/// <summary>
/// Gets the rotation matrix from the normal vector (extrusion direction) of an entity.
/// </summary>
/// <param name="zAxis">Normal vector.</param>
/// <returns>Rotation matrix.</returns>
public static Matrix3 ArbitraryAxis(Vector3 zAxis)
{
zAxis.Normalize();
if (zAxis.Equals(Vector3.UnitZ))
{
return(Matrix3.Identity);
}
Vector3 wY = Vector3.UnitY;
Vector3 wZ = Vector3.UnitZ;
Vector3 aX;
if ((Math.Abs(zAxis.X) < 1 / 64.0) && (Math.Abs(zAxis.Y) < 1 / 64.0))
{
aX = Vector3.CrossProduct(wY, zAxis);
}
else
{
aX = Vector3.CrossProduct(wZ, zAxis);
}
aX.Normalize();
Vector3 aY = Vector3.CrossProduct(zAxis, aX);
aY.Normalize();
return(new Matrix3(aX.X, aY.X, zAxis.X, aX.Y, aY.Y, zAxis.Y, aX.Z, aY.Z, zAxis.Z));
}
public static void OffsetLine(Vector3 start, Vector3 end, Vector3 normal, double offset, out Vector3 newStart, out Vector3 newEnd)
{
Vector3 dir = end - start;
dir.Normalize();
Vector3 perp = Vector3.CrossProduct(normal, dir);
newStart = start + perp * offset;
newEnd = end + perp * offset;
}