Is it possible to change the color of part of a line?

[KevinM1]

I'm attempting to make a simple logo for myself. The idea is that it's my initials, and I'd like the 'K' to be a different color than the 'M' (in this case, green). I created the vertical line with the pen's line tool, and it was easy enough to change the stroke color. The 'M' is made out of two pen-created polygons rotated (I made one, duplicated it, and then moved them to intersect with the vertical line). I want to color the '<' made by the overlapping shapes the same color as the vertical line, but I'm not sure how. I tried using the node tool to select the end point and intersection point of a line, but when I attempted to change the stroke color, it changed the color of the entire shape.

I could make two more straight lines and overlay the parts I want to change with them, but I feel like there must be an easier/more elegant solution I'm missing. Any guidance is greatly appreciated.

Thanks!

logo.afdesign

[Komatös]

Hello and welcome to the forums @KevinM1

Use the knife tool  and cut the lines at the points marked in red.  To do this, the layers representing the M must be selected. You can now adjust the colour of the newly created sections to the vertical line.

[GarryP]

An alternative in this case might be to use the Node Tool to Break the Curve at the relevant points before recolouring. (You will need to add a new node on one of the curves where the curve meets the green curve.)

See attached video (which was recorded in Photo, but all three applications work the same in this regard).

[ronnyb]

There are reasons NOT to use the following method, but you could apply a gradient to the Stroke of your object and using overlapping color stops along the gradient, create the effect your original post’s title asks…

Nailing the angle of the (linear?) gradient in the right direction seems the only critical part of the process…

[R C-R]

10 hours ago, Komatös said:

Use the knife tool  and cut the lines at the points marked in red.  To do this, the layers representing the M must be selected. You can now adjust the colour of the newly created sections to the vertical line.

I must be doing something stupid because when I use the Knife tool & just click on the nodes you show circled in red (as opposed to trying to draw a cut through them) so the tool changes to the scissor shape, it doesn't seem to actually cut the lines until/unless I then use the Divide button to separate them into two parts.

The same thing happens in a new document with just a single line -- clicking on any of its nodes with the Knife Tool does not cut it into two curves until I use the divide button. IIRC, clicking on a node with the Knife tool used to cut it into two curves so is this maybe a bug in the current 2.5.7 version? The drag-cut method still works to automatically split the curve into multiple parts so it is just the click cut that isn't working as I expected.

[Ldina]

43 minutes ago, R C-R said:

it doesn't seem to actually cut the lines until/unless I then use the Divide button to separate them into two parts.

It does cut the line, because you can select the node you cut with the scissors and move it, which shows the visible cut. But for whatever reason, recoloring, changing stroke width, etc, affects all those previously cut segments. You can see that the cut segments are all still on a single layer, so they are treated as one.

Like you, I had to use Boolean Divide to separate the scissor cuts into their own individual layers. I guess that could come in handy, depending on what you want to do after cutting, but it was unexpected behavior (at least to me). Divide works fine, as long as you know you need to do that. 

What's counter-intuitive to me is that the knife automatically puts the cut segments onto their own individual layers. I'd have thought the knife and scissors would work the same, but they don't, at least in v2.5.7 on Mac. Not sure about Windows or earlier versions. 

[R C-R]

38 minutes ago, Ldina said:

It does cut the line, because you can select the node you cut with the scissors and move it, which shows the visible cut.

I cannot do that with the Knife (scissors) tool but I can with the Node Tool. But regardless, in the Layers panel the two parts are displayed as just one Curve (not Curves) layer, which I think is not the expected behavior.

49 minutes ago, Ldina said:

What's counter-intuitive to me is that the knife automatically puts the cut segments onto their own individual layers. I'd have thought the knife and scissors would work the same, but they don't, at least in v2.5.7 on Mac.

Not sure what you mean. There is only one Knife tool; it just has two modes, clicking (which uses the scissors icon) & dragging (which uses the Knife icon). From the help topic:

Quote

A scissor-cut feature also lets you click on any open curve to break the curve at a chosen node or anywhere on a curve segment; a polycurve is created.

 This implies to me that it should result in the same "polycurve" (which I assume means a Curves layer in Affinity-speak) regardless of where the scissors-cut is done. But it doesn't. If I use the Boolean add on the cut open curve (which as expected causes it do disappear) & then undo that, the Layers panel updates correctly to show that it is a Curves layer, but I think it should not be necessary to do that.

[KevinM1]

12 hours ago, GarryP said:

An alternative in this case might be to use the Node Tool to Break the Curve at the relevant points before recolouring. (You will need to add a new node on one of the curves where the curve meets the green curve.)

See attached video (which was recorded in Photo, but all three applications work the same in this regard).

Went with this solution because of the video. Thanks so much to everyone that answered! It's nice having 3-4 ways to do something in my toolbox.

[Ldina]

11 minutes ago, R C-R said:

it just has two modes

Of course, that's what I meant.

11 minutes ago, R C-R said:

I cannot do that with the Knife (scissors) tool but I can with the Node Tool.

Either one works for me.

It is what it is. Knife Mode automatically puts segments onto separate layers. Scissors Mode doesn't. At least that's my experience. Both modes work fine. I just didn't expect I'd have to manually separate the segments using Boolean Divide after using Scissors mode. 

[R C-R]

52 minutes ago, Ldina said:

Either one works for me.

So you are saying that you can use the Knife Tool to move a node that you have cut using scissors mode? I cannot do that -- with the Knife Tool selected I cannot move any node. I always have to switch to the Node tool to do that.

[lepr]

48 minutes ago, R C-R said:

with the Knife Tool selected I cannot move any node. I always have to switch to the Node tool to do that.

At the bottom of the app window is the status bar. It's not a new feature. You use a Mac, therefore when the Knife Tool is active, the status bar will tell you that the cmd key temporarily enables the Node Tool, which will allow you to move nodes.

[Ldina]

51 minutes ago, R C-R said:

So you are saying that you can use the Knife Tool to move a node that you have cut using scissors mode? I cannot do that -- with the Knife Tool selected I cannot move any node. I always have to switch to the Node tool to do that.

Let's start with an open curve on a single layer...

The knife mode will slice the curve in half, and will automatically place each "half" on it's own layer, so you will now have two layers, where before you had only one. I can then use the Move or Node tool as I would with any normal open curve.

The scissors mode (used once, in this simple example) will cut the curve, however both "halves" will remain on the original layer (i.e., no second layer will be created). So, whatever you do to that layer will affect both halves, even though they have been "cut". At this point, I can use the Node tool to manipulate each half as desired. The move tool will move them together, since they are on ONE layer and share a bounding box. If I want them on their own separate layers, I used the Divide operator. 

And....what @lepr just posted (as I am finishing this post). 

 

 

 

[lepr]

2 hours ago, R C-R said:

But regardless, in the Layers panel the two parts are displayed as just one Curve (not Curves) layer, which I think is not the expected behavior.

That failure of the Layers panel to update with a change from Curve to Curves is an ancient bug that occurs with several operations. The update will accompany the next update that happens in the Layers panel.

2 hours ago, R C-R said:

If I use the Boolean add on the cut open curve (which as expected causes it do disappear) & then undo that, the Layers panel updates correctly to show that it is a Curves layer, but I think it should not be necessary to do that.

Well, that is not necessary. Performing a Boolean Add then undoing it is overkill. You could simply toggle the visibility or lock status of the object (or any other object) to force an update of the Layers panel.

[lepr]

21 minutes ago, Ldina said:

If I want them on their own separate layers, I used the Divide operator. 

There is also the Separate Curves command, and a button for it can be added to the main toolbar.

[R C-R]

1 hour ago, lepr said:

At the bottom of the app window is the status bar. It's not a new feature. You use a Mac, therefore when the Knife Tool is active, the status bar will tell you that the cmd key temporarily enables the Node Tool, which will allow you to move nodes.

Which is why I said "I always have to switch to the Node tool to do that." 

1 hour ago, Ldina said:

So, whatever you do to that layer will affect both halves, even though they have been "cut". At this point, I can use the Node tool to manipulate each half as desired.

See above.

[R C-R]

50 minutes ago, lepr said:

Well, that is not necessary. Performing a Boolean Add then undoing it is overkill. You could simply toggle the visibility or lock status of the object (or any other object) to force an update of the Layers panel.

I did not mean the undo was the only way to force the update, but regardless I will stand by my assertion that it should not be necessary to do anything for it to update.

[R C-R]

52 minutes ago, lepr said:

There is also the Separate Curves command, and a button for it can be added to the main toolbar.

It is also part of the Geometry button group so if there is room for that 5 button group on the toolbar it can be very handy.

[Komatös]

13 hours ago, R C-R said:

I must be doing something stupid

Here you can see how I did it!

[lepr]

9 hours ago, R C-R said:

I will stand by my assertion that it should not be necessary to do anything for it to update.

Of course. As I said, the lack of update is an ancient bug. It’s from long before the introduction of the Knife Tool. 

[GarryP]

Another method would be to Merge the Curves (menu “Layer → Geometry → Merge Curves”), then Expand the Stroke (menu “Layer → Expand Stroke), and then clip a blue-coloured shape to those expanded curves.

See attached image where the blue-coloured shape is selected so you can see what’s been done a bit better.

It’s not something I would recommend in this particular case (it makes the design more difficult to edit for a start), but it’s worth knowing about in case it’s useful elsewhere.

[lepr]

10 hours ago, R C-R said:

It is also part of the Geometry button group so if there is room for that 5 button group on the toolbar it can be very handy.

I should have mentioned that since it's what I actually use.

[R C-R]

6 hours ago, Komatös said:

Here you can see how I did it!

OK, but using 'knife mode' like that is imprecise -- it is hard to make the cut pass exactly through a node rather than a bit to one side, resulting in extra nodes.

[Komatös]

2 hours ago, R C-R said:

OK, but using 'knife mode' like that is imprecise

One additional node is created per cut, but these extra nodes can be deleted without much effort.

[R C-R]

1 hour ago, Komatös said:

One additional node is created per cut, but these extra nodes can be deleted without much effort.

However, the extra node may be so close to the one you are aiming for that you may have to zoom in very, very far just to notice that it has been added, & it may be hard to decide which one should be deleted.

So to sum it all up, the simplest, most accurate, & fastest way to cut the line apart is to do what @GarryP suggested & use the Node Tool to break it at a node. You can also get guaranteed accurate results using the scissor-cut plus boolean divide method at the cost of one more step. Your method may or may not require more steps & more effort to get accurate results, so to me it seems the least desirable one.

As always, YMMV. 😉