[
https://issues.apache.org/jira/browse/LUCENE-8276?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16452220#comment-16452220
]
Karl Wright commented on LUCENE-8276:
-------------------------------------
[~ivera], since we basically need to draw a path from the test point to the
check point, we can short-circuit the path by noticing that the check point and
the test point are the same. But that says nothing at all about the antipodes
of the test point. We do not know if that point is in set or out of set. This
is very different from the assumptions about poles made in GeoPolygonFactory.
If you are having trouble building a traversal plane, it means that you have
chosen the wrong kind of iterator to construct. There are three kinds:
SectorLinear (which is < 180 degrees), FullLinear (180 degrees), and Dual
(where each leg is < 180 degrees).
> GeoComplexPolygon failures
> --------------------------
>
> Key: LUCENE-8276
> URL: https://issues.apache.org/jira/browse/LUCENE-8276
> Project: Lucene - Core
> Issue Type: Bug
> Components: modules/spatial3d
> Reporter: Ignacio Vera
> Assignee: Ignacio Vera
> Priority: Major
> Attachments: LUCENE-XXXX-test.patch, LUCENE-XXXX.patch,
> LUCENE_XXXX_random.patch
>
>
> I have tightened a bit more the random test for polygons and
> GeoComplexPolygons still shows issues when traveling planes that are cutting
> the world near the pole. I could identify three cases:
>
> case 1) It happens when the check point is on aone of the test point planes
> but the planes is close to the pole and cannot be traversed. In that case we
> hit the following part of the code:
> {code:java}
> } else if (testPointFixedYPlane.evaluateIsZero(x, y, z) ||
> testPointFixedXPlane.evaluateIsZero(x, y, z) ||
> testPointFixedZPlane.evaluateIsZero(x, y, z)) {
> throw new IllegalArgumentException("Can't compute isWithin for specified
> point");
> } else {{code}
>
> It seems this check is unnecesary. If removed then a traversal is choosen and
> evrything works as expected.
>
> case 2) In this case a {{DualCrossingEdgeIterator}} is used with one of the
> planes being close to the pole but inside current restricutions (is a valid
> traversal). I think the problem happens when computing the intersection
> points for above and below plane in {{computeInsideOutside}}:
> {code:java}
> final GeoPoint[] outsideOutsidePoints =
> testPointOutsidePlane.findIntersections(planetModel, travelOutsidePlane);
> //these don't add anything: , checkPointCutoffPlane, testPointCutoffPlane);
> final GeoPoint outsideOutsidePoint =
> pickProximate(outsideOutsidePoints);{code}
> The intersection above results in two points close to each other and close to
> the intersection point, and therefore {{pickProximate}} fails in choosing the
> right one.
> case 3) In this case a {{LinearCrossingEdgeIterator}} is used with the plane
> being close to the pole. In this case when evaluating the intersection
> between an edge and the plane, we get two intersections (because are very
> close together) inside the bounds instead of one. The result is too many
> crossings.
>
> After evaluating this errors I think we should really prevent using planes
> that are near a pole. I attached a new version of {{GeoComplexPolygon}} that
> seems to solve this issues. The approach is the following:
> {{NEAR_EDGE_CUTOFF}} is not expressed as a linear distance but as a
> percentage, curerntly 0.75 . If ab is the value of a semiaxis, the logic
> disallows to travel a plane if the distance between the plane and the center
> of the world is bigger that {{NEAR_EDGE_CUTOFF}} * pole.
>
>
>
>
>
>
>
>
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
