Need help with Boolean Operations

[Chris Sokolov]

Hi everyone,

I'm creating this topic because of an issue I have with Affinity Designer.

Let me show you an example on the last project I had to work on.

I have two circles who are curves, and I want the part of the smaller circle who is outside the bigger to disappear.

.

Here's how I tried to do that :

1/ I duplicate them (because I'll need them again later), hide the first ones and and divide the new ones with a boolean operation.

 

2/ I delete the part that I don't need.

3/ And finally, I combine them with the "Add" boolean oparation.

 

And, there is my problem. I still have a small space between them, we can see it a little on the last screenshot, but let me show it to you with a zoom.

How can I avoid this ? The spaces are here, they are real and can be seen at almost every level of zoom, even more if I apply a gradient on it (bad luck, this logo is with a gradient lol).

A last screenshot that will maybe help you help me :

 

As you can see, the two "levers" that allow me to change the curve are not exactly at the same position, I think that my problem will be solved if they were, but why aren't they ?

Thanks a lot to those who will at last try to help me, that's a problem who completely prevents me to work on logo projects with Affinity Designer.

Chris

[John Rostron]

Are these lines still there if you deselect the curves?

John

[Dan C]

Hi Chris Sokolov

Thanks for your screenshots, I can see your objects aren't pixel aligned in your document (ie there aren't located on whole pixels)

Please create the design with the X & Y positions for each object on whole pixels, as shown in my below screenshots -

Now follow your divide, delete and add workflow. You should find at 100% zoom these lines are no longer visible -

I hope this helps!

[Chris Sokolov]

Hello John,

What exactly do you mean by deselecting the curves ?
 

Hello Dan,

On my screenshots, they were not in full pixels only when selected together, each object selected separately is on full pixels.

But ok, I got it, and in this case, what if I need to make a logo with my own custom grid, without regarding the pixels, say for example that I need the top left corner of my little circle to be at the exact center of the bigger circle, this is not about pixels, right ? How am I supposed to do then ?

Thank you for you time by the way

EDIT : I just tried again, and this time I was regarding to the pixels, but the prooblem is still here

Edited October 28, 2019 by Chris Sokolov

[firstdefence]

Chris before you add them together, you see the squarish shapes, move the edges outwards slightly, see video attached.

[Chris Sokolov]

Hello firstdefence,

Thank you for the video, that's actually how I did it, but it feels more like a "hack" than a "clean" way to do it, maybe I'm wrong ?

The only thing with that method is the points that have nothing to do there, can I be sure that if I delete them my circle will stay a perfect cicrcle ?

I talk here about the two lowest of the screen, but the one in red at the top left has nothing to do there too.

Thanks again !

[dutchshader]

i would not use divide in this case, just draw a shape around the part you want to delete,

select both and subtract

select both add, the result has no extra nodes:

 

[Chris Sokolov]

Hello dutchshader,

That seems to be the best way to do it, thank you

[John Rostron]

6 hours ago, Chris Sokolov said:

What exactly do you mean by deselecting the curves ?

I mean that none of the curve components are selected. That is none of them are highlighted in the Layers panel. Just click anywhere outside your curves. I'm sure those lines are just Designer's indication of the object boundary which only show when your curve is selected.

[Chris Sokolov]

30 minutes ago, John Rostron said:

I mean that none of the curve components are selected. That is none of them are highlighted in the Layers panel. Just click anywhere outside your curves. I'm sure those lines are just Designer's indication of the object boundary which only show when your curve is selected.

Ah, got it, but no, I can confirm, these lines are real.

[Vicente Bermúdez]

Hello Chris. Let me show you another way to do what you want in a precise and fast way. And you will not have any node left or curves open.

 

[R C-R]

On 10/27/2019 at 11:12 AM, Chris Sokolov said:

I have two circles who are curves, and I want the part of the smaller circle who is outside the bigger to disappear.

Why not just clip the smaller circle into the larger one? Everything remains editable so you could move the smaller circle around, change the stroke width of either or both circles, change the color of one or the other, etc.

[Joachim_L]

Damn, a few seconds to slow.

Just my thought on how to do this, the solution from Vicente is cool anyway:

1. Create the circles.

2. Drag the smaller circle into the bigger circle.

[PixelPest]

That´s why we need a parametric circle object:

[firstdefence]

Bravo @Vicente Bermúdez Simplicity itself.

[R C-R]

34 minutes ago, firstdefence said:

Simplicity itself.

What could be simpler than clipping? It is just one step to nest the smaller circle (or whatever) into the larger one.

[firstdefence]

1 hour ago, R C-R said:

What could be simpler than clipping? It is just one step to nest the smaller circle (or whatever) into the larger one.

Clipping doesn't work on Donut shapes.

[R C-R]

2 hours ago, firstdefence said:

Clipping doesn't work on Donut shapes.

True, but there is no reason to use donut shapes to get the result that was asked for. A pair of stroked & unfilled ellipses constrained to circles does that & remain 'perfect' (to the limits of the bezier-based circles Affinity uses). It would take a bit of tweaking to match stroke gradients if that was desired but it is not hard to do that.

That way, everything remains editable & the node count is much lower.

[dutchshader]

17 minutes ago, R C-R said:

True, but there is no reason to use donut shapes to get the result that was asked for. A pair of stroked & unfilled ellipses constrained to circles does that & remain 'perfect' (to the limits of the bezier-based circles Affinity uses). It would take a bit of tweaking to match stroke gradients if that was desired but it is not hard to do that.

That way, everything remains editable & the node count is much lower.

have you tried exporting as svg, and than open the svg in designer?

[R C-R]

17 minutes ago, dutchshader said:

have you tried exporting as svg, and than open the svg in designer?

Have you tried using the donuts method with a smaller radius donut as the second shape, as in the OP's example? Doing that & maintaining the same thickness of both shapes is difficult to do precisely because the hole radius is adjustable by percent. Or have you tried changing the amount of or the position of the smaller circle that is hidden after the boolean operation?

My point not to find fault with the donuts method, which is indeed clever. It is just that all the OP said was wanted was for the part of the smaller circle outside the bigger one to disappear. There are several ways to do that. Some are better than others, but it all depends on the desired end result.