[
https://issues.apache.org/jira/browse/LUCENE-7970?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16175752#comment-16175752
]
Karl Wright commented on LUCENE-7970:
-------------------------------------
My initial observations:
(1) The "inner" and "outer" planes are in fact parallel to one another -- so we
would want to compute first the one that goes through the upper latitude point
and the lower latitude point, and then compute an "adjusted" parallel plane.
The problem is how to figure out the adjustment. This is what I still need to
consider. One way to do it is to find a point-on-bearing to the left or right
and pick the second plane's D coefficient based on that point. I think this
would work quite well actually.
(2) The choice of which plane is "inner" and which plane is "outer" depends on
whether c > ab, and on whether the radius of the circle is greater than 180
degrees. Need to think this through too.
> Improve generation of circle plane
> -----------------------------------
>
> Key: LUCENE-7970
> URL: https://issues.apache.org/jira/browse/LUCENE-7970
> Project: Lucene - Core
> Issue Type: Improvement
> Components: modules/spatial3d
> Reporter: Ignacio Vera
> Assignee: Karl Wright
> Attachments: LUCENE_7970.patch, LUCENE-7970.patch,
> LUCENE-7970-proposed.patch
>
>
> Hi [~Karl wright],
> How circles are currently build do not behave very well when the planet model
> is not an sphere. when you are close to the border in WGS84 you might get
> false positves or false negatives when checking if a point is WITHIN. I think
> the reason is how the points to generate the circle plane are generated which
> assumes a sphere.
> My proposal is the following:
> Add a new method to PlanetModel:
> public GeoPoint pointOnBearing(GeoPoint from, double dist, double bearing);
> Which uses and algorithm that takes into account that the planet might not be
> spherical. For example Vincenty's formulae
> (https://en.wikipedia.org/wiki/Vincenty%27s_formulae).
> Use this method to generate the points for the circle plane. My experiments
> shows that this approach removes false negatives in WGS84 meanwhile it works
> nicely in the Sphere.
> Does it make sense?
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org
For additional commands, e-mail: dev-h...@lucene.apache.org
