Ray3

Ray3 (from scenerystack/dot) is the 3D counterpart to Ray2: an origin position and a unit-length direction, both Vector3 instances. It's the representation used for picking/intersection queries in 3D-flavored code — for example, mobius's 3D scenes — such as "does this mouse ray hit that sphere or plane."

import { Ray3, Vector3 } from 'scenerystack/dot';

const ray = new Ray3( new Vector3( 0, 0, 5 ), new Vector3( 0, 0, -1 ) ); // pointing toward the origin

ray.pointAtDistance( 5 );          // Vector3(0, 0, 0) — 5 units along the ray from its origin
const shifted = ray.shifted( 2 );  // a new Ray3 with the same direction, origin moved 2 units along it

Constructing

new Ray3( position: Vector3, direction: Vector3 )

Both fields are plain public properties. direction must be a unit vector — an assertion in development builds checks Math.abs( direction.magnitude - 1 ) < 0.01 and throws if it's off, exactly as with Ray2.

Methods

Method	Effect
pointAtDistance( distance )	position.plus( direction.timesScalar( distance ) ) — the point reached by walking distance along the ray
shifted( distance )	A new Ray3 with the same direction, whose origin is pointAtDistance( distance )
distanceToPlane( plane )	The signed distance along the ray at which it crosses a given Plane3
toString()	Debug string showing position and direction

Intersecting a ray with a plane

Ray3 itself only computes the distance to a plane; combine it with Plane3.intersectWithRay() to get the actual intersection point:

import { Ray3, Plane3, Vector3 } from 'scenerystack/dot';

const ray = new Ray3( new Vector3( 0, 0, 5 ), new Vector3( 0, 0, -1 ) );

const hitPoint = Plane3.XY.intersectWithRay( ray ); // Vector3(0, 0, 0)

There's no Ray3-vs-sphere or Ray3-vs-triangle method on Ray3 itself

Ray3 is a minimal data holder, like Ray2 — it only knows how to walk along itself and measure distance to a plane. Sphere-ray intersection lives as the standalone sphereRayIntersection function (also exported from scenerystack/dot), and triangle/mesh picking is handled by the consuming 3D code (e.g. mobius), not by Ray3 itself.