【转帖】pline variable width arc segmen
 

pline variable width arc segment
pline variable width arc segment
i am having difficulty creating curves of variable with from a pline arc segment.
i have attempted to analyze the information i receive from pline - the odgecircarc data plus the width information - to build an arc of variable width, but i have not been successful.
i think that the circumference of the variable width arc is composed of two nurbs (not all arcs of variable width can be constructed with ellipses ) connected at each end by two lines of start width and end width respectively.
otherwise, is it possible that the pline is contructed with piece-wise elliptic arc segments?
in short, what steps does the dwg tesselator take with the given data to produce the variable width arcs.
thanks
pline can't contain elliptic arc segments but it's projection on view plane can if view direction is not parallel to pline's normal.
dd tesselator approximates arc segment with polyline, calculates width at each point and using this width and arc radius vector calculates borders of segment.
sergey slezkin