GeoEvent Intersector between two lines generating null geometries

Question

I have a GeoEvent service polling ArcGIS Server for line features. The inputs are filtered by testing for the intersection against a line geofence. The filtering logic works correctly and only intersecting geoevents are passed to the intersector processor. I'm hoping the intersector will generate a point geometry representing the point of intersection between the line geoevent and the line geofence.

Despite the filter positively identifying an intersection between the geoevent and geofence, the intersector issues a warning in the logs indicating the intersection between the two geomteries is null. Any suggestions on how to configure the intersector to generate a point geometry between two lines would be greatly appreciated.

RJSunderman · Answer

John -

I wanted to update you to let you know that enhancements are being rolled into the 10.5 release for the Intersector processor. At 10.4.x the assumption was that the output geometry would be the same dimension as the event's geometry. That's why the illustration in the product introduction tutorial worked and showed the intersection of an event's polyline with a polygon GeoFence output as a polyline.

Beginning with the 10.5 release, you will be able to configure an Intersector processor to output a specified 'Output Geometry Type'. So, in your case, if you are processing an event with an associated polyline geometry and you want to obtain the point at which your event's polyline intersects a polyline GeoFence - you will be able to do that.

Illustrated below are a couple of the use cases I've used to verify the enhancements to the Intersector processor at 10.5

You'll notice that you can still obtain a multipart polyline when an event's polyline intersects a polygon GeoFence at two separate line segments. You can also get the point intersection between two polylines.

There are several other test cases which I will try to lay out in a blog, which will serve as the documentation for the enhancements to the Intersector processor.

Hope you find the 10.5 enhancements useful -

RJ

RJSunderman · Answer

John -

My apologies that your post from December went so long without a response.

I've reproduced the behavior you describe above in the 10.4 product release. For input, I chose to poll a feature service's polyline feature layer and published a GeoEvent Service whose Intersector spatial processor should have generated a Geometry representing the intersection with polyline features I had imported as GeoFences.

I can obtain the expected results from the Intersector processor when the GeoFences are polygons and the received event's Geometry is one order lower (a polyline) as illustrated in the product introduction tutorial. However, I believe what you're trying to do is supposed to work.

I've submitted a bug for the developer to investigate.

- RJ