Jan

I've found the problem. Even though the documentation says UNION operations can be performed on one set or both sets of polygons, but all other boolean operations require both sets of polygons to derive meaningful solutions. https://sourceforge.net/p/jsclipper/wiki/documentation/#clipperlibpolytype you really need both subject and clip sets. So, the fix was to add the second polygon as ptClip and then the union works correctly

Hi Timo, thanks for responding so quickly. You're right it's something weird in the demo. However, I'm still facing the issue in my actual code. I've tried to simplify the paths. To reproduce, copy this in to starter_offset.html: var p1 = [[{"X":703,"Y":594},{"X":703,"Y":719},{"X":827,"Y":1960}]]; var p2 = [[{"X":827,"Y":2029},{"X":827,"Y":2098},{"X":1199,"Y":3015}]]; ClipperLib.JS.ScaleUpPaths(p1, 5); ClipperLib.JS.ScaleUpPaths(p2, 5); var co = new ClipperLib.ClipperOffset(2, 0.25); co.AddPaths(p1,...

On the other hand I can't reproduce it in the c# version of the library: If I replace contents of GenerateRandomPolygon with var subj = new Polygon(new IntPoint[] {new IntPoint(10000, 10000), new IntPoint(20000, 10000), new IntPoint(17000, 15000), new IntPoint(10000, 4000), new IntPoint(12000, 4000), new IntPoint(19000, 15000)}); var co = new ClipperOffset(); co.AddPath(subj, JoinType.jtRound, EndType.etOpenRound); co.Execute(ref subjects, 400); (crude, I know) It doesn't do anything strange when...

Union problem