I didnt find any way to fix self intersected polygon in geos. I am finding that a very small percentage of the polygons are self intersecting. The geometry must be simplified before it can be saved to a geodatabase. Simplify method simplifies the given geometry to make it topologically consistent according to their geometry type. For example, if a polygon crosses itself, the polygon will be repaired to become a multipart polygon such that no part crosses any other part, although the polygon will still look self crossing. Checks to see if polygon rings cross each other and indicates if the polygon is self intersecting, which means the ring of the polygon crosses itself. If i use the repair geometry tool, it finds several self intersections and fixes them. If there are no crossing points or there are no lines of overlap, the respective geometry will not be present in the returned collection. Algorithm for decomposing a complex selfintersecting. I have a shapefile containing polygons zm which have self intersecting features. Mapobjects can work with self intersecting polygons, such as a figure8.
Jts seems to offer the behaviour i require, though i had to do a little legwork in my own code. I am attempting to mask a raster to us forest service boundaries in qgis. I have tested it on the following limited set of inputs, and it seems to behave the way i require. There was no adverse effect to these types of geometry therefore the check geometry tool will no longer report the feature as a problem, and the repair geometry tool will no longer perform a fix on the features geometry. Geometry engine simplify sample viewer view sample on github. Geodatabase topology rules and topology error fixes arcgis. Repair self intersection topographic production arcgis pro. Also, sde layers may not store or work with selfintersecting polygons. Also, sde layers may not store or work with self intersecting polygons.
If that line crosses over itself to form a loop, then the left and right polygons get reversed for the portion within the loop. Self intersecting polygons multipart polygons can not overlap within a geometry. Then, i tried to add it as a boundary again, only to get. Arcgis geoprocessing tool that repairs self intersecting line or polygon features. Is it possible to have self intersecting polygons in shapefile. There are some instructions on this page see the heading entitled decompose into simple pieces however my current implementation is falling short see img below while im able to find all the self intersecting points im not able. Is there a way to convert a self intersecting polygon to a. Were importing a whole bunch of arcgis shapefiles into postgis, converted on the fly with shp2pgsql.
How to remove self intersections polygons using fme fme. Fill rule for the polygon that defines the interior of the self intersecting. Area of a selfintersecting polygon free math help forum. Look like i can use geometryogcvalidator to filter out those points.
Its worth to clarify that self intersecting polygon is invalid but according to ogc sfs. Wondering if anyone has run into problems with self intersecting polygons and slivers causing problems in down stream tools. This approach solves a strictly harder problem than just finding an intersection free polygon, though, so maybe a simpler solution is possible. Remove self intersectionshelp documentation arcgis desktop. Im not sure that i did it correctly, but it still didnt work. For the self intersecting case wouldnt it be better to treat the self intersection as an outer boundary and any crossing areas as show boundaries. Then, i selected the polyline manually, and selected simplify objects, modify original object. Incase of a regular polygon we could directly use the formula, but in case of a self intersecting polygon it doesnt quite. Illegal selfintersecting or non closed boundary polyline i always get the message after i make a closed boundary polygon, and i know its a closed boundary, but i know how to fix it. In these cases wed just have to do perform the update manually in arcgis desktop. Problem is, if the shapefiles have any ring self intersections, the import chokes. Arcgis geoprocessing tool that repairs selfintersecting line or polygon features. But when i make an export of this file or a selection of it, this export contains self intersections again.
Click the features from whose intersection you want to create a new feature. If you have feature templates for the layers in your map, click the template button and click the template to use to create the new feature. Requires that the interior of polygons in one feature class or subtype must not overlap with the interior of polygons in another feature class or subtype. The output polygon features are where a polygon from one of the input feature classes or layer intersects a polygon from the other input feature class. While the polygon fill algorithm used in arcgis draw polygons correctly that do not close correctly, the geometries remain invalid. For example, if a polygon crosses itself, the polygon will be repaired to become a multipart polygon such that no part crosses any other part, although the polygon will still look selfcrossing. For instance, lets say we have a self intersecting 4gon quadrilateral that looks like an hourglass. Srinivas, and almasi does not handle selfintersecting polygons, is not. Simplify a polygon with a self intersecting geometry. Illegal selfintersecting or non closed boundary polygon. Imagine an extent that contains 10 polygons, 1 of which is self intersecting.
The graphic below illustrates the result of intersecting two polygon feature classes with the output type parameter set to point. The output line features are where a polygon from one of the input feature classes share a common boundary intersect at a line with a polygon from the other input feature class. It is a valid complex polygon in the world of geometry. For instance, it rectifies polygons that may be self intersecting, or contain incorrect ring orientations. Illegal selfintersecting or nonclosed boundary polyline. How to detect or bypass selfintersecting poly boundary. The graphic below illustrates the result of intersecting two polygon feature classes with the output type parameter set to either poly or the default lowest. Remove self intersectionshelp documentation arcgis. How to remove self intersections polygons using fme. All four boolean clipping operations are supported intersection, union, difference and exclusiveor.
Coverage, dissolve, feature to line, feature to polygon, integrate, or validatetopology. Since its been some time since the last update, some may be wondering if i no longer plan further updates. Illegal selfintersecting or non closed boundary polygon after isolating i ended up weeding the feature many times to get rid of a lot of vertices. Contains self intersecting paths applicable only to polyline featuresa polyline must not intersect itself. The graphic below illustrates the result of intersecting two polygon feature classes with the output type parameter set to line. This rule is used when an area cannot belong to two separate feature classes. Illegal selfintersecting or non closed boundary polygon when i use lans desktop 2006, if boundary is self intersecting, there was a small green x symbol appears on polyline. Illegal selfintersecting boundary polygon autodesk. Polygons of the two feature classes can share edges or vertices or be completely disjointed. Uses the free and open source software library clipper created by angus johnson.
The esri geometry api for java enables developers to write custom applications for. The desktop gis software typically takes hours to perform overlay for. Arcinfo and arcgis cannot create these types of geometries. Ive been attempting to write a bentleyottmann sweepline algorithm to transform a self intersecting complex into a set of simple polygons. Mapobjects can work with selfintersecting polygons, such as a figure8. It just bugs me sometimes when the message pops up when i add it as a. Polygon object, whose layout is determined completely by a series of points. A user may draw a polygon which is self intersecting or contains incorrect ring orientations. I need to determine if this polygon is self intersecting. When i make my service call through flex, i get back a 200 message w a. The portion between the feature and the intersection points are either deleted or split into a new feature. The original features are maintained, and the new feature is created without attribute values in the current layer.
How to remove self intersections using fme i wonder if there is a method to repair the self intersections in the fme such as the arcgis. Overlapping polygons can be resolved by the topology rule must not overlap. Seems to me most of those self intersecting errors were just tolerance issue and i have no problem create a polygon from them using arcgis desktop. The last vertex of a polygon ring should be the same as the last vertex. The validate function i wrote breaks down a polygon multipolygon into a collection of non self intersecting linestrings, and then uses the polygonizer class to build polygons from the result. Creates a new instance of this class and initializes it with values from a json object generated from a product in the arcgis. The clipper library performs clipping and offsetting for both lines and polygons. Once properly established, delete the original polygon. You can create a new feature from the intersection of features of different layers, but the layers must be of the same geometry type either line or polygon. Can we take every self intersecting polygon and, ignoring the angles, form a simple non self intersecting polygon with the same side lengths as the self intersecting polygon and with side lengths that remain in the same order. The list still shows polygon 1 being on the left and polygon 2 being on the right, even though that is not the case within the loop. Self intersecting features, such as lines and polygons. Polygons can be of any shape including self intersecting polygons. Tool polygon selfintersection sagagis tool library.
Selfintersecting polygons and simple polygons math forums. Illegal selfintersecting or nonclosed boundary polygon. Is there anyway to get it to work by means of any preprocessing or transformations on the polygon structure to obtain the area without having to divide the polygon into a set of triangles and then summing up the area of the. The output polygon features are where a polygon from one of the input feature classes or layer intersects a polygon from the other input feature class or layer. Sort a list of points to form a nonselfintersecting polygon. Gis vector data for example shapefile contains polygonal data. Efficient parallel and distributed algorithms for gis polygon overlay. Choose the target in which the new feature will be created. The portion between the feature and the intersection points are either deleted or.