Easiest way to attach objects each other?

[ashf]

What's the easiest way to attach multiple objects each other precisely without a gap?
I'm using the point transform tool and the snap to object geometry option, but it's often not precise or difficult.

Attached picture is just an example, not exactly what I want. the situation is different each time.

[Petar Petrenko]

Why don't you explore Snapping tool (on the toolbar) in depth? There are plenty of options and I believe you will find the right one.

[Old Bruce]

As far as I can tell there is no "edge detection" snapping.

On 11/11/2022 at 2:24 PM, ashf said:

What's the easiest way to attach multiple objects each other precisely without a gap?

 

[NotMyFault]

In Designer, you can snap a node using the node tool to the curve of another layer. Just select all nodes of one object, then click-drag one node and drag to the edge of other objects.

This does not help to snap one object to more than a second object or 2 node / edge pairs in parallel.

It can help adding nodes at intended contact points.

Another trick is using helper objects of almost invisible size.

But there is no general solution covering all possible situations.

If you can live with accuracy of <=1px, using pixel mode and channels adjustment can help to align shapes manually so that the gap becomes invisible.

 

[ashf]

Yeah, actually this is not possible because of precision of the Bezier If I need high accuracy on that, according to what I found.
This requires calculation of the "common tangents" and it seems that some CAD software have it. (Not even Illustrator can.)
Not sure it can be implemented in Affinity.

 

[loukash]

17 hours ago, NotMyFault said:

Another trick is using helper objects

15 hours ago, ashf said:

This requires calculation of the "common tangents"

I just looked up the math of an ellipse (hey, it's been over 40 years since my last geometry lessons!) on mathopenref.com/ellipsefoci.html and mathopenref.com/ellipsetangent.html

So what we need here is to construct "helper tangents" for each object. That's easy with a circle, needs a bit more math with an ellipse to find its focus points: 
F = √(j^2 − n^2)
See also the source code of the ellipsetangent.html page on how the interactive JS applet works. (I'm no JS programmer so don't ask me…)
When you have your tangents, you only have to turn on appropriate object and node snapping options.

~~~

Alternatively, keep in mind that you can zoom in as close as more than whopping 300000000 % (!) and you'll still see the curves to align them so that they touch. Set the blend modes to Multiply to see when they overlap. Use the Transform Origin snapping to object geometry to align multiple ellipses. In the end you can add an invisible shape with nodes at the ellipses centres and at the touching points, so that you don't have to search for them again:

[loukash]

11 minutes ago, loukash said:

construct "helper tangents" for each object.
[…]
zoom in

Or alternatively, get VectorStyler:

That would be exactly one of those cases what I have bought VS for (while it was on sale last month).
Then just copy the shapes back to Affinity. Works fine.