gistfile1.java

	public static boolean checkCollision(BoundingBox a, Plane b) {
		boolean pos = (a.min.dot(b.normal) > 0);
		return pos != (a.max.dot(b.normal) > 0) //Planes that are axis-aligned. most cases
			//X N N
			|| pos != (new Vector3(a.max.getX(), a.min.getY(), a.min.getZ()).dot(b.normal) > 0)
			//N X N
			|| pos != (new Vector3(a.min.getX(), a.max.getY(), a.min.getZ()).dot(b.normal) > 0)
			//N N X
			|| pos != (new Vector3(a.min.getX(), a.min.getY(), a.max.getZ()).dot(b.normal) > 0)
			
			//N X X
			|| pos != (new Vector3(a.min.getX(), a.max.getY(), a.max.getZ()).dot(b.normal) > 0)
			//X N X
			|| pos != (new Vector3(a.max.getX(), a.min.getY(), a.max.getZ()).dot(b.normal) > 0)
			//X X N
			|| pos != (new Vector3(a.max.getX(), a.max.getY(), a.min.getZ()).dot(b.normal) > 0);
	}

unittest.java

	@Test
	public void testCheckCollision_BoundingBox_Plane() {
		System.out.println("checkCollision");
		BoundingBox a = new BoundingBox(
			new Vector3(-1, -1, -1),
			new Vector3(1, 1, 1));

		Plane b = new Plane(
			new Vector3(0, 0, 0),
			Vector3.Up);

		boolean result = CollisionHelper.checkCollision(a, b);

		assertTrue(result);

		//Check slanted plane

		b = new Plane(
			new Vector3(0, 0, 0),
			new Vector3(1, 1, 1).normalize());

		result = CollisionHelper.checkCollision(a, b);

		assertTrue(result);

		//Check non intersecting

		b = new Plane(
			new Vector3(-2, -2, -2),
			Vector3.Up);

		result = CollisionHelper.checkCollision(a, b);

		assertFalse(result);
	}