Module com.marginallyclever.robotoverlord

Package com.marginallyclever.convenience.helpers

Class IntersectionHelper

java.lang.Object

com.marginallyclever.convenience.helpers.IntersectionHelper

public abstract class IntersectionHelper
extends Object

Convenience methods for detecting intersection of various mesh.

Constructor Summary

Constructors

Constructor	Description
IntersectionHelper()

Method Summary

Modifier and Type	Method	Description
static javax.vecmath.Vector3d	buildNormalFrom3Points(javax.vecmath.Vector3d v0, javax.vecmath.Vector3d v1, javax.vecmath.Vector3d v2)
static javax.vecmath.Vector3d	centerOfCircumscribedCircle(javax.vecmath.Vector3d a, javax.vecmath.Vector3d b, javax.vecmath.Vector3d c)	circumscribed circle
static javax.vecmath.Vector3d	centerOfCircumscribedSphere(javax.vecmath.Vector3d a, javax.vecmath.Vector3d b, javax.vecmath.Vector3d c, double r)	find the center of the sphere formed by the three points p and the radius.
static double	CPADistance(javax.vecmath.Vector3d a0, javax.vecmath.Vector3d b0, javax.vecmath.Vector3d a1, javax.vecmath.Vector3d b1)	find the closest point of approach between two lines
static boolean	cuboidCuboid(AABB a, AABB b)	separation of axes theorem used to find intersection of two arbitrary boxes.
static boolean	cylinderCylinder(Cylinder cA, Cylinder cB)	test intersection of two cylinders.
static boolean	meshMesh(javax.vecmath.Matrix4d ma, Mesh sa, javax.vecmath.Matrix4d mb, Mesh sb)
static double	rayBox(Ray ray, javax.vecmath.Point3d boxMin, javax.vecmath.Point3d boxMax)	find distance to box, if hit.
static double	rayPlane(Ray ray, Plane translationPlane)	Returns the distance to the plane, or Double.MAX_VALUE if there is no intersection.
static double	raySphere(Ray ray, javax.vecmath.Tuple3d center, double radius)	ray/sphere intersection.
static double	rayTriangle(Ray ray, javax.vecmath.Vector3d v0, javax.vecmath.Vector3d v1, javax.vecmath.Vector3d v2)	The implementation uses the Möller–Trumbore intersection algorithm to compute the intersection between a ray and a triangle.
static boolean	sphereBox(javax.vecmath.Tuple3d point, double r2, javax.vecmath.Tuple3d max, javax.vecmath.Tuple3d min)	is point within r of box (max,min)?

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

IntersectionHelper

public IntersectionHelper()

Method Details

cylinderCylinder

public static boolean cylinderCylinder(Cylinder cA,
 Cylinder cB)

test intersection of two cylinders. From ...

Parameters:

cA - cylinder A

cB - cylinder B

Returns:

true if intersect

CPADistance

public static double CPADistance(javax.vecmath.Vector3d a0,
 javax.vecmath.Vector3d b0,
 javax.vecmath.Vector3d a1,
 javax.vecmath.Vector3d b1)

find the closest point of approach between two lines

Parameters:

a0 - line 1 start

b0 - line 2 start

a1 - line 1 end

b1 - line 2 end

Returns:

distance between the two lines at the closest point of approach.

cuboidCuboid

public static boolean cuboidCuboid(AABB a,
 AABB b)

separation of axes theorem used to find intersection of two arbitrary boxes.

Parameters:

a - first cuboid

b - second cuboid

Returns:

true if cuboids intersect

meshMesh

public static boolean meshMesh(javax.vecmath.Matrix4d ma,
 Mesh sa,
 javax.vecmath.Matrix4d mb,
 Mesh sb)

Returns:

true if the two mesh intersect.

raySphere

public static double raySphere(Ray ray,
 javax.vecmath.Tuple3d center,
 double radius)

ray/sphere intersection. see reference.

Parameters:

ray - start and direction

center - center of sphere

radius - radius of sphere

Returns:

distance to first hit. negative values for no hit/behind start.

rayBox

public static double rayBox(Ray ray,
 javax.vecmath.Point3d boxMin,
 javax.vecmath.Point3d boxMax)

find distance to box, if hit. See scratchapixel

Parameters:

ray - start and direction

boxMin - lower bounds

boxMax - upper bounds

Returns:

>=0 for hit, negative numbers for hits behind the ray origin or no hit.

centerOfCircumscribedCircle

public static javax.vecmath.Vector3d centerOfCircumscribedCircle(javax.vecmath.Vector3d a,
 javax.vecmath.Vector3d b,
 javax.vecmath.Vector3d c)

circumscribed circle

Parameters:

a - point 1

b - point 2

c - point 3

Returns:

the center of the circumscribed circle.

centerOfCircumscribedSphere

public static javax.vecmath.Vector3d centerOfCircumscribedSphere(javax.vecmath.Vector3d a,
 javax.vecmath.Vector3d b,
 javax.vecmath.Vector3d c,
 double r)

find the center of the sphere formed by the three points p and the radius. see Stack overflow

Parameters:

a - point

b - point

c - point

r - radius

Returns:

the center of the sphere formed by the three points p and the radius.

rayTriangle

public static double rayTriangle(Ray ray,
 javax.vecmath.Vector3d v0,
 javax.vecmath.Vector3d v1,
 javax.vecmath.Vector3d v2)

The implementation uses the Möller–Trumbore intersection algorithm to compute the intersection between a ray and a triangle. The algorithm works by computing the intersection point between the ray and the plane defined by the triangle, and then checking if the intersection point is inside the triangle.
Note that this implementation assumes that the triangle is defined in a counter-clockwise winding order when viewed from the outside. If the triangle is defined in clockwise order, the direction of one of the cross products needs to be reversed to get the correct intersection result. See also Wikipedia.

Parameters:

ray - origin and direction

v0 - point 1

v1 - point 2

v2 - point 3

Returns:

distance to the intersection, negative numbers for hits behind camera, Double.MAX_VALUE for no hit.

rayPlane

public static double rayPlane(Ray ray,
 Plane translationPlane)

Returns the distance to the plane, or Double.MAX_VALUE if there is no intersection.

Parameters:

ray - origin and direction

translationPlane - plane

Returns:

the distance to the plane, or Double.MAX_VALUE if there is no intersection.

buildNormalFrom3Points

public static javax.vecmath.Vector3d buildNormalFrom3Points(javax.vecmath.Vector3d v0,
 javax.vecmath.Vector3d v1,
 javax.vecmath.Vector3d v2)

sphereBox

public static boolean sphereBox(javax.vecmath.Tuple3d point,
 double r2,
 javax.vecmath.Tuple3d max,
 javax.vecmath.Tuple3d min)

is point within r of box (max,min)?

Parameters:

point - the test point

r2 - the square of the radius

max - the max point of the box

min - the min point of the box

Returns:

true if point is within r of box (max,min)