primarclen

float  primarclen(<geometry>geometry, vector2 uv1, vector2 uv2, int prim_num)

float  primarclen(<geometry>geometry, vector2 uv1, vector2 uv2, int prim_num, int divs)

float  primarclen(<geometry>geometry, vector2 uv1, vector2 uv2, int prim_num, int divs, int primuvmode)

float  primarclen(<geometry>geometry, vector2 uv1, vector2 uv2, int prim_num, int divs, int primuvmode, float primuvtol)

Returns the arc length between two parametric UV coordinates on a given primitive. This lets you measure the distance across a polygon face or along a curve.

geometry

A string specifying a geometry file (for example, a .bgeo) to read from. When running inside Houdini, this can be an op:/path/to/sop reference.

uv1

The start coordinate in the primitive’s parametric space to measure between.

uv2

The end coordinate in the primitive’s parametric space to measure between.

prim_num

The number of the primitive across which to measure the distance.

divs

The number of divisions per segment to use or 10 if not supplied.

primuvmode

Define the uv1 and uv2 coordinates units. See primuvconvert for the list of modes.

primuvtol

A tolerance used when computing the curve length to do uv coordinates conversions.

Tip

You can also read the arclength primitive intrinsic attribute to get a curve’s total arc length.