topic Re: Polygon from IPointCollection in ArcObjects SDK Questions https://community.esri.com/t5/arcobjects-sdk-questions/polygon-from-ipointcollection/m-p/518130#M13980 <HTML><HEAD></HEAD><BODY><SPAN>all lines in a polygon must define either an outer or an inner ring.&nbsp; The red line defines neither and is therefor removed during simplify.&nbsp; An easy way to see if it will work is to try it in ArcMap.&nbsp; Make a polygon that snaps back to itself in two consecutive vertices like your diagram.&nbsp; The result is a straight donut polygon.&nbsp; I think the only way to make something that looks like what you have is to introduce a small gap at position X.</SPAN></BODY></HTML> Thu, 27 May 2010 14:19:04 GMT AlexanderGray 2010-05-27T14:19:04Z Polygon from IPointCollection https://community.esri.com/t5/arcobjects-sdk-questions/polygon-from-ipointcollection/m-p/518129#M13979 <HTML><HEAD></HEAD><BODY><SPAN>Hello</SPAN><BR /><BR /><SPAN>I have a query regarding the creation of a polygon from an IPointCollection (see attached).</SPAN><BR /><BR /><SPAN>I have 2 IPolylines (A and B) that are closed circles.&nbsp; A is created via ConstructOffset of B.&nbsp; Both A and B have IPointCollections that start and finish at X and vertices that travel in a clockwise direction.</SPAN><BR /><BR /><SPAN>My aim is to create a polygon out of these two lines by the insertion of the red line at C.</SPAN><BR /><BR /><SPAN>My thinking is that the vertices in boundary of the new Polygon should start at X and travel clockwise around A, back to X.&nbsp; Then down the red line and anticlockwise around B until reaching the redline and back up to X.</SPAN><BR /><BR /><SPAN>I have reversed the orientation of the vertices in IPointCollection B and added both A and B IPointCollections to a new Polygon point collection.</SPAN><BR /><BR /><SPAN>However I get a solid donut polygon with a hole, the red line seems to be ignored.</SPAN><BR /><BR /><SPAN>Any assistance appreciated...</SPAN><BR /><BR /><SPAN>Nigel</SPAN></BODY></HTML> Thu, 27 May 2010 13:58:31 GMT https://community.esri.com/t5/arcobjects-sdk-questions/polygon-from-ipointcollection/m-p/518129#M13979 NigelTait 2010-05-27T13:58:31Z Re: Polygon from IPointCollection https://community.esri.com/t5/arcobjects-sdk-questions/polygon-from-ipointcollection/m-p/518130#M13980 <HTML><HEAD></HEAD><BODY><SPAN>all lines in a polygon must define either an outer or an inner ring.&nbsp; The red line defines neither and is therefor removed during simplify.&nbsp; An easy way to see if it will work is to try it in ArcMap.&nbsp; Make a polygon that snaps back to itself in two consecutive vertices like your diagram.&nbsp; The result is a straight donut polygon.&nbsp; I think the only way to make something that looks like what you have is to introduce a small gap at position X.</SPAN></BODY></HTML> Thu, 27 May 2010 14:19:04 GMT https://community.esri.com/t5/arcobjects-sdk-questions/polygon-from-ipointcollection/m-p/518130#M13980 AlexanderGray 2010-05-27T14:19:04Z