/// <summary>
/// Create a transform centered at origin with its Z axis pointing
/// along up.
/// </summary>
/// <param name="origin">The origin of the transform.</param>
/// <param name="z">The vector which will define the Z axis of the transform.</param>
/// <param name="rotation">An optional rotation around the z axis.</param>
public Transform(Vector3 origin, Vector3 z, double rotation = 0.0)
{
Vector3 x = Vector3.XAxis;
Vector3 y = Vector3.YAxis;
if (!z.IsParallelTo(Vector3.ZAxis))
{
// Project up onto the ortho plane
var p = new Plane(origin, z);
var test = Vector3.ZAxis.Project(p);
x = test.Cross(z).Unitized();
y = x.Cross(z.Negate()).Unitized();
}
else
{
// Ensure that we have a right-handed coordinate system.
if (z.Dot(Vector3.ZAxis).ApproximatelyEquals(-1))
{
y = Vector3.YAxis.Negate();
}
}
this.Matrix = new Matrix(x, y, z, Vector3.Origin);
ApplyRotationAndTranslation(rotation, z, origin);
}
/// <summary>
/// Create a transform centered at origin with its Z axis pointing
/// along up.
/// </summary>
/// <param name="origin">The origin of the transform.</param>
/// <param name="z">The vector which will define the Z axis of the transform.</param>
/// <param name="rotation">An optional rotation around the z axis.</param>
public Transform(Vector3 origin, Vector3 z, double rotation = 0.0)
{
Vector3 x = Vector3.XAxis;
Vector3 y = Vector3.YAxis;
if (!z.IsParallelTo(Vector3.ZAxis))
{
// Project up onto the ortho plane
var p = new Plane(origin, z);
var test = Vector3.ZAxis.Project(p);
x = test.Cross(z).Unitized();
y = x.Cross(z.Negate()).Unitized();
}
this.Matrix = new Matrix(x, y, z, Vector3.Origin);
ApplyRotationAndTranslation(rotation, z, origin);
}