public void SphereMass()
{
var s = new SphereShape(2);
float m0;
Vector3F com0;
Matrix33F i0;
MassHelper.GetMass(s, new Vector3F(1, -2, -3), 1, true, 0.001f, 10, out m0, out com0, out i0);
var m = s.GetMesh(0.001f, 10);
m.Transform(Matrix44F.CreateScale(1, -2, -3));
float m1;
Vector3F com1;
Matrix33F i1;
MassHelper.GetMass(m, out m1, out com1, out i1);
const float e = 0.01f;
Assert.IsTrue(Numeric.AreEqual(m0, m1, e * (1 + m0)));
Assert.IsTrue(Vector3F.AreNumericallyEqual(com0, com1, e * (1 + com0.Length)));
Assert.IsTrue(Matrix33F.AreNumericallyEqual(i0, i1, e * (1 + i0.Trace)));
// Try other density.
float m2;
Vector3F com2;
Matrix33F i2;
MassHelper.GetMass(s, new Vector3F(1, -2, -3), 0.7f, true, 0.001f, 10, out m2, out com2, out i2);
Assert.IsTrue(Numeric.AreEqual(m0 * 0.7f, m2, e * (1 + m0)));
Assert.IsTrue(Vector3F.AreNumericallyEqual(com0, com2, e * (1 + com0.Length)));
Assert.IsTrue(Matrix33F.AreNumericallyEqual(i0 * 0.7f, i2, e * (1 + i0.Trace)));
// Try with target mass.
float m3;
Vector3F com3;
Matrix33F i3;
MassHelper.GetMass(s, new Vector3F(1, -2, -3), 23, false, 0.001f, 10, out m3, out com3, out i3);
Assert.IsTrue(Numeric.AreEqual(23, m3, e * (1 + m0)));
Assert.IsTrue(Vector3F.AreNumericallyEqual(com0, com3, e * (1 + com0.Length)));
Assert.IsTrue(Matrix33F.AreNumericallyEqual(i0 * 23 / m0, i3, e * (1 + i0.Trace)));
}
public void ReverseWindingOrder()
{
SphereShape sphere = new SphereShape(1);
var mesh = sphere.GetMesh(0.1f, 3);
var clone = mesh.Clone();
clone.ReverseWindingOrder();
// Test if all normal are inverted.
for (int i = 0; i < mesh.NumberOfTriangles; i++)
{
var n0 = mesh.GetTriangle(i).Normal;
var n1 = clone.GetTriangle(i).Normal;
Assert.IsTrue(Vector3F.AreNumericallyEqual(n0, -n1));
}
}
public void SphereTest()
{
var s = new SphereShape(1);
var v0 = s.GetVolume(0.001f, 10);
var m = s.GetMesh(0.001f, 10);
var v1 = m.GetVolume();
Assert.IsTrue(Numeric.AreEqual(v0, v1, 0.01f * (1 + v0))); // 1% error is allowed.
}
