How to change drawing scale (µm, km, 2:1, 1:5, 10:1, ...)?

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theozh
Posts: 437
Joined: Fri Mar 23, 2012 6:30 pm

How to change drawing scale (µm, km, 2:1, 1:5, 10:1, ...)?

Postby theozh » Thu Oct 30, 2014 12:15 am

I'm pretty sure that I am not the first one asking this, but with the forum search I couldn't find any satisfying answer.

I would like to fit a drawing e.g. on a A4 page but still would like to work with the real numbers and units.
Inkscape allows to work e.g. in mm, cm and m. However, not in µm (Mikrometer) or km.
Desirable would also be some arbitrary scales like 10:1, 2:1, 1:5, etc.
But I haven't found a feature to change the drawing scale. Is there such a feature? If yes, where? If not, why not? ;-)

There was an earlier post asking about how to drawing in µm, however, without practical suggestions. Scaling the objects in the drawing back and forth or post processing of the .svg file is not a practical way for me.
Are there any new features or solutions since then?
Thanks for suggestions!

hulf2012
Posts: 716
Joined: Sat Nov 24, 2012 12:37 pm

Re: How to change drawing scale (µm, km, 2:1, 1:5, 10:1, ...

Postby hulf2012 » Thu Oct 30, 2014 3:32 am

Hello:
I think that learning about Transformations could help in your objective.

http://tavmjong.free.fr/INKSCAPE/MANUAL ... forms.html

This subject about scales is something to be asked directly with the developers
You can begin here:
https://inkscape.org/en/contribute/report-bugs/

On the other hand, maybe I don't understand what you want. Perhaps if you can share an example of what you want, or where is neccesary to have a document with different scales or measure units.

But let me say that:
1.- The SVG format is not (yet) a CAD format.
2.- To have a document capable of renderize drawings from micrometers to kilometers, will consume a lot of resources of the computer, in my opinion.

Greetings
If you have problems:
1.- Post a sample (or samples) of your file please.
2.- Please check here:
http://tavmjong.free.fr/INKSCAPE/MANUAL/html/index.html
3.- If you manage to solve your problem, please post here your solution.

Lazur
Posts: 4694
Joined: Tue Jun 14, 2016 10:38 am

Re: How to change drawing scale (µm, km, 2:1, 1:5, 10:1, ...

Postby Lazur » Thu Oct 30, 2014 4:05 am

Hi.

  • Support for real world document and page size units, e.g. millimeters

0.91 release notes

Couldn't find it in a pre release, though the new version is currently in the freeze stage and will be out in a few months -around the end of the year.

As in the other post you have linked, inkscape is capable for 10^ -32 accuracy in storing data, however the inaccuracy appears much larger during processing.
For example, boolean operations can result in 0,2 px differences.
Thus, as in general, drawing larger and scaling down after can improve precision -mistakes scale down too that way.
Mandatory if you need a tiny but precise image.

On the scale suggestion, I can't get it. What's the object's size in real life units, should measure scaled matching the set numbers, on screen?
Each screen has a different resolution, and, the pixels displayed are much larger than what could make it precise.

theozh
Posts: 437
Joined: Fri Mar 23, 2012 6:30 pm

Re: How to change drawing scale (µm, km, 2:1, 1:5, 10:1, ...

Postby theozh » Thu Oct 30, 2014 5:55 am

Thank you for your comments.
1.- The SVG format is not (yet) a CAD format.

OK, then I am maybe misusing Inkscape as a CAD-tool.
The application is simple. Drawing e.g. lithography masks in microtechnology. Its not very comfortable and readable if you have to type in always 0.005 or 0.1 (mm) instead of 5 or 100 (µm). Maybe I should use another program. Too bad, because I like the object and path functions of Inkscape.

2.- To have a document capable of renderize drawings from micrometers to kilometers, will consume a lot of resources of the computer, in my opinion.


I didn't mean that there is a need for having µm and km in the same document. But either or would be good, i.e. the one or the other as base drawing unit.
About the scaling: You may want to sketch something (either in um or km) and you want to send it to somebody as a PDF which can simply be printed out (e.g. on a A4 or A3 sheet). So, why drawing it in 1:1, or scaling each single object already while creating and then afterwards scaling all objects down or up so they roughly fit the A4 (A3) page? Why not drawing it directly in 1000:1 or 100:1 or 1:10 or others...?
Win7/64, Inkscape 0.92.2

hulf2012
Posts: 716
Joined: Sat Nov 24, 2012 12:37 pm

Re: How to change drawing scale (µm, km, 2:1, 1:5, 10:1, ...

Postby hulf2012 » Thu Oct 30, 2014 7:24 am

Hello
I forgot to say that SVG can be exported to DXF. But I think it's not a 100% exact exportation. There is also an extension for exporting to Gcode, for using with CNC machines. I don't know what kind of data format use the lithographic masks.

Sorry I don't get it about that scaling feature that you want. I pointed to that transformation pages of the Inkscape Guide because there it speaks about the Transforms dialog (Shift + Ctrl + M) which allows you numerically scale (and move and rotate) an object or a group of objects.

In AutoCAD there are paper space or drawing space.If I'm not wrong, in the paper space you can put several "views" of the drawing with diferent scales each. Inkscape doesn't have this concept. I don't know if in the SVG allows that concept.
If you have problems:
1.- Post a sample (or samples) of your file please.
2.- Please check here:
http://tavmjong.free.fr/INKSCAPE/MANUAL/html/index.html
3.- If you manage to solve your problem, please post here your solution.

Lazur
Posts: 4694
Joined: Tue Jun 14, 2016 10:38 am

Re: How to change drawing scale (µm, km, 2:1, 1:5, 10:1, ...

Postby Lazur » Thu Oct 30, 2014 7:50 am

1 µm=0,001 mm=0,00003937 inch=0,0035433 px;
while inaccuracy can be at 0,1 px.
More than that, you can zoom in only to 25600%, which would make the 1 µm displayed at about 0,907 px, when zoomed in to the max.
A scale of 10000:1 or 1000:1 would be good for that.

Didn't investigate much with km sized drawing, but it's an overkill to the current renderer.
The 1% zoom level would make 1 km appear 3543307 pixels, while it seems there is a 1000000 pixel size limit at the input field in the current stabile for object widths (~282 m).


No need to scale each object individually, maybe it's even possible to transform just the layer you are working on after.
Printing it out as on an A4 sheet, is commonly done at 600 dpi to the max. Which means 23,62 dpmm, a dot being 0,042333 mm=42,333 µm.
Simply you cannot get to the details even if preserved right in the pdf.
Even art printers are capable 2400 dpi the most, with a dot being 10,583 µm.
That amount of detail would need special equipment.


Staying at the cad-like features, it's more drafting related as the graphical symbols used differ at different scales.
Should I mention printing the plans? I have seen cad made pdf-s and they look plain horrible in general in my opinion.
It was on my mind when starting this project.

theozh
Posts: 437
Joined: Fri Mar 23, 2012 6:30 pm

Re: How to change drawing scale (µm, km, 2:1, 1:5, 10:1, ...

Postby theozh » Thu Oct 30, 2014 7:06 pm

Typically for litho mask drawings people are using Gerber or DXF or other formats. However, the DXF export from InkScape does not really work. I had very strange results when importing these DXF files into a CAD-Software.
Another example, geographical maps have scales of 1:25000 or 1:50000 or others.
I simply want to type in the dimensions in InkScape as real world dimensions, e.g. 2.5km on a map or 2.5um on a lithomask but the drawing should still be printed on a A4 or A3 page. And I do not want to scale the whole drawing afterwards. If I need to correct anything I have to scale it back and forth again and again.

Generally speaking, there is a number and a unit. I do not know how numbers and units are stored in InkScape (maybe just in pixels?). But I would like to simply draw objects with dimension 2.5 but in one documents it's 2.5um and in the other it's 2.5km.

@hulf2012
Well, paper space and drawing space might describe the "wanted feature".

@Lazur URH
Yes, for photolitho masks some companies have that special equipment which exposes films with a resolution of about 25'000 dpi or higher.
Win7/64, Inkscape 0.92.2

rowan.bradley
Posts: 14
Joined: Sat Nov 29, 2014 10:33 pm

Re: How to change drawing scale (µm, km, 2:1, 1:5, 10:1, ...

Postby rowan.bradley » Sat Nov 29, 2014 10:47 pm

Was this question fully answered? I'm new to Inkscape, but I too want to be able to draw drawings to scale. For example, an architectural drawing may be 1:50 or 1:100 or 1:200. I would like to be able to enter positions and distances in real world dimensions, but for them to be correctly scaled on the drawing. I would like to be able to add dimensions on the drawing, and for the numbers to automatically show in real world distances. Like the previous poster I think that scaling the drawing afterwards is hopelessly inefficient, if a drawing goes through many stages of refinement. CorelDraw has this feature. Adobe Illustrator does not. To me it seems an essential feature for a good vector drawing package. Does this exist within Inkscape? If not, could it feasibly be added as an add-on?

Thanks - Rowan

hulf2012
Posts: 716
Joined: Sat Nov 24, 2012 12:37 pm

Re: How to change drawing scale (µm, km, 2:1, 1:5, 10:1, ...

Postby hulf2012 » Sun Nov 30, 2014 12:30 am

Hello,
I will try to explain me: This kind of questions is kind of "Does it have a BUTTON like in [AUTOCAD/ corel draw / adobe illustrator / xara extreme / photoshop / Paint / Gimp etc, etc]?" cliché question.

And I feel that I never win on this kind of questions.

Most of the times, Inkscape doesn't have anything similar. So the answer quite often is NO.

However, Inkscape have other features that can help to obtain the same results... but it may take some more time,or it will depend of other programs, or it will mean to Learn another method than the used in another software. (*)

Tipically, the answer to this explanation is: "sorry It doesn't works for me. I will search for another software".


Please, RTFM!
the Inkscape Guide

If you get stucked in some step of your design, ask for help.

(*) I don't know for sure, but in graphic design world there is a norm or standard about methods or proccess to make a design?.
Sorry for the bad english, I'm still learning it.
If you have problems:
1.- Post a sample (or samples) of your file please.
2.- Please check here:
http://tavmjong.free.fr/INKSCAPE/MANUAL/html/index.html
3.- If you manage to solve your problem, please post here your solution.

Lazur
Posts: 4694
Joined: Tue Jun 14, 2016 10:38 am

Re: How to change drawing scale (µm, km, 2:1, 1:5, 10:1, ...

Postby Lazur » Sun Nov 30, 2014 6:29 am

Off topic:
hulf2012 wrote:I don't know for sure, but in graphic design world there is a norm or standard about methods or proccess to make a design?


It's mostly practice. Standards are made in the name to make designs -and plans- self-explanatory. Which is based on practice too.
Around here, iso standards are used in general, and the technical field has a strong german root.

But, you can find some gems on the internet, like how designing and drafting was done a century ago.
Here is a collection of books mostly from the U.S..

Some examples:
drafting room methods (1918)
essentials for drafting (1919)
systems and practice of the drafting room (1910s)
machine design (1899)
architectural drafting (1913)
structural drafting (1920)

hulf2012
Posts: 716
Joined: Sat Nov 24, 2012 12:37 pm

Re: How to change drawing scale (µm, km, 2:1, 1:5, 10:1, ...

Postby hulf2012 » Mon Dec 01, 2014 1:58 am

Thanks for the info Lazur URH.
I took a look to the drafting room methods book, and I think it show things that still are valid, like the symbology.

More to say:
I don't think that there is a method, for example, for scaling a drawing, like "press this button, and then this other, and then write that in this textbox". So things like "essential features" that any design software must have,... well, I disagree there.

Anyway, if adding a button, or a dialog box, can shorten the drawing time then it could be a good feature.
If you have problems:
1.- Post a sample (or samples) of your file please.
2.- Please check here:
http://tavmjong.free.fr/INKSCAPE/MANUAL/html/index.html
3.- If you manage to solve your problem, please post here your solution.


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