OK, so this problem keeps eluding me: **How can I extract sub-segments from (anywhere on) a base curve without the segment-lengths being influenced by the curvature?**

I want to do the following **using C#**, Example:

- Pick two subcurves, A & B, with the
**same**“true”**curve length** - Query using “true” length for both subcurves (say 10mm interval out of a 100 mm long curve)
- Query using parameter values (0.1 out of a 1.0 long curve).
- Again, in both cases (2 & 3) I want the curve segments to be equally long (within some tol)

**Fig.** The SubCurve **B** can start at any point on the curve, illustrated by placing **B** where the curvature is much different from SubCurve **A**.

I know how to perform a simple curve division with equal length curve segments like so:

```
var crv_points = new List<Point3d>();
double t;
var seg_param = 1.0 / segment_count; // segments as parameterized size
for (int i = 0; i < segment_count; i++)
{
curve.NormalizedLengthParameter(seg_param * i, out t);
crv_points.Add(curve.PointAt(t);
}
```

… but I fail to get extract equal length sub-segments (starting from *any point* on the curve) without their length being influenced by the curvature.

// Rolf