Need a little help with the subtract function

[alibali]

Hi,

 

Apologies if this is already explained somewhere but I have searched other posts and help to no avail.

 

New to Affinity Designer and not that much experience with vectors in general so hope this isn't too dumb a question but I can't understand why the subtract function is cutting my two shapes in a particular way. I have attached a file showing the two shapes and what happens when I subtract the crescent shape from the half circle - why does the new shape still contain the small line at the end of the half crescent and half moon?! I was expecting it to negatively cut away all that space to effectively leave the shape like my example C (it took me forever to work out how to just cut away that small section as I couldn't get the break curves function to work either for a bit ... think I have a steep learning curve ahead :-)).

 

Would be very grateful if anyone could take a moment out their day to explain the above to me.

 

 

Many thanks,

 

Ali

x

 

Subtract problem.afdesign

[toltec]

It is because of the way the half moon is made. Don't know how you did it ?

 

If you select it with the node tool, you can see the double nodes at the end of the straight line.

 

 

 

 

 

 

All I did was drag the points so they aligned, then it worked.

 

I'm not 100% sure why 

[dutchshader]

i did allmost the same thing, moved the sharp nodes away from the smooth nodes.

and this way it allso works like it should.

looks like a bug i guess

[alibali]

oh, thank you so much for explaining that guys. Thought I was going mad not understanding how the function worked!

 

I made the half circle by subtracting a rectangle from a circle but didn't notice the resultant nodes were close to each other so will watch out for that happening in future. Am following a tutorial with a file originally created in Illustrator (that is the program the tutor is using but he didn't seem to have any issue cutting the shape). Do you think this is indeed a bug and should I be reporting it somewhere then or is this just inexperience on my part and I should be more careful how I cut in future? 

 

Thanks again for solving this so quick, can get back to my tutorial now x

[toltec]

24 minutes ago, dutchshader said:

i did allmost the same thing, moved the sharp nodes away from the smooth nodes.

and this way it allso works like it should.

looks like a bug i guess

 

Your shape seems to have gained weight. Too much whipped cream I guess 

 

[dutchshader]

Too much ........

 

[Alfred]

43 minutes ago, alibali said:

I made the half circle by subtracting a rectangle from a circle

 

Instead of subtracting a rectangle from the circle, select the circle with the Node Tool and press the 'Convert to Pie' button on the Context toolbar, after which you can adjust the Start angle to whatever you want and then set the Total angle to 180° to give you a semicircle. A shorter route to the same end result would be to start with the Pie Tool instead of the Ellipse Tool, allowing you to omit the conversion step.

 

[alibali]

Fab Alfred, thanks for pointing those two tools out - so much to learn in this software, it is amazing and the help and support from the community is top-notch 

[JimmyJack]

3 hours ago, alibali said:

Do you think this is indeed a bug and should I be reporting it somewhere then or is this just inexperience on my part and I should be more careful how I cut in future? 

 

 

 

I didn't change or move any nodes relative to each other on the "semi-circle" shape.

I just rotated the whole thing so the straight part was past horizontal (or vertical). And that worked.

So a whole lot of weirdness going on.

I vote yes, a bug. Yes please report it.

 

 

It also worked rotating both object together. So you actually get the exact object you were shooting for.

 

 

And even this worked.....

 

 

[alibali]

Ok JimmyJack I will do, thank you x