@Test
public void testLerp() {

  final Vector3 vec1 = new Vector3(8, 3, -2);
  final Vector3 vec2 = new Vector3(2, 1, 0);
  assertEquals(new Vector3(5, 2, -1), vec1.lerp(vec2, 0.5, null));
  assertEquals(new Vector3(5, 2, -1), vec1.lerp(vec2, 0.5, new Vector3()));
  assertEquals(new Vector3(5, 2, -1), Vector3.lerp(vec1, vec2, 0.5, null));
  assertEquals(new Vector3(5, 2, -1), Vector3.lerp(vec1, vec2, 0.5, new Vector3()));
  vec1.set(14, 5, 4);
  vec1.lerpLocal(vec2, 0.25);
  assertEquals(new Vector3(11, 4, 3), vec1);
  vec1.set(15, 7, 6);
  final Vector3 vec3 = new Vector3(-1, -1, -1);
  vec3.lerpLocal(vec1, vec2, 0.5);
  assertEquals(new Vector3(8.5, 4.0, 3.0), vec3);
  // coverage
  assertEquals(vec1.lerp(vec1, .25, null), vec1);
  assertEquals(vec2.lerpLocal(vec2, .25), vec2);
  assertEquals(vec2.lerpLocal(vec2, vec2, .25), vec2);
  assertEquals(Vector3.lerp(vec1, vec1, .25, null), vec1);
}