True darts tools


I am looking for explanation about the true darts tools. I found some explanations in dismine / Valentina / issues / #301 - True darts — Bitbucket

I know it requires 5 points:

  • 1 and 2 on the base line
  • 3 at the left top of the V
  • 4 at the bottom edge of the V
  • 5 at the right top of the V

It generates 2 points D1 and D2 to make the dart.

Is the geometry defined by these conditions:

  • |P4 D1| = |P4 D2|
  • angle(P1 D1, D1 P4) + angle(P2 D2, D2 P4) = 180°



I have never understood the purpose of this tool. What it is made for? This tool changes the place of the seam.

The truing of darts have different meaning for me. It is like in this video YouTube

The truing should extend the line A5-A2 to be equal to A5-A4


Yes, you are correct. The True-Darts tool should be improved. Would you please add this to the issues list?

I created a tool in the prototype accepted the three points of the dart, plus the points along the curve or line on both sides of the dart, plus choice of the side points where the fold should be directed.

Example: If the dart in the gif is to be folded towards A1, then the parameters would be A, A4, A5, A3, A1. The tool would return A6, A7, A8 where A8 is the extension point.

The results are a little more complex when the dart lies along a curve (like a dart along the back neckline). If A to A1 were a curve with c1 and c2 control points, then the tool would return a new curve from A to A6 with c1a and c1b control points, curve from A6 to A8 with c1c and c1d, curve from A8 to A7 with c2a and c2b, and curve from A7 to A1 with c2c and c2d.


I’ll add it in to issue list.


Thanks for this comment, i also stumpled yesterday about this tool and had the same thoughs.


was this ever resolved? I am just learning how to do darts, mostly on curves no less and just now trying to figure out this tool