Description
Calculate a seam-allowance offset along a convex corner's bisector.
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 seam-allowance offset along a convex corner's bisector.
When to use this tool
Use Seamline Cutline Corner Bisector Offset when checking the stated garment length, allowance, repeat or material-record convention.
How to use the tool and how it works
- Enter seamAllowance, interiorAngleRadians. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read bisectorOffset. Use the output convention below.
Require seamAllowance>=0 and interiorAngleRadians strictly between zero and π. Return allowance/sin(angle/2) as the distance along the corner bisector.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| seamAllowance | Seam Allowance | Required. Finite number; minimum 0. |
| interiorAngleRadians | Strictly between zero and π; offset is measured along the corner bisector. | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| bisectorOffset | Bisector Offset | Required. Finite number. |
{
"input": {
"seamAllowance": 1,
"interiorAngleRadians": 1.5707963267948966
},
"output": {
"bisectorOffset": 1.4142135623730951
}
}Limitations and assumptions
- Assumes two straight offset seam edges at the supplied interior angle; no fabric behavior, trimming or manufacturing suitability is evaluated.
- 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
- Hem Curved Edge Allowance Length
Calculate a curved hem's allowance-length contribution under supplied geometry.
- Seam Allowance Cutline Offset Tool
Offset a straight seamline coordinate by a nonnegative allowance in an explicit outward axis direction.