API Reference > geometry-core > Curve > CurveChainWithDistanceIndex > isInPlane isInPlane Method Ask if the curve is within tolerance of a plane. isInPlane(plane: Plane3dByOriginAndUnitNormal): boolean Parameter Type Description plane Plane3dByOriginAndUnitNormal Returns - boolean Returns true if the curve is completely within tolerance of the plane. Defined in curve/CurveChainWithDistanceIndex.ts Line 227 Last Updated: 12 June, 2024