ray-3d

A high-level ray picking helper for 3D intersection, built from modular pieces.

var Ray = require('ray-3d')
 
var ray = new Ray(origin, direction)
 
if (ray.intersectsSphere(center, radius)) {
  console.log("Hit a sphere!")
}

Features:

• intersectsSphere
• intersectsPlane
• intersectsTriangle
• intersectsTriangleCell
• intersectsAABB (Axis-Aligned Bounding Box)

The API is still experimental, and missing some features:

• ray-ray-intersection
• ray-mesh-intersection (simplicial complex)

Usage

ray = new Ray([origin, direction])

Creates a new Ray with optional origin and direction, both arrays in the form [x, y, z].

origin defaults to [0, 0, 0] and direction defaults to [0, 0, -1].

ray.set(origin, direction)

Assigns this ray's origin and direction to the given values.

ray.copy(otherRay)

Copies the origin and direction from the otherRay into this ray.

otherRay = ray.clone()

Deep clones this ray into a new Ray instance.

---

intersections

All intersection methods return the collision point [x, y, z] if one occurred, which is re-used across calls to avoid GC thrashing.

If no collision occurred, the methods return null.

ray.intersectsPlane(normal, distance)

Whether this ray intersects the plane with the unit normal [x, y, z] and distance from origin.

ray.intersectsSphere(center, radius)

Whether this ray intersects with the sphere at center [x, y, z] and radius.

ray.intersectsTriangle(triangle)

Whether this ray intersects with the triangle:

[ [x1, y1, z1], [x2, y2, z2], [x3, y3, z3] ]

ray.intersectsTriangleCell(cell, positions)

Whether this ray intersects with the triangle cell, where cell is a face like so:

[ a, b, c ]

Where [ a, b, c ] are indices into the positions array:

[ [x1, y1, z1], [x2, y2, z2] ... ]

This is useful for indexed meshes and simplicial complexes like icosphere.

ray.intersectsBox(aabb)

Whether this ray intersects with the Axis-Aligned Bounding Box aabb:

[ [x1, y1, z1], [x2, y2, z2] ]

See Also

• camera-unproject
• camera-project
• camera-picking-ray
• ray-sphere-intersection
• ray-plane-intersection
• ray-triangle-intersection
• ray-aabb-intersection

License

MIT, see LICENSE.md for details.