【转帖】control points of splines
 

control points of splines
control points of splines
hi, some problems were caught in this file(as in attatchment). there are 11 splines in the model space. when i read the control points fff"> of those splines, the results are not same as they are showing in autocad r2004.
could you please tell me how can i get the right ones?
thanks
vintonzhang
quote:
originally posted by ziyueban
hi, some problems were caught in this file(as in attatchment). there are 11 splines in the model space. when i read the control points fff"> of those splines, the results are not same as they are showing in autocad r2004.
autocad uses quite sophisticated algorithm to calculate spline's nurbs data when fit tolerance is non-zero - we don't know it yet. btw, i can't see attached file.
sincerely yours,
george udov
the file is here
sorry, the file is here.
many thanks!!!
attached files (238.0 kb, 7 views)


control points are computed incorrectly in this file because start and end tangents of some splines(f.e. one with handle 1dc8) aren't unit-length. this is defect of dwgdirect (we should normalize tangents when reading dwg), it is fixed, fix will be available in next release.
sincerely yours,
george udov