Inconstancy between Rulers, Dimensions and Grid settings

Bill.Thomas · November 19, 2023, 12:35pm

Draw version 7.5
Page set to A4 landscape. Dimension units = mm. Scale = 1:1. Grid resolution X = 5mm, Y= 5mm.
Top “Ruler” full scale = 297mm. Correct for A4.

Draw an object (eg rectangle) with length = 40mm. Add a dimension to this which comes up as 40mm.
Verify this dimension from the top “Ruler” scale. OK.
Verify this dimension from “Grid”. Occupies 8 grid lines = 8 x 5mm = 40mm. OK

Change drawing scale to 2:1.
Top “Ruler” full scale now = 148mm. OK
Dimension on the drawn object now = 20mm. This agrees with the new “Ruler”. OK
But the object still occupies 8 grid lines and the “Grid” resolution is still X = 5mm, Y = 5mm so the object dimension must still be 40mm.

I think the grid resolution should have changed as I changed the drawing scale.
Either I don’t understand something or there is bug here. Any explanation would be welcome.
My work around is to turn off the grid and rely only on the rulers.

Bill

Zizi64 · November 19, 2023, 12:41pm

I think, the grid values are related to the Page size, what will not be changed when you change the Drawing ratio. The changed object size values are “virtual” values on the same page size.
Of course you can change the grid size manually.

cwolan · November 19, 2023, 7:49pm

LibreOffice 7.5 Draw User Guide, p. 296

Bill.Thomas · November 20, 2023, 10:51am

Thanks for the responses. I now understand that the grid is only an aid to the page. It will define the size of the printed object only.
However this is not immediately obvious. It is very convenient to use the grid as a guide to placing and sizing objects and this works very well if the drawing scale is 1:1 but quickly leads to great confusion if you change the drawing scale.
Maybe there needs to be a warning note in the dialog box where you set the grid parameters. If you think something is wrong and you go and check the grid resolution you would see a warning note reminding you that it only applies to the page and printing size.
PS. I am enjoying escaping from MS office and Visio. A donation will be a small price to pay.

Bill