Problems subtracting one curve from another

[HumblePie]

Hi all,

I am a very new user to Affinity Desktop so I have been trying to watch tutorials and troll the forums to help me get up to speed with some common tasks. As a bit of a learning process, I wanted to do some simple steps which consisted of subtracting one shape (curve) from another (curve). I found that in doing so, the cut out only appears to work if a segment is touching the outline of the base shape. If I repeat the process with an ellipse or a rectangle the subtraction works as expected...whether or not the subtracted shape is touching the outline of the base shape or is fully contained within it.

I have included some screenshots to help illustrate the issue I am seeing. 

Info for each picture

1. shape removal 0 - This shows one curve (the star) that I want to remove on top of the base curve
2. shape removal 1 - When using the Subtract option, the removal does not appear to work like I would expect.
3. shape removal 2 - If I move the star curve shape to touch the outline of the base curve and repeat the subtraction, the part that was touching the outline is, in fact, subtracted. The other segments are not.
4. shape removal 3 - This image just shows all the different shape types that I was testing out 

I've also attached my afdesign file in case that helps with any necessary troubleshooting.

Any info, guidance, feedback, etc. is much appreciated.

Thanks.

shape removal test.afdesign

[firstdefence]

This file locks my Affinity Designer up and I have to force close it.

Try this file: test file.afdesign

 

[lepr]

7 hours ago, HumblePie said:

Hi all,

I am a very new user to Affinity Desktop so I have been trying to watch tutorials and troll the forums to help me get up to speed with some common tasks. As a bit of a learning process, I wanted to do some simple steps which consisted of subtracting one shape (curve) from another (curve). I found that in doing so, the cut out only appears to work if a segment is touching the outline of the base shape. If I repeat the process with an ellipse or a rectangle the subtraction works as expected...whether or not the subtracted shape is touching the outline of the base shape or is fully contained within it.

I have included some screenshots to help illustrate the issue I am seeing. 

Info for each picture

1. shape removal 0 - This shows one curve (the star) that I want to remove on top of the base curve
2. shape removal 1 - When using the Subtract option, the removal does not appear to work like I would expect.
3. shape removal 2 - If I move the star curve shape to touch the outline of the base curve and repeat the subtraction, the part that was touching the outline is, in fact, subtracted. The other segments are not.
4. shape removal 3 - This image just shows all the different shape types that I was testing out 

I've also attached my afdesign file in case that helps with any necessary troubleshooting.

Any info, guidance, feedback, etc. is much appreciated.

Thanks.

shape removal test.afdesign 35.5 kB · 4 downloads

The issue is that your lowest shape (the blue  thing)  in the Boolean operation has winding fill mode and so the result has winding fill mode. With winding fill mode, the relative directions (clockwise or anticlockwise) of paths determine how a shape is filled. The other fill mode, alternate, is not dependent on path direction and it is the default fill mode in Affinity apps, so perhaps you imported your shapes from some file created by another app if you didn't deliberately change their mode to winding in Affinity

After performing the subtract, ensure the result is selected then do Layer > Fill Mode > Alternate.

Alternatively, set the lowest object to alternate before doing the subtract so the result will have alternate fill mode.

[h_d]

Alternatively, run Geometry - Smooth Curves click the Node tool and then click Smooth Curve in the context menu bar on both the 'flower' and the 'cloud', then the subtraction operation will work correctly. Presumably this also rectifies the fill issues identified by @anon2

EDIT: Please disregard my answer - posted in error. H

 

[Move Along People]

-

[h_d]

2 hours ago, haakoo said:

do you mean the smooth curve option in the nodetool?

Apologies, yes I do.

I've edited my original post.

[HumblePie]

7 hours ago, anon2 said:

The issue is that your lowest shape (the blue  thing)  in the Boolean operation has winding fill mode and so the result has winding fill mode. With winding fill mode, the relative directions (clockwise or anticlockwise) of paths determine how a shape is filled. The other fill mode, alternate, is not dependent on path direction and it is the default fill mode in Affinity apps, so perhaps you imported your shapes from some file created by another app if you didn't deliberately change their mode to winding in Affinity

After performing the subtract, ensure the result is selected then do Layer > Fill Mode > Alternate.

Alternatively, set the lowest object to alternate before doing the subtract so the result will have alternate fill mode.

Wow. This would have taken me a very long time to figure this out. Thank you for the information. This resolved the issue I was seeing. 

And, to add to the information, you were 100% correct. To make this task faster, I brought in the curve shapes from another file and just pasted them in. I was not aware of the fill type so this is something I'll have to do a bit of reading on. Thanks again for the information. Very much appreciated.

[HumblePie]

7 hours ago, h_d said:

Alternatively, run Geometry - Smooth Curves click the Node tool and then click Smooth Curve in the context menu bar on both the 'flower' and the 'cloud', then the subtraction operation will work correctly. Presumably this also rectifies the fill issues identified by @anon2

 

@h_d, I'll need to keep playing with this option. I did a few really quick attempts this morning but it did not seem to resolve the issue. Unfortunately, I didn't have much time so will give this another go later this evening. Thanks for the information. I appreciate the assistance.

[lepr]

51 minutes ago, HumblePie said:

@h_d, I'll need to keep playing with this option. I did a few really quick attempts this morning but it did not seem to resolve the issue. Unfortunately, I didn't have much time so will give this another go later this evening. Thanks for the information. I appreciate the assistance.

Smooth won't help, and it will distort your shapes.

[h_d]

I think I must have still been asleep this morning when I posted my original answer. TBH I'm not quite sure now the precise steps I went through, so sorry @HumblePie but I may have led you on a wild goose chase. I'll leave my posts in place but edit them to reflect this.

[HumblePie]

20 hours ago, h_d said:

I think I must have still been asleep this morning when I posted my original answer. TBH I'm not quite sure now the precise steps I went through, so sorry @HumblePie but I may have led you on a wild goose chase. I'll leave my posts in place but edit them to reflect this.

Not a problem at all.   I appreciate the time and effort. Thanks!

[appaulmac]

On 11/5/2020 at 3:50 AM, ,,, said:

The issue is that your lowest shape (the blue  thing)  in the Boolean operation has winding fill mode and so the result has winding fill mode. With winding fill mode, the relative directions (clockwise or anticlockwise) of paths determine how a shape is filled. The other fill mode, alternate, is not dependent on path direction and it is the default fill mode in Affinity apps, so perhaps you imported your shapes from some file created by another app if you didn't deliberately change their mode to winding in Affinity

After performing the subtract, ensure the result is selected then do Layer > Fill Mode > Alternate.

Alternatively, set the lowest object to alternate before doing the subtract so the result will have alternate fill mode.

Why do I ALWAYS forget this!!! After years of working in Illustrator and now Designer....