Arcs convert to curves when offset.
-
I find this little quirk a bit bothersome when it comes to locating arc centerpoints. If you have an original arc and offset it, the entity that's created is not an arc, but rather a curve. Curves have no 'radius' value under 'entity info' and show no option for arc centerpoint when right clicking the curve entity. Is there anyway to avoid this substitution of arcs to curves when offsetting. I understand that arcs require all segments to be equal, and that when offset, the end segments change and are no longer equal length segments with the rest of the arc. Does anyone have a curve centerpoint suggestion?
-
Try the arc centerpoint ruby.
http://www.scriptspot.com/files/arc_centerpoint.rb
That will help you establish the centerpoint and a reference. Then you can use the arcs ruby with the center and two points option.
-
This is due to the segmented nature of arcs in SU. When you offset a SU arc, the result is strictly speaking no longer an arc, because the endpoints of all the segments are no longer on the same arc, as the start and end segments of an offset arch are shorter. Arcs and circles in SU are determined by the vertex points of the segments, whereas the offset command is offsetting the segment lines. Note too that if you offset a circle by, say, 1 meter, the distance between corresponding points on the two circles will be more than 1 m, whereas the parallel distance between two corresponding segments will be 1 m...
Anssi
Advertisement