Curve Analysis

Behavior

Validates whether a curve's endpoints connect, forming a complete loop. Returns true for closed curves, false for open ones.

Inputs

Curve

Outputs

Is Closed

Pairs With

Curve input, boolean output

Behavior

Computes the total path distance of a curve and returns it as a number.

Inputs

Curve

Outputs

Length

Pairs With

Curve, number length

Behavior

Converts a measured distance along a curve into its corresponding parameter value (t). The inverse of evaluating a point by parameter.

Inputs

Curve, Length

Outputs

Parameter

Pairs With

Curve, number length/parameter

Behavior

Determines the enclosed area within a closed planar curve. Returns the area as a number. Only works on closed, planar curves. Open curves or non-planar curves return 0 or undefined area.

Inputs

Curve

Outputs

Area

Pairs With

Closed planar curve, number area

Behavior

Returns the midpoint of a curve - the point located exactly halfway along its total length.

Inputs

Curve

Outputs

Midpoint

Pairs With

Curve, point

Behavior

Returns the start point and end point of the input curve.

Inputs

Curve

Outputs

Start, End

Pairs With

Curve, two points

Behavior

Returns a point located at a specified parameter along the curve. Parameter t ranges from 0 (start) to 1 (end). Default: Parameter 0.1. The parameter is normalized 0-1, not an absolute distance. On a 100-unit curve, t=0.5 gives the point at 50 units. For distance-based evaluation, use Evaluate Curve with the "By Length" toggle. Accepts a list of parameters - outputs a corresponding list of points.

Inputs

Curve, t

Outputs

Point

Pairs With

Curve, number parameter (0-1)

Behavior

Tests whether a point lies inside, outside, or on the boundary of a closed curve. Returns a numeric code: 0 = outside, 1 = on curve, 2 = inside.

Inputs

Curve, Point

Outputs

Result, Point

Pairs With

Closed curve, point, integer code

Behavior

Retrieves the underlying control points, knot vector, and weights that define a NURBS or spline curve's shape.

Inputs

Curve

Outputs

Points, Knots, Weights

Pairs With

NURBS curve, points, number arrays

Behavior

Separates an arc into its constituent elements: the plane it lies on, its radius, and start/end angles.

Inputs

Arc

Outputs

Plane, Radius, Angle 1, Angle 2

Pairs With

Arc, plane, number radius/angles

Behavior

Extracts detailed geometric information at any point along a curve: position, tangent vectors, and split lengths. Supports both parameter-based and length-based evaluation. The "By Length" toggle switches interpretation between parameter values (0-1) and actual distance measurements. Outputs both tangent directions and the lengths of curve segments on either side of the evaluation point.

Inputs

Curve, Parameter, By Length

Outputs

Point, Tangent 1, Tangent 2, Length 1, Length 2

Pairs With

Curve, number parameter, boolean toggle

Behavior

Confirms whether an entire curve lies within a single geometric plane. Returns true if planar, false if the curve is 3D (non-planar).

Inputs

Curve

Outputs

Is Planar

Pairs With

Curve, boolean output

Behavior

Finds the closest point on a curve to a reference point. Returns both the closest point and the distance to it.

Inputs

Curve, Point

Outputs

Closest, Distance

Pairs With

Curve, point, number distance

Behavior

Determines which side of a curve a point lies on, based on the curve's direction. Returns a side value (-1, 0, or +1) plus separate left/right boolean outputs.

Inputs

Curve, Point

Outputs

Side, Left, Right

Pairs With

Directed curve, point, integer/booleans

Behavior

Detects locations where a curve is not smooth - sharp corners, kinks, or breaks in tangent continuity. Returns the points at each discontinuity location. A smooth NURBS curve returns no discontinuities. A polyline returns every vertex as a discontinuity. Useful for quality-checking curves before lofting or sweeping.

Inputs

Curve

Outputs

Points

Pairs With

Curve, point list