public void IsValidTest()
{
var m = Matrix44F.CreateTranslation(1, 2, 3) * Matrix44F.CreateRotationY(0.1f) * Matrix44F.CreateScale(-2, 3, 4);
Assert.IsTrue(SrtTransform.IsValid(m));
// Concatenating to SRTs creates a skew.
m = Matrix44F.CreateRotationZ(0.1f) * Matrix44F.CreateScale(-2, 3, 4) * m;
Assert.IsFalse(SrtTransform.IsValid(m));
}
public void FromToMatrixTest()
{
var t = new Vector3F(1, 2, 3);
var r = new QuaternionF(1, 2, 3, 4).Normalized;
var s = new Vector3F(2, 7, 9);
var m = Matrix44F.CreateTranslation(t) * Matrix44F.CreateRotation(r) * Matrix44F.CreateScale(s);
var srt = SrtTransform.FromMatrix(m);
Assert.IsTrue(Vector3F.AreNumericallyEqual(t, srt.Translation));
Assert.IsTrue(QuaternionF.AreNumericallyEqual(r, srt.Rotation));
Assert.IsTrue(Vector3F.AreNumericallyEqual(s, srt.Scale));
// XNA:
srt = SrtTransform.FromMatrix((Matrix)m);
Assert.IsTrue(Vector3F.AreNumericallyEqual(t, srt.Translation));
Assert.IsTrue(QuaternionF.AreNumericallyEqual(r, srt.Rotation));
Assert.IsTrue(Vector3F.AreNumericallyEqual(s, srt.Scale));
// With negative scale, the decomposition is not unique (many possible combinations of
// axis mirroring + rotation).
t = new Vector3F(1, 2, 3);
r = new QuaternionF(1, 2, 3, 4).Normalized;
s = new Vector3F(2, -7, 9);
m = Matrix44F.CreateTranslation(t) * Matrix44F.CreateRotation(r) * Matrix44F.CreateScale(s);
srt = SrtTransform.FromMatrix(m);
var m2 = (Matrix44F)srt;
Assert.IsTrue(Matrix44F.AreNumericallyEqual(m, m2));
m2 = srt.ToMatrix44F();
Assert.IsTrue(Matrix44F.AreNumericallyEqual(m, m2));
m2 = srt;
Assert.IsTrue(Matrix44F.AreNumericallyEqual(m, m2));
Matrix mXna = srt.ToXna();
Assert.IsTrue(Matrix44F.AreNumericallyEqual(m, (Matrix44F)mXna));
mXna = srt;
Assert.IsTrue(Matrix44F.AreNumericallyEqual(m, (Matrix44F)mXna));
}
private void UpdateCamera(CameraNode camera)
{
// Camera distance from CameraTarget.
float distance = (camera.PoseWorld.Position - CameraTarget).Length;
// Re-orthogonalize to remove numerical errors which could add up.
var minor = _transform.Minor;
minor.Orthogonalize();
_transform.Minor = minor;
// Create view matrix for look at origin (ignoring CameraTarget).
camera.View = Matrix44F.CreateTranslation(0, 0, -distance) * _transform;
// Apply translation to look at CameraTarget.
var pose = camera.PoseWorld;
pose.Position += CameraTarget;
camera.PoseWorld = pose;
}