Description
Calculate a curved hem's allowance-length contribution under supplied geometry.
Garment geometry distinguishes body and finished dimensions, elastic rest length, seamline/cutline offsets, motif phases and joining losses. A nominal coordinate or length budget does not establish material behavior or a suitable fit. Direction, angle units and the number of gaps rather than objects affect the result.
Calculate a curved hem's allowance-length contribution under supplied geometry.
When to use this tool
Use Hem Curved Edge Allowance Length when checking the stated garment length, allowance, repeat or material-record convention.
How to use the tool and how it works
- Enter seamlineRadius, signedRadialAllowance, arcAngleRadians. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read cutlineRadius, cutlineArcLength, lengthDifference. Use the output convention below.
Require nonnegative seamline radius and cutline radius=seamlineRadius+signedAllowance, with arcAngleRadians>=0. Return cutline radius, radius*angle arc length and allowance*angle length difference.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| seamlineRadius | Seamline Radius | Required. Finite number; minimum 0. |
| signedRadialAllowance | Signed Radial Allowance | Required. Finite number. |
| arcAngleRadians | Arc Angle Radians | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| cutlineRadius | Cutline Radius | Required. Finite number. |
| cutlineArcLength | Cutline Arc Length | Required. Finite number. |
| lengthDifference | Length Difference | Required. Finite number. |
{
"input": {
"seamlineRadius": 10,
"signedRadialAllowance": 2,
"arcAngleRadians": 1.5
},
"output": {
"cutlineRadius": 12,
"cutlineArcLength": 18,
"lengthDifference": 3
}
}Limitations and assumptions
- The allowance is a signed radial offset; ideal concentric arcs do not model fabric deformation, seam easing or a recommended hem method.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use measured pattern/material properties, fitting evidence and appropriate complete production methods for actual garment fit and construction.
References
Similar or alternative tools
- Seamline Cutline Corner Bisector Offset
Calculate a seam-allowance offset along a convex corner's bisector.
- Seam Ease Per Length Tool
Compare supplied edge lengths against an explicit seam-length base, retaining signed ease.