public void TestAddFlexibleInPlace()
{
Random rnd = new Random(2);
Vector3 p1 = RandomUtil.Vector3(rnd); float m1 = RandomUtil.PositiveFloat(rnd);
Vector3 p2 = RandomUtil.Vector3(rnd); float m2 = RandomUtil.PositiveFloat(rnd);
Vector3 p3 = RandomUtil.Vector3(rnd); float m3 = RandomUtil.PositiveFloat(rnd);
MassMoment momentToAdd = new MassMoment();
momentToAdd.AddInplace(m1, p1);
momentToAdd.AddInplace(m2, p2);
momentToAdd.AddInplace(m3, p3);
float flexiblity = 0.6f;
Vector3 centerOfRotation = RandomUtil.Vector3(rnd);
MassMoment massMoment = new MassMoment();
massMoment.AddFlexibleInPlace(momentToAdd, flexiblity, centerOfRotation);
MassMoment expectedMoment = new MassMoment();
expectedMoment.AddInplace((1 - flexiblity) * m1, p1);
expectedMoment.AddInplace((1 - flexiblity) * m2, p2);
expectedMoment.AddInplace((1 - flexiblity) * m3, p3);
expectedMoment.AddInplace(flexiblity * m1, centerOfRotation);
expectedMoment.AddInplace(flexiblity * m2, centerOfRotation);
expectedMoment.AddInplace(flexiblity * m3, centerOfRotation);
PhysicsAssert.AreEqual(massMoment, expectedMoment, Acc);
}
public void TestCenterOfMass()
{
Random rnd = new Random(0);
Vector3 p1 = RandomUtil.Vector3(rnd); float m1 = RandomUtil.PositiveFloat(rnd);
Vector3 p2 = RandomUtil.Vector3(rnd); float m2 = RandomUtil.PositiveFloat(rnd);
Vector3 p3 = RandomUtil.Vector3(rnd); float m3 = RandomUtil.PositiveFloat(rnd);
var accum = new MassMoment();
accum.AddInplace(m1, p1);
accum.AddInplace(m2, p2);
accum.AddInplace(m3, p3);
Vector3 expectedCenterOfMass = (m1 * p1 + m2 * p2 + m3 * p3) / (m1 + m2 + m3);
MathAssert.AreEqual(expectedCenterOfMass, accum.GetCenterOfMass(), Acc);
}
public void TestRotate()
{
Random rnd = new Random(1);
Vector3 p1 = RandomUtil.Vector3(rnd); float m1 = RandomUtil.PositiveFloat(rnd);
Vector3 p2 = RandomUtil.Vector3(rnd); float m2 = RandomUtil.PositiveFloat(rnd);
Vector3 p3 = RandomUtil.Vector3(rnd); float m3 = RandomUtil.PositiveFloat(rnd);
Quaternion rotation = RandomUtil.UnitQuaternion(rnd);
var massMoment = new MassMoment();
var rotatedMassMoment = new MassMoment();
massMoment.AddInplace(m1, p1); rotatedMassMoment.AddInplace(m1, Vector3.Transform(p1, rotation));
massMoment.AddInplace(m2, p2); rotatedMassMoment.AddInplace(m2, Vector3.Transform(p2, rotation));
massMoment.AddInplace(m3, p3); rotatedMassMoment.AddInplace(m3, Vector3.Transform(p3, rotation));
PhysicsAssert.AreEqual(massMoment.Rotate(rotation), rotatedMassMoment, Acc);
}
public void TestTranslate()
{
Random rnd = new Random(1);
Vector3 p1 = RandomUtil.Vector3(rnd); float m1 = RandomUtil.PositiveFloat(rnd);
Vector3 p2 = RandomUtil.Vector3(rnd); float m2 = RandomUtil.PositiveFloat(rnd);
Vector3 p3 = RandomUtil.Vector3(rnd); float m3 = RandomUtil.PositiveFloat(rnd);
Vector3 translation = RandomUtil.Vector3(rnd);
var massMoment = new MassMoment();
var translatedMassMoment = new MassMoment();
massMoment.AddInplace(m1, p1); translatedMassMoment.AddInplace(m1, p1 + translation);
massMoment.AddInplace(m2, p2); translatedMassMoment.AddInplace(m2, p2 + translation);
massMoment.AddInplace(m3, p3); translatedMassMoment.AddInplace(m3, p3 + translation);
PhysicsAssert.AreEqual(massMoment.Translate(translation), translatedMassMoment, Acc);
}
public void TestMomentOfInertia()
{
Random rnd = new Random(1);
Vector3 p1 = RandomUtil.Vector3(rnd); float m1 = RandomUtil.PositiveFloat(rnd);
Vector3 p2 = RandomUtil.Vector3(rnd); float m2 = RandomUtil.PositiveFloat(rnd);
Vector3 p3 = RandomUtil.Vector3(rnd); float m3 = RandomUtil.PositiveFloat(rnd);
var accum = new MassMoment();
accum.AddInplace(m1, p1);
accum.AddInplace(m2, p2);
accum.AddInplace(m3, p3);
Vector3 axisOfRotation = RandomUtil.UnitVector3(rnd);
Vector3 centerOfRotation = RandomUtil.Vector3(rnd);
float expectedMomentOfInertia =
PointMassMomentOfInertia(m1, p1, axisOfRotation, centerOfRotation) +
PointMassMomentOfInertia(m2, p2, axisOfRotation, centerOfRotation) +
PointMassMomentOfInertia(m3, p3, axisOfRotation, centerOfRotation);
Assert.AreEqual(expectedMomentOfInertia, accum.GetMomentOfInertia(axisOfRotation, centerOfRotation), Acc);
}
public void TestAddingMassMoments()
{
Random rnd = new Random(2);
Vector3 p1 = RandomUtil.Vector3(rnd); float m1 = RandomUtil.PositiveFloat(rnd);
Vector3 p2 = RandomUtil.Vector3(rnd); float m2 = RandomUtil.PositiveFloat(rnd);
Vector3 p3 = RandomUtil.Vector3(rnd); float m3 = RandomUtil.PositiveFloat(rnd);
var accumA = new MassMoment();
accumA.AddInplace(m1, p1);
accumA.AddInplace(m2, p2);
accumA.AddInplace(m3, p3);
var accumB = new MassMoment();
accumB.AddInplace(m1, p1);
var accumB2 = new MassMoment();
accumB2.AddInplace(m2, p2);
accumB2.AddInplace(m3, p3);
accumB.AddInplace(accumB2);
PhysicsAssert.AreEqual(accumA, accumB, Acc);
}
