http://www.zwsoft.com/forum/viewthread.php?tid=2333 [align=left]Hi[/align] [align=left]am trying to loft a series of closed 2d polyline cross sections to create a landscape solid or surface.[/align] [align=left]It will do 5 but selecting anymore causes it to say the "selected entities are not valid".[/align] [align=left]this is the link to the autodesk article [/align][url=http://usa.autodesk.com/adsk/servlet/ps/item?siteID=123112&id=7804217&linkID=9240617]http://usa.autodesk.com/adsk/servlet...linkID=9240617[/url] [align=left]but I'm having trouble understanding it. I tried opening all the polylines but that just didn't work.[/align] [align=left]I've tried revsersing the selection order but no go either.[/align] [align=left]I will have a go at planesurf but really I was hoping to loft a solid.[/align] [align=left]Any suggestions?[/align] [align=left]I'll try and post the file but it's pretty big.[/align] Blackfish 2012-07-23 17:43:17 http://www.zwsoft.com/forum/viewthread.php?tid=2333&pid=15544 I would try doing 5 at a time. If if works then boost this to 10 at a time. I think the fit will be OK. RobDraw 2012-07-23 17:45:01