【转帖】how can calculate tangent vector in oddbspline 9with fitpoin
 

how can calculate tangent vector in oddbspline (with fitpoin
how can calculate tangent vector in oddbspline (with fitpoints) ?
hi, i'm david lee, korean.
in autocad program, when i draw a spline with fitpoint, i use the close option. in this case, tangent vector is created automatically.
could i get tangent vector dwgdirect? (setclosed option?)
please help me.

hi, david.
yes, you can do it by oddbspline::getfirstderiv function.
sincerely yours,
george udov