Snap guides to ruler?

[AllAppsUser]

I'm trying to snap a guide to exactly 30 cm using the ruler.

Looking in the snap settings, nothing suggests itself as a means to do so

Q: Is it possible to set snap settings so placing guides will snap to the ruler when visible?

Q: If not, how do you approach it?

[GarryP]

I don’t think the rulers have any contribution to snapping.
If you want a guide at a precise location then you can add one using the Guides Manager.
Having said that, it might be nice to be able to snap the guides to the ruler major divisions when a guide is being dragged out.

[loukash]

3 hours ago, ProDesigner said:

how do you approach it?

Snap to Grid by using e.g. the "1cm square" preset. Neither the ruler nor the grid need to be visible.

[v_kyr]

Another workaround is, to create the custom sized ruler and scaling you need. Import the generated SVG into the Affinity product you use, align it accordingly to your document size, lock it, and then place/align your objects according to that custom ruler.

[h_d]

View - Snapping Manager (sounds nasty), uncheck "Only snap to visible objects":

No need for a specific grid setting.

Depending on screen tolerance and zoom you'll then be able to snap to the rulers. A high screen tolerance will mean less chance of snapping to the ruler units, especially at zoomed out views. I tried setting mine to 45, and snapping to the rulers didn't happen at around 25% zoom.

[loukash]

36 minutes ago, h_d said:

View - Snapping Manager

Yes, that's what I meant by "Snap to Grid" which is the only checkbox needed for this kind of "snapping by ruler division".
If the Grid Manager is set to Automatic, snapping is dependable by the zoom factor. Hence a specific grid preset may be useful to avoid too excessive snapping.

BUT:

This all works only as long as the ruler zero point matches the grid. If the zero point is elsewhere – off the grid – there's no way to snap to ruler whatsoever.

In other words, it looks to me like a feature request topic:

Add "Snap To Ruler" to the Snapping Manager

[Old Bruce]

19 minutes ago, loukash said:

This all works only as long as the ruler zero point matches the grid. If the zero point is elsewhere – off the grid – there's no way to snap to ruler whatsoever.

 

You can get your Grid Axis to snap to the Ruler origin by enabling Snap to .... Spread 

Going the other way is as easy as turning on Snap to Grid before moving the ruler origin.

If you must have the Grid and the Ruler mismatched then no, there is no way to snap to the ruler at present.

[loukash]

Just now, Old Bruce said:

You can get your Grid Axis to snap to the Ruler origin by enabling Snap to .... Spread 

Of course.

1 minute ago, Old Bruce said:

If you must have the Grid and the Ruler mismatched then no, there is no way to snap to the ruler at present.

That's what I meant, thanks for clarifying.

[AllAppsUser]

Thank you everyone for contributing. Really interesting. I'm learning all the way.

Basically, from what I've read here, and with my own experimenting informed by what I've read here, the rulers (as @GarryP indicated) only labels the grid (when they happen to align). The rulers do not contribute to snapping at all.

@h_d's key suggestion of Unticking "Only snap to visible" led me to gain an insight to this. Even then you need 'Snap to Grid' on because that what it's doing.

Basically there are too many levers to pull here in my view:

• Screen tolerance
• Grid divisions (settings)
• Zoom

Plus.. an ever present danger of misaligned rulers and grid, even by a fraction of a millimetre which could be dangerous for precise work (if rarely). Good heads-up there by @Old Bruce on ways to sort it.

I've mucked about with it all, and sort-of achieved what I needed. Here's my recipe:

Small enough grid divisions (20) + minimum screen tolerance (3) + grid & ruler aligned = workable ruler-esque snapping zoomed out.

Doesn't feel very satisfactory to me. I agree with @loukash, this is definitely a feature request.
For quick and accurate guide placement, why the heck ignore the snapping possibilities of the ruler?

Thank you everyone - great team effort! Really helpful of you all, thanks for taking the time. Appreciated.

----------------

Fascinating creative thinking by @v_kyr, btw... Serif should check out the ruler Apple have introduced to Mark-up, because this is what @v_kyr has pointed the way to. What a useful on-the-fly tool. I recommend Serif look at it as a built-in feature.

[loukash]

1 minute ago, ProDesigner said:

For quick and accurate guide placement, why the heck ignore the snapping possibilities of the ruler?

Option-drag a guide already ignores snapping.
So why not e.g. Shift-drag or Command-drag for Snap To Ruler Ticks?

[v_kyr]

Forgotten to tell about some placable visual help school rulers, I had once made some as assets which are already 30 cm long.

• Measuring and rulers

Those can be placed and locked as sort of guides then.