Inspiring

Question

Object dimensions are wrong/changing

Forum|Forum|7 years ago
August 23, 2018
7 replies
9838 views

Anybody else having 'issues' with the dimensions of objects being inaccurate in illustrator?

I've set up a document (CMKY and 50mm x 50mm artboard). Snap to pixel is off.

When I draw a rectangle of 50mm x 50mm everything seems good, but when I select the object again the dimensions actually read as 50.003mm. I can change the dimensions either in the control bar at the top, or the transform panel and everything seems accurate, but again if you deselect and re-select the object, the dimensions have again altered to this slightly off measurement.

I've heard some people say that Illustrator uses points and mm / inches etc get converted to points and some 'rounding up or down' occurs, causing this inaccuracy. Granted that kind of minuscule change is barely going to be noticeable, but when accuracy is important it seems illogical to round anything up or down. If units are set to mm, then Illustrator use mm to measure and set and calculate dimensions no?

I've reset preferences, restarted Illustrator (and my workstation) but still happening. Its another example of me constantly finding Illustrators accuracy absolutely awful. Kind of defies the purpose of entering exact values if they are going to be altered?

Rian

M

Moiz Hussain

Participant

make the box as a fill and remove stroke. it will show you 50mm x 50mm. But when you again add the stroke the measurement will increase. So its an issue in Illustrator

Monika Gause

Community Expert

make the box as a fill and remove stroke. it will show you 50mm x 50mm. But when you again add the stroke the measurement will increase. So its an issue in Illustrator

By @Moiz Hussain

Turn off "Use Preview Bounds" in the preferences or the transform panel.

M

Moiz Hussain

Participant

Thank you very much

G

GabrielHAZE

Participant

It's happening to me as well.

In fact, just now I have an artboard open in inches.

I drew a square, locked its proportions and told itto make it 100 cm (because it always converted it for you).

Low and behold, Illustrator thought it equaled 37".

So I changed the rulers to CM, drew a 100 x100 cm square and then it knew it was 39.97".

The other day I fought with the program because it would NOT allow me to keep boxes the size I wanted.

If I typed 5" x 6" it would convert the box to 4.897" x 5.696" etc.

• I tried unchecking scaling corners, strokes ... etc.

• I tried resetting preferences etc.

Truth is, I'm going to have to start sending Adobe bills for labels we buy if they playing these stupid games because labels at the size I work with, those micro measurements are a LOT!

See video.

adobe_measurements-mess-up.zip

Anshul_Saini

Community Manager

Hi @GabrielHAZE,

Sorry to hear about the issue you are facing. I checked your video, and it seems the "scale width & height proportionally" is checked.

Disable it and enter the dimensions & check if you are getting perfect values as you intended or not.

I will be looking forward to your response.

Thanks & Regards,

Anshul Saini

SIMS SOLUTIONS

Participating Frequently

Did this work as I am having the same problem. I simply want a square. This should not be complicated -either 4X4, 5x5. Please advise, I do not have time for such errors

T

Test Screen Name

Legend

Illustrator is not going to change its calculations to use the selected unit. That is for display purposes. So the units you type will be converted to whatever Illustrator uses internally. This is not a matter of deliberate rounding, but a consequence of that choice. The alternative would be worse.

We don't know what Illustrator uses to calculate, but let's imagine it is the same as older versions of Acrobat, which was a type called "ASFixed". In this we store numbers as 1/65536 points. Whole numbers of points and inches would be stored exactly. This is just an exercise.

In this, 50mm is stored as 50 * 25.4 / 72 * 65536. This is approximately 1,155,982.222222222 so it would have to be stored as 1,155,982 or 1,155,983.

1,155,982 converted back to mm is approx 49.99999038816437 mm.

1,155,983 converted back to mm is approx 50.0000336414247 mm.

So rounding will happen. People agonize over seeing small changes far after the decimal point without considering how small the difference actually is. Sometimes they demand the mathematically impossible too.

twinbrushAuthor

Inspiring

I know the alteration is minuscule, and I have no idea why or how the calculation is needed...nor do I need to I suppose. It just seems necessary to me to do additional calculations, units of measurements should be the unit of measurement...but hey, I'm not a programmer

Ton Frederiks

Community Expert

Do you have a (tiny) stroke around the rectangle?

twinbrushAuthor

Inspiring

Nope, no stroke, just a solid fill of 0 0 0 100

Jacob Bugge

Community Expert

Rian,

Is it also happening if the Artboard and rectangle have the corners at whole X and Y values (especially 0,0)?

0.003 mm ~ 0.001 pt, so a rather small deviation, more visually than practically disturbing, less than the bulging of a 10 pt circle.

twinbrushAuthor

Inspiring

Yea the artboard x and y are 0 whole values. Its definitely such a small deviation that I doubt it would ever be noticed...just a pet peeve I guess, if as it seems, its just an internal calculation made by Illustrator