Ray2d.md

Ray2d Class

Overview

The Ray2d class represents a half-bounded line in 2D space (XY plane), defined by a base point and a direction vector.

Namespace

Autodesk.AutoCAD.Geometry

Key Properties

Property	Type	Description
BasePoint	Point2d	Gets the starting point of the ray
Direction	Vector2d	Gets the direction vector of the ray

Key Methods

Method	Return Type	Description
GetClosestPointTo(Point2d)	Point2d	Gets closest point on ray
DistanceTo(Point2d)	double	Gets distance from point to ray
IsOn(Point2d)	bool	Checks if point is on ray

Code Examples

Example 1: Creating 2D Rays

Point2d basePoint = new Point2d(0, 0);
Vector2d direction = new Vector2d(1, 1).GetNormal();

Ray2d ray = new Ray2d(basePoint, direction);

ed.WriteMessage($"\n2D Ray from {ray.BasePoint} in direction {ray.Direction}");

Example 2: 2D Ray Casting

Ray2d ray = new Ray2d(new Point2d(0, 0), new Vector2d(1, 0));
Point2d testPoint = new Point2d(10, 5);

Point2d closestPoint = ray.GetClosestPointTo(testPoint);
double distance = ray.DistanceTo(testPoint);

ed.WriteMessage($"\nClosest point: ({closestPoint.X:F2}, {closestPoint.Y:F2})");
ed.WriteMessage($"\nDistance: {distance:F2}");

Best Practices

1. 2D Performance: Use Ray2d for planar ray casting (faster than 3D)
2. Direction: Normalize direction vector
3. Half-Bounded: Extends from base point in one direction only

Related Classes

• Ray3d - 3D half-bounded line
• Line2d - Unbounded 2D line
• LineSegment2d - Bounded 2D line segment

References

• Autodesk Official Documentation
• Ray2d Class Reference