freesewing/markdown/dev/tutorials/pattern-design/fitting-the-neck-opening/de.md at 173b51eeb272f3bd77dce73c8feb23b8683ea12f

Joost De Cock b34a2ee2ed feat: Flat import of markdown repo

This is a flat (without history) import of (some of) the content
from our markdown module.

We've imported this without history because the repo contains our
blog posts and showcases posts content prior to porting them to strapi.

Since this contains many images, it would balloon the size of this repo
to import the full history.

Instead, please refer to the history of the (archived) markdown repo
at: https://github.com/freesewing/markdown

2021-08-25 16:09:31 +02:00

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title	order
Fitting the neck opening	170

Here's how we'll make sure the neck opening is just right:

let tweak = 1;
let target = (measurements.headCircumference * options.neckRatio) /4;
let delta;
do {
    points.right = new Point(tweak * measurements.headCircumference / 10, 0);
    points.bottom = new Point(0, tweak * measurements.headCircumference / 12);

    points.rightCp1 = points.right.shift(90, points.bottom.dy(points.right)/2);
    points.bottomCp2 = points.bottom.shift(0, points.bottom.dx(points.right)/2);

    paths.neck = new Path()
      .move(points.right)
      .curve(points.rightCp1, points.bottomCp2, points.bottom);

    delta = paths.neck.length() - target;
  if (delta > 0) tweak = tweak * 0.99;
  else tweak = tweak * 1.02;
} while (Math.abs(delta) > 1);

We've added a few new variables:

tweak: A tweak factor that we'll use to increase or decrease the neck opening by making it more or less than 1
target: How long our (quarter) neck opening should be
delta: How far we're off. Positive numbers mean it's too long, negative means too short

Now that we know what target is, we construct our path as we did before. But this time around, we multiply our point coordinates with our tweak variable (1 at the start).

Then, we compare our target to the result of paths.neck.length() which — you guessed it — returns the length of our neck path.

If the delta is positive, our path is too long and we reduce the tweak factor. If the delta is negative, our path is too short and we increase the tweak factor.

We keep on doing this until Math.abs(delta) is less than 1. Meaning that we are withing 1mm or our target value.

Now that we're happy with the length of our quarter neck opening, let's construct the entire neck opening.

1.9 KiB Raw Blame History

1.9 KiB

Raw Blame History