Find the angle of a corner - Find relative rather than absolute line angles

Documentation / How to
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Hiya,

I’m new to using Seamly2D so I’m not sure if this is a feature that currently exists or not. I’ve searched the forum and can’t find another topic that relates to this, but if there is one please point me in that direction.

Essentially what I’m looking for is a digital protractor.

As far as I can tell all the angle measurements both provided by me and given back in the Tables of Variables are absolute, and based on the workspace i.e. 0/360 is right, 90 is straight up, etc. It took me a while to get my head around this, but after my thinking patterns adapted to it and it was okay.

However, now that I’m at the point where I need to fine tune the angles to ensure everything matches up properly it’s causing me trouble. I’m working with bra patterns and there are a lot of corner angles that need to match up in specific ways.

What I really need is to be able to easily see or calculate the angle of a corner on pattern peice. At the moment I’m getting the absolute angles of the two lines making up a corner and then calculating by hand the internal angle of that corner. This is really time consuming when I have 8 pieces each with 3 or 4 corners to calculate and match up.

I’ve taken to literally holding a protractor against the screen to get a rough idea before I calculate it all, which makes me feel completely ridiculous.

Is there currently an easier/better way to do this?

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In this situation I would draw several lines somewhere in free space and calculate angle of each as (Angle_line_1-Angle_line_2) so their absolute angles reflect relative angles you need. Easy to control visually - when lines point in one direction, angles are the same

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I’m not sure if I’m misunderstanding you or if my original post wasn’t clear is what I mean. It sounds like the way you’re suggesting to calculate the relative angles in the same way that I’m currently doing it.

Do you mean using increments? I haven’t played around with them much but copying the angles over to another section with increments set to measure the angles that way takes just as long as calculating it by hand, and setting the up is clunky so they don’t really work properly anyway.

The corners I’m wanting to get the angles for are already included in the drafted pattern. Rather than creating a new corner from scratch I’m wondering if there’s a quicker and easier way to find the angles of the corners I already have so that I can adjust them if necessary.

My current method of comparing the absolute angles with each other does work fine, it’s just fiddly and time consuming.

A protractor type feature that did the calculations for me would be helpful, because the data is already available to work with, but it sounds like this isn’t some that exists.

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Hi @MeganJoan, I understand that you’d like a ‘picture of a protractor’ that you could drag around and rotate, that you could drag around to measure angles with. And no, there’s nothing like this available.

When I used my protractor on my computer screen, it attached itself and it took me more time to get it out of the crevices at the edges of the screen than it took for me to check the angles :frowning:

However, what I think what @Krolich means is… that before you start a pattern, you create a small protractor on a Pattern Piece of its own, you can make its lines a light colour and move it out of the way (to one side) as you wish so that it doesn’t distract you, but the angles will be available to you to use while you are making the curves.

Here I’ve made you an example, you may add other degrees to it and use it as the base of any pattern that you create by opening it, saving it as a different name and open a new Pattern Piece to create your drawing:

Protractor.val (2.3 KB)

I hope this helps :smile:

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Oh I completely misunderstood that that’s what @Krolich meant! Thank you for clarifying. And thanks for the protractor pattern :slight_smile:

I can’t say I meant digital protractor that literally though haha More like a rule type tool where I could select two lines and it would give me the angle of the corner they create. But at least I have confirmation that such a tool definitely doesn’t exist and I’m just missing it. Unfortunately I don’t have the expertise to suggest adding it, either.

I’ll just carry on with my protractors and calculator.

When I used my protractor on my computer screen, it attached itself and it took me more time to get it out of the crevices at the edges of the screen than it took for me to check the angles :frowning:

This has happened to me too! So annoying.

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I’m not sure we understand each other at all :sweat: I will explain what I mean as good as I can

Here I drew two random triangles for demonstration.

image

Say, I need to compare angles A and A5. I will draw a line B_B1 and determine it’s angle with a formula: image

so that absolute angle of this line reflects relative angle between A_A1 and A_A2

Repeat with angle A5:

image

here I had to add -180 because the line on the drawing points in the opposite direction.

Now I have this picture

image

To make the angles equal I change lenghts of lines in triangles until lines B_B1 and B_B2 point in the same direction

image

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Hmmm… If you hover your cursor over a line, it gives the details of the line (see image below). If you jot them down somewhere and then hover over the 2nd line, and jot those down, you’ll be able to find the angle between the 2?

image

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Ahhhh okay! I understand what you mean now. Unfortunately that’s not really what I’m trying to do.

What I say matches up properly I mean ensure the angles will add up correctly to create a straight line when two of more pieces are sewn together, not make the angles the same.

I’m not after something complex like making one corner mimic another or anything like that, rather just a way to find out the angle of a corner. With your triangles for example, I would just want to be able to select the A/A1 line and then draw and arrow to the A1/A2 line and it would tell me 90 degrees. Literally just like a protractor. I want to say “these two lines of this corner” and get back an angle.

I’m essentially just doing your first step calculations with a pen, paper, and calculator rather than having the program calculate it for me, becuase in my case it’s quicker to just do it by hand and write it on an A3 sheet I’m using to keep track of everything.

Edit (because I ran out of posts on my first day):

Hmmm… If you hover your cursor over a line, it gives the details of the line (see image below). If you jot them down somewhere and then hover over the 2nd line, and jot those down, you’ll be able to find the angle between the 2?

Mine doesn’t show length and angle on hover; it might be a system dependant thing. But otherwise that’s exactly what I’m doing.

I have several ideas how to do it faster, but it really depends on the situation. It would help to see your pattern file

I honesty don’t think there is currently a way to calculate this faster than writing down the line angles and using a calculator unless an actual feature to calculate it by selecting lines in draw actually existed. Anything that takes longer than one or two steps in the draw screen itself would take longer.

It isn’t that it actually takes all that long to calcuate them by hand. It’s just that when your pattern has about 40 corners all of varying angles those small amounts of time add up. I was just wondering if there was a special tool that did it that I had missed, but I think we’ve establised that’s not the case.

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I have several ideas how to do it faster, but it really depends on the situation. It would help to see your pattern file

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I agree with @Krolich that it would be better to see the pattern so we can see what it is that will really help. (He’s really good with this sort of problem :slight_smile: ) Getting this problem sorted will pay dividends later when you want to grade the pattern.

It should but you may need to zoom in really close so that you can get the cursor exactly over the line.

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Hey, if I can do my math than I’m suddenly “he”? :joy:

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Haha, sorry :joy::joy::joy:

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I found very frustrating too the absolute angle calculation. to rotate a line/point 30 degree, we have to enter the angle of the first line minus the angle of the second line and repeat all the time we need to rotate that same value angle. Is there a way to keep that found angle in the table of variation with a name like angle a3 (the suffixe given by the rotation of that line, 30 degree in my exemple) . we could reuse that relative angle then, instead of re entering the whole formulae.

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For complicated patterns, I keep a text file with formulas and notes like (AngleLine_A1_A8-AngleLine_A1_A6) - breast dart and so on. I find it very useful

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You could use the formula of the new angle created in the next angle. All the angles previously created will be in the formula lists.