[
https://issues.apache.org/jira/browse/GEOMETRY-59?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16889731#comment-16889731
]
Dirk Bonekämper commented on GEOMETRY-59:
-----------------------------------------
I think [~mattjuntunen]s analysis is right on the money. He also mentioned that
there is one correct orientation for the generated plane, which is the
orientation of the facet as a whole.
So, if we can find 3 vertices that have the same orientation as the facet, we
can solve the problem. Let me start with a statement:
Any vertex that is on the the convex hull of the facet, together with it's
adjacent vertices, forms a triplet that has the same orientation as the facet.
( [https://en.wikipedia.org/wiki/Curve_orientation)]
So if we can find one point that's guaranteed to be on the convex hull, we're
set. Mentioned in the article is method to do this without constructing the
full hull.
# Select the vertex with the smallest x coordinate.
# If there is more than one vertex with the same x, select the one with the
lowest y coordinate.
# If there is more than one vertex with the same xy, select the one with the
lowest z coordinate.
I do have a proof of concept implementation that seems to work. I'll try to
make a pull request ASAP.
> unexpected output from PolyhedronsSet::checkPoint
> -------------------------------------------------
>
> Key: GEOMETRY-59
> URL: https://issues.apache.org/jira/browse/GEOMETRY-59
> Project: Apache Commons Geometry
> Issue Type: Bug
> Components: Euclidean 3D
> Reporter: Dirk Bonekämper
> Priority: Major
> Attachments: InsideProblemTest.java
>
>
> In my project I'm working with 3D Regions modeled as prisms. The base
> polygons are mostly concave. I got wrong results and boiled it down to the
> attached unit test. It creates a prism with a concave base. A point that is
> above the prism gets classified as INSIDE.
--
This message was sent by Atlassian JIRA
(v7.6.14#76016)
