AD: Making two shapes match edges exactly?

[casterle]

I've been practicing with shapes and have a problem I can't solve.

The attached file contains an oval and a cone. I want to make the cone 'attach' to the oval such that there are no gaps between the two. I can't seem to get the job done.

I've fairly new to vector graphics so I'm probably missing something obvious...

As always, thanks for your insight.

Shape Practice.afdesign

[iconoclast]

Hi casterle!

Did you try the Snap-function? You find it on top middle of the GUI, below the menu bar.

[casterle]

3 minutes ago, iconoclast said:

Hi casterle!

Did you try the Snap-function? You find it on top middle of the GUI, below the menu bar.

Thanks. The bottom curve of the oval and the top curve of the cone differ. I've tried using the node tool, but after an hour or so of frustration I turned to the forum for help.

If I understand your suggestion (using the magnet), I don't know how to use it to accomplish my goal.

[iconoclast]

Hm, I'm not sure if I exactly understand what you want to do. Do you want to set the shapes exactly side by side or do you want to set the cone on the oval like a hat..? The first thing should work with the Snap-function if you set it to "Snap to Object" (or so - my desktop computer is off at the moment, so I can't look for the right name). You could also do it with the Transform panel, by entering exact values for the positions, width and height of the shapes. Or you could use guidelines and/or a grid. You can also let the shapes snap to grids and guidelines.

The second solution should work by placing the shapes manually first and then, to align them exactly to the horizontal middle of each other, with the Align-function (six small buttons to align to the horizontal left, middle or right and the vertical left, middle or right). You should find it somewhere in the tool bar of the Move Tool. But both shapes have to be selected to align them.

Sorry, it is late here in Germany, and I have to go to bed. Will be back tomorrow.

[casterle]

1 hour ago, iconoclast said:

Hm, I'm not sure if I exactly understand what you want to do. Do you want to set the shapes exactly side by side or do you want to set the cone on the oval like a hat..? The first thing should work with the Snap-function if you set it to "Snap to Object" (or so - my desktop computer is off at the moment, so I can't look for the right name). You could also do it with the Transform panel, by entering exact values for the positions, width and height of the shapes. Or you could use guidelines and/or a grid. You can also let the shapes snap to grids and guidelines.

The second solution should work by placing the shapes manually first and then, to align them exactly to the horizontal middle of each other, with the Align-function (six small buttons to align to the horizontal left, middle or right and the vertical left, middle or right). You should find it somewhere in the tool bar of the Move Tool. But both shapes have to be selected to align them.

Sorry, it is late here in Germany, and I have to go to bed. Will be back tomorrow.

Do you have a way to look at the file? If so, what I want to do will be clear - I need to move the cone up (no problem with that!), and change it's upper curve to match the curvature of the oval precisely. In other words, I need to shape the bottom of the oval and the top of the cone to exactly match.

[GarryP]

I think the problem you are having is that you are trying to express a 3D design in 2D.
The ellipse won’t ‘fit’ the ‘cone’ because its 2D shape won’t fit inside the 2D shape of the ‘cone’.
What I think you need to do is manually apply ‘perspective’ by manipulating the ellipse.
See attached video for a crudely-done example (guide is used to make the manipulation a bit easier).

[iconoclast]

6 hours ago, casterle said:

Do you have a way to look at the file? If so, what I want to do will be clear - I need to move the cone up (no problem with that!), and change it's upper curve to match the curvature of the oval precisely. In other words, I need to shape the bottom of the oval and the top of the cone to exactly match.

Ah okay, I think I understand. In that case I would place both shapes as you need them, duplicate the oval, place its layer on top of the cone layer and Subtract it from the cone. Subtract is the second button of the Geometry options (on the right side of the context bar of the Move and Node tool.

It is often much easier and more precisely to do such things by cutting or extending them with duplicates of one of the shapes.

[GarryP]

iconoclast: Did you try the method you suggested and, if so, what result did you get?
I only ask as that sort of technique has not worked well for me in this type of situation.
I’ve attached a screenshot showing a similar thing but using clipping instead of the geometry functions – note how the ‘corners’ don’t look right.
Or have I misunderstood your instructions?

[iconoclast]

@GaryP: I see what you mean. It needs an additional step.

 

 

[Ron P.]

Is this what you're trying to do?

It seems the bottom (cone) curve was a little messed up at the left and right points. I corrected those. Then moved the nodes for the top elliptical curve to better match the bottom cone. I then moved the elliptical curve below the cone in the layer stack. Done the same with the hidden curve gradient fill. It helps hide some things that hard to get perfect.

I would recommend watching some tutorials about using the Isometric Grids, if your wanting to do this sort of things. Have a look at YouTube Channel by ArtistWright.

Shape Practice-1.afdesign

[thomaso]

5 hours ago, GarryP said:

I think the problem you are having is that you are trying to express a 3D design in 2D.
The ellipse won’t ‘fit’ the ‘cone’ because its 2D shape won’t fit inside the 2D shape of the ‘cone’.
What I think you need to do is manually apply ‘perspective’ by manipulating the ellipse.
See attached video for a crudely-done example (guide is used to make the manipulation a bit easier).

It might not matter for your sample, but generally your workflow makes me wonder:

From perspective view would it not be required to drag this node handles away from the object to maintain the perspective? At least theoretically the ellipse should get narrowed at its lower edge which represents to be more far away / in the background than the top / front most edge of the simulated 3D object. – Compare this illustration, exaggerated to make the difference more obvious:

[Old Bruce]

It has to do with the fact that the Ellipse shape should be cut in half early on so the outer bits at the bottom don't show.

Take a look at this and see if you understand what I mean.

cone.afdesign

[JimmyJack]

On 7/6/2022 at 5:51 PM, casterle said:

I've been practicing with shapes and have a problem I can't solve.

The attached file contains an oval and a cone. I want to make the cone 'attach' to the oval such that there are no gaps between the two. I can't seem to get the job done.

I've fairly new to vector graphics so I'm probably missing something obvious...

As always, thanks for your insight.

Shape Practice.afdesign 395.75 kB · 12 downloads

Seems like this thread has become two questions: 

1) the main title question. Making two shapes match edges exactly?
&
2) how to correctly draw a 2D version of a perspective cone.

Answers:

1) Among the other answers (which are fine and important to know), you can try this and possibly avoid a lot of work.
The old (actually not that old) "drag and hold to match edges exactly" trick. Just gotta make sure you have the same number of nodes.

2) Ellipses are circles in perspective. There's no need (and imho it's actually unwanted) to manipulate the oval to simulate perspective... unless you're going for some kind of Dali persistence of time oval 😉. It's all about where the side walls hit the ellipse boundary. Technically they'll never hit the ellipses' exact full width side nodes.... that would mean zero perspective.

[iconoclast]

17 hours ago, JimmyJack said:

...2) Ellipses are circles in perspective. There's no need (and imho it's actually unwanted) to manipulate the oval to simulate perspective... unless you're going for some kind of Dali persistence of time oval 😉. It's all about where the side walls hit the ellipse boundary. Technically they'll never hit the ellipses' exact full width side nodes.... that would mean zero perspective.

One annotation: It is true that the shape of a circle changes into a constant oval if you make a perspective transformation. But it is a bit more complicated if the circle contains a texture, as you can see on my attached image. While the outer shape is an oval, e.g. the initial horizontal middle axis moves nearer to the vanishing point - behind the (new) middle axis of the oval.

[JimmyJack]

On 7/8/2022 at 10:14 AM, iconoclast said:

One annotation: It is true that the shape of a circle changes into a constant oval if you make a perspective transformation. But it is a bit more complicated if the circle contains a texture, as you can see on my attached image. While the outer shape is an oval, e.g. the initial horizontal middle axis moves nearer to the vanishing point - behind the (new) middle axis of the oval.

Sure, the texture is the texture. That's all fine and good. I'm not sure how it makes things more complicated though 🤔. The shape is still the shape.

The oval is still a true oval, i.e. the nodes don't have to be manipulated to make the shape work correctly.
And the side walls don't connect to the side nodes. They hit a tangent beforehand.... even on a cylinder (in perspective). (Isometric is different of course). 🙂

 

[iconoclast]

As I said, the outer shape is in fact a consistent oval - as you said. I just wanted to point at this circumstance, that is important if you want to distort shapes that are tecturized. In fact this also means that points on the outline of the circle shape will move. Even if the shape becomes a consistent oval, it is distorted perspectivly from this point of view. Possibly this will have different effects to a circle shape than to a vector circle (a curve object). Haven't tried it, but it would make sense. Do you understand what I mean?

It was not a critic annotation. It was just for completion.

[JimmyJack]

16 hours ago, iconoclast said:

It was not a critic annotation. 

Oh no no. I didn't take it that way at all. I used smiley faces and everything 😄. I was just curious.

 

16 hours ago, iconoclast said:

Possibly this will have different effects to a circle shape than to a vector circle (a curve object). Haven't tried it, but it would make sense. Do you understand what I mean?

I think I do. I think you mean that in a real world, or virtual, 3D object  the mid points of the circle in perspective would in fact correspond to the texture midline of the image in perspective and not the end nodes of an 2d vertically squished circle masquerading as 3d. Even though they both appear visually the same in outline.

Below are two examples of that. One in 3d space, and the other with a 2d vector perspective filter (AI).... as opposed to only stretching an mage.

In order to draw the perspective 2d version by hand (since we don’t have a vector distort), then yes absolutely, in their placement "back" there on the curve, those node handles need to be at angles.

If you mean something else I apologize for prattling on. Explain more if you want. Or not. No biggie. 🍻

 

[casterle]

On 7/7/2022 at 1:29 AM, GarryP said:

I think the problem you are having is that you are trying to express a 3D design in 2D.
The ellipse won’t ‘fit’ the ‘cone’ because its 2D shape won’t fit inside the 2D shape of the ‘cone’.
What I think you need to do is manually apply ‘perspective’ by manipulating the ellipse.
See attached video for a crudely-done example (guide is used to make the manipulation a bit easier).

This method results in the oval overlapping the cone, hiding it's straight top. What I'm after is making the cone's top (or bottom in your example) exactly match the curve of the oval.

@iconoclast suggested using geometry, which produced the exact results I was looking for!

[casterle]

On 7/7/2022 at 1:29 AM, iconoclast said:

Ah okay, I think I understand. In that case I would place both shapes as you need them, duplicate the oval, place its layer on top of the cone layer and Subtract it from the cone. Subtract is the second button of the Geometry options (on the right side of the context bar of the Move and Node tool.

It is often much easier and more precisely to do such things by cutting or extending them with duplicates of one of the shapes.

Thank you! That gave me the exact results I was looking for. I'm fairly new to vector graphics and forgot all about the geometric functions.

[casterle]

On 7/7/2022 at 3:11 AM, Ron P. said:

Is this what you're trying to do?

It seems the bottom (cone) curve was a little messed up at the left and right points. I corrected those. Then moved the nodes for the top elliptical curve to better match the bottom cone. I then moved the elliptical curve below the cone in the layer stack. Done the same with the hidden curve gradient fill. It helps hide some things that hard to get perfect.

I would recommend watching some tutorials about using the Isometric Grids, if your wanting to do this sort of things. Have a look at YouTube Channel by ArtistWright.

Shape Practice-1.afdesign

Thank you. You're right, the cone was totally messed up at the upper corners. I couldn't figure out how to get the 'loop' effect out of the Bezier curve - so I gave up in frustration. @iconoclast suggested using geometry which is what I was looking for!

I've subscribed to ArtistWright's YouTube channel.

[casterle]

On 7/7/2022 at 2:58 PM, JimmyJack said:

Seems like this thread has become two questions: 

1) the main title question. Making two shapes match edges exactly?
&
2) how to correctly draw a 2D version of a perspective cone.

Answers:

1) Among the other answers (which are fine and important to know), you can try this and possibly avoid a lot of work.
The old (actually not that old) "drag and hold to match edges exactly" trick. Just gotta make sure you have the same number of nodes.

 

2) Ellipses are circles in perspective. There's no need (and imho it's actually unwanted) to manipulate the oval to simulate perspective... unless you're going for some kind of Dali persistence of time oval 😉. It's all about where the side walls hit the ellipse boundary. Technically they'll never hit the ellipses' exact full width side nodes.... that would mean zero perspective.

Thank you - that's impressive!

[iconoclast]

10 hours ago, JimmyJack said:

Oh no no. I didn't take it that way at all. I used smiley faces and everything 😄. I was just curious.

 

I think I do. I think you mean that in a real world, or virtual, 3D object  the mid points of the circle in perspective would in fact correspond to the texture midline of the image in perspective and not the end nodes of an 2d vertically squished circle masquerading as 3d. Even though they both appear visually the same in outline.

Below are two examples of that. One in 3d space, and the other with a 2d vector perspective filter (AI).... as opposed to only stretching an mage.

In order to draw the perspective 2d version by hand (since we don’t have a vector distort), then yes absolutely, in their placement "back" there on the curve, those node handles need to be at angles.

If you mean something else I apologize for prattling on. Explain more if you want. Or not. No biggie. 🍻

 

Yes, I think that is what I meant. I made a little mistake in thinking as I said that to convert the circle into curves would make a difference. That is of course not true. But if Designer would have a feature for perspective distortion, it would, because the horizontal middle nodes (middle axis) would move, as you showed in your example.

It's not important for simple graphics like in this case, but if you try something more detailed and realistic, it will become very important. Not only for texturized shapes, but also for e.g. cogwheels or other circle shapes with erratic edges.

[JimmyJack]

17 hours ago, iconoclast said:

Not only for texturized shapes, but also for e.g. cogwheels or other circle shapes with erratic edges.

A Cog (etc)! Oh my gosh yes. Totally different story.
The circle to oval is a special geometrical case. Everywhere, but special.