Cut a Path (split)

[dannys81]

Hello, Im new to graphic design. I would like to know how to cut path on eclipse, just leave the middle part. Im not sure how to exactly explain this let me try to post a picture on.

 

[Callum]

Hi dannys81,

Welcome to the forums

I'm not sure If I understand this issue correctly. Are you trying to cut the black curves out of the white background?

Thanks

Callum

[dannys81]

Hi Callum, 

Thank you for your reply.  I don't blame you of not understanding my question, its hard for me to explain.

I watch this on youtube this guy is doing it with Inkscape, I can post the link here not sure if this is allowed. 

https://www.youtube.com/watch?v=OT97oRXZiVY

The mentioned clip in between 21:05 - 21:36.

Thanks, 

Danny

[gdenby]

Hi, dannys81,

Here's an Affinity method. 

Have snapping turned on. Draw a circle/ellipse. If you like, position the center at the center of the spread.

Make the circle's fill none, and set the stroke to whatever thickness you want. Then draw a rectangle of desired size that spans the circle. Because snapping is on, you will see when the rectangle is centered on the circle.

You will notice it is positioned above the circle in the layer hierarchy. This is necessary for the next operation.

Select both, and use the boolean subtract widget. 

Here is where the procedure appears to me to differ from Inkscape.

The rectangle is subtracted away, leaving 2 parts of the original circle. Using the node tool, select the 4 inner nodes, and then use the "break curve" widget. There will then be 2 straight line curves, and 2 arcs. Delete the lines.

My opinion is that it is not a good way to learn to use Affinity by watching other apps tutorials. I've been using various vector programs for about 30 years now, and it still took me at least 2 weeks just getting settled into Designer. It took me a couple of months to stop using keyboard short cuts I half remembered from other apps. Not all features are implemented thesame as in other apps, and some have not been written yet. I figure its better to practice w. what is at hand, so that I can add new skills as new tools are added.

[dannys81]

Hi Gdenby,

Thank you very much. I will give it a try. I will let you know the outcome. You guys are very talented!! Im pretty sure Affinity Designer is not the first software used in designing. 

Regards,

Danny

[R C-R]

An alternative method you might find interesting for educational purposes is to use Affinity's 'quick shapes' to create the two paths. One way to do that is to use the donut tool to create the two parts individually, taking advantage of snapping to make the two parts symmetrical. You might want to use this method so you can easily thicken the two parts or give them separate fill & stroke properties.

This Donut method.afdesign file includes the history so you can use the history slider to see the steps, but some of it may not be obvious so the below may help with that.

[dannys81]

Hi RCR

i must say you guys are very helpful. Got the respond very quick. Very pleased with the experience!!

Danny

[firstdefence]

1. Draw an ellipse
2. Draw a rectangle to it sits over the middle of the ellipse like so
   1. 
3. Now do a Geometry: Subtract and you should now have this
   1. 
4. While the object is still selected do a Geometry: Divide, this will separate the left and right shapes into their own layer
   1. 
5. Again while the shapes are still selected, Select the Node Tool and drag over the four inner nodes
   1. 
6. and from the context menu just above the workspace select Action: Break Curve (first Icon)
7. Now delete the layers shown in the image below
   1. 
8. You should now have this
   1. 

[Alfred]

51 minutes ago, gdenby said:

Make the circle's fill none, and set the stroke to whatever thickness you want. Then draw a rectangle of desired size that spans the circle. Because snapping is on, you will see when the rectangle is centered on the circle.

To do it exactly as in the video, instead of a rectangle you would use two diamond shapes which have been Boolean added to create a single ‘Curves’ object.

[dannys81]

29 minutes ago, Alfred said:

To do it exactly as in the video, instead of a rectangle you would use two diamond shapes which have been Boolean added to create a single ‘Curves’ object.

Hi Alfred,

By the way what is Boolean?

[Alfred]

23 minutes ago, dannys81 said:

Hi Alfred,

By the way what is Boolean?

Boolean operators are the ones (‘Add’, ‘Subtract’, ‘Intersect’, etc) for which you’ll find buttons in the Geometry section of the main toolbar.

[gdenby]

1 hour ago, Alfred said:

To do it exactly as in the video, instead of a rectangle you would use two diamond shapes which have been Boolean added to create a single ‘Curves’ object.

I couldn't follow most of what the fellow did. I don't use Inkscape enough, and the version shown is somewhat later than mine. I didn't see any reason why using diamonds was necessary in this situation. I supposed it might be to cut a bevel, but that seemed to me from what I could see of the vid that that wasn't needed. 

[Alfred]

6 minutes ago, gdenby said:

I didn't see any reason why using diamonds was necessary in this situation. I supposed it might be to cut a bevel

That’s the only difference, as far as I can see. If you aren’t concerned about the angle at the ends of the arcs, it doesn’t matter which way you do it.

[John Rostron]

2 hours ago, dannys81 said:

By the way what is Boolean?

Boolean is named after the mathematician George Boole. He invented a form of arithmetic where the operands were either TRUE or FALSE. This arithmetic is widely used in computing where a binary digit is either TRUE (1) or FALSE (0). The labelling of these geometrical operations as Boolean is a bit tenuous, but is widely used in graphics.

John

[lepr]

.

[John Rostron]

9 minutes ago, >|< said:

I disagree with tenuous. For a given object (the result of a Boolean operation), any location in space (on the canvas/page, in the case of an Affinity document) is either contained in the object or not contained in the object.

OK, perhaps not so tenuous. The operations for combine and intersect, for example, have equivalences in the use of Venn Diagrams which are used in set operations, closely related to strict Boolean Arithmetic.

John

[R C-R]

9 minutes ago, >|< said:

For a given object (the result of a Boolean operation), any location in space (on the canvas/page, in the case of an Affinity document) is either contained in the object or not contained in the object.

@dannys81, in case you were wondering, that is why the boolean operators are in the Geometry section of the toolbar & in the Layer menu.

[v_kyr]

1 hour ago, John Rostron said:

This arithmetic is widely used in computing where a binary digit is either TRUE (1) or FALSE (0).

That's somehow too short and flat described for computing, where we use boolean vars with boolean algebra or boolean data types in prog languages. - For graphics the following (boolean operations on polygons) gives a quick overview.

[John Rostron]

1 hour ago, v_kyr said:

That's somehow too short and flat described for computing

True, but I didn't think that a full exposition was needed in this context.

John

[v_kyr]

19 minutes ago, John Rostron said:

True, but I didn't think that a full exposition was needed in this context.

My motto here is, better a little more than not enough, in the overall hope that people will deal with it then more deeply and gain a better understanding. - It's maybe also good for later (re)referencing, so you don't have to explain again in full, just point to the once given here detailed explanation or references then.

[dannys81]

9 hours ago, Alfred said:

Boolean operators are the ones (‘Add’, ‘Subtract’, ‘Intersect’, etc) for which you’ll find buttons in the Geometry section of the main toolbar.

Ahh got it. 

Thanks. 

[dannys81]

7 hours ago, John Rostron said:

Boolean is named after the mathematician George Boole. He invented a form of arithmetic where the operands were either TRUE or FALSE. This arithmetic is widely used in computing where a binary digit is either TRUE (1) or FALSE (0). The labelling of these geometrical operations as Boolean is a bit tenuous, but is widely used in graphics.

John

Hi John, 

Now this is another knowledge logged in. Thanks for the info!!

Regards, 

Danny

[dannys81]

6 hours ago, R C-R said:

@dannys81, in case you were wondering, that is why the boolean operators are in the Geometry section of the toolbar & in the Layer menu.

Yes, after explanation Im getting into the language now. You guys are an expert here really!!