the left and right sides independently to millimeters and then
differencing them. Probably it has something to do with the zoom level
causing the movement to not be an even number of points, so that at some
positions the coordinates round differently. Does it seem to make a
difference what zoom level you are at when you are moving the objects?"

--


Rick Moore
Barnes Gromatzky Kosarek Architects
512 476 7133
[url]www.bgkarchitects.com[/url]

[Dominique_Haumont@adobeforums.com]

Wow! Thank you, Rick, for your help.
I begin to understand.
But I think now that there are differents troubles, and not only one.

About what you say, I understand, but I tried with points units, and it moves in the same way: 200 pt became automatically 199,9995 pt or 200,0005 pt. And changes when I move the object on the working space.
And effectively it seems to be different at different zoom levels, but variable results.

The trouble of scales seems other: it's always the same: the "x" axe is always on -0,3524 mm (or 0,999 pt). But not the "y" axe, always on the 0.

And finally, the size change all the time when I put a stroke value. It seems that the object add this value to his size, even if I don't vectorize it....

I will go and see the posts you told me. May be, I will find something to help me...

Thanks a lot,
Best regards,
Dominique

[Pierre_Courtejoie@adobeforums.com]

Bump... What would be the best workaround for Dominique, then?

Work in Pixels???

[Jim_Sommer@adobeforums.com]

I received files from a customer that was using CorelDraw and saw a similar situation. In order to output film to the exact size specifications from Illustrator 10, I needed to change a set value in the file of 13.000 x 70.500 to 12.995 x 70.510. At times, the values would transform as requested but at other times they would vary by 1 or 2, plus or minus, in the 3rd decimal place.

I had originally thought that it may be a rounding error (window XP pro). I then checked a number of files that would transform properly and others that would not to isolate the problem.

All of the jobs that would not transform properly were created from a 'template' file while the others were created as new leading me to think that something was left behind in the template file causing the error. A file in Illustrator 10 that has all fonts as outlines will still present an error that fonts are missing if opened on a machine that soes not have the particular font installed.

JCS