topic Re: converting polygons to lines flips direction in Data Management Questions https://community.esri.com/t5/data-management-questions/converting-polygons-to-lines-flips-direction/m-p/497118#M28227 <HTML><HEAD></HEAD><BODY><SPAN>Jarek,</SPAN><BR /><BR /><SPAN>I think its to do with correct topology of the polygon. If you look at the Help on the </SPAN><A href="http://webhelp.esri.com/arcgisdesktop/9.2/index.cfm?TopicName=check_geometry_(data_management)">Check Geometry</A><SPAN> tool it mentions what direction an outer ring a polygon should be. I guess when you copy the polygon into the polyline featureclass ArcMap is enforcing correct topology for the polygon and consequently your polyline ends up clockwise. Well thats my guess of whats going on...</SPAN><BR /><BR /><SPAN>Duncan</SPAN></BODY></HTML> Fri, 13 Jan 2012 21:35:13 GMT DuncanHornby 2012-01-13T21:35:13Z converting polygons to lines flips direction https://community.esri.com/t5/data-management-questions/converting-polygons-to-lines-flips-direction/m-p/497117#M28226 <HTML><HEAD></HEAD><BODY><SPAN>Hi All,</SPAN><BR /><BR /><SPAN>What I want to ask about is not really an issue but I would like to understand why such thing happens.</SPAN><BR /><BR /><SPAN>I'm using ArcGIS Desktop 10.0 SP3. I have two shapefiles: polygons and polylines. Both added to ArcMap as single layer each. Imagine I digitize two not complicated polygons. One I digitize clockwise, the other one anti-clockwise. Then I select, copy and paste them to polyline shapefile which essentially means converting them to polylines. </SPAN><BR /><BR /><SPAN>Why the direction of both polylines is like they have been digitized clockwise?</SPAN><BR /><BR /><SPAN>I mentioned the first "clockwise polygon" only to emphasize that it's not a random thing and they're not getting "flipped" - just those polygons digitized in anti-clockwise manor. Why is that?</SPAN><BR /><BR /><SPAN>Regards,</SPAN><BR /><SPAN>Jarek</SPAN></BODY></HTML> Fri, 13 Jan 2012 19:16:10 GMT https://community.esri.com/t5/data-management-questions/converting-polygons-to-lines-flips-direction/m-p/497117#M28226 JaroslawSobanski 2012-01-13T19:16:10Z Re: converting polygons to lines flips direction https://community.esri.com/t5/data-management-questions/converting-polygons-to-lines-flips-direction/m-p/497118#M28227 <HTML><HEAD></HEAD><BODY><SPAN>Jarek,</SPAN><BR /><BR /><SPAN>I think its to do with correct topology of the polygon. If you look at the Help on the </SPAN><A href="http://webhelp.esri.com/arcgisdesktop/9.2/index.cfm?TopicName=check_geometry_(data_management)">Check Geometry</A><SPAN> tool it mentions what direction an outer ring a polygon should be. I guess when you copy the polygon into the polyline featureclass ArcMap is enforcing correct topology for the polygon and consequently your polyline ends up clockwise. Well thats my guess of whats going on...</SPAN><BR /><BR /><SPAN>Duncan</SPAN></BODY></HTML> Fri, 13 Jan 2012 21:35:13 GMT https://community.esri.com/t5/data-management-questions/converting-polygons-to-lines-flips-direction/m-p/497118#M28227 DuncanHornby 2012-01-13T21:35:13Z Re: converting polygons to lines flips direction https://community.esri.com/t5/data-management-questions/converting-polygons-to-lines-flips-direction/m-p/497119#M28228 <HTML><HEAD></HEAD><BODY><SPAN>Duncan,</SPAN><BR /><BR /><SPAN>Thank you for your response.</SPAN><BR /><BR /><SPAN>I just realised that polygons get converted to that correct form right after I finish drawing them. Same with inner rings. So it has nothing to do with converting them to polylines. </SPAN><BR /><BR /><SPAN>Regards</SPAN><BR /><SPAN>Jarek</SPAN></BODY></HTML> Mon, 16 Jan 2012 06:57:29 GMT https://community.esri.com/t5/data-management-questions/converting-polygons-to-lines-flips-direction/m-p/497119#M28228 JaroslawSobanski 2012-01-16T06:57:29Z Re: converting polygons to lines flips direction https://community.esri.com/t5/data-management-questions/converting-polygons-to-lines-flips-direction/m-p/497120#M28229 <HTML><HEAD></HEAD><BODY><SPAN>The counter-clockwise "ring" is reserved for polygon holes or "inner rings". When you digitize only one ring to finish a polygon, it is automatically considered as the outer ring and corrected to be clockwise.</SPAN></BODY></HTML> Tue, 17 Jan 2012 16:23:48 GMT https://community.esri.com/t5/data-management-questions/converting-polygons-to-lines-flips-direction/m-p/497120#M28229 DanLee 2012-01-17T16:23:48Z