[mapguide-trac] #994: 3D features containing invalid (null) Z values are not always displayed correctly in 2D

[MapGuide Open Source]

#994: 3D features containing invalid (null) Z values are not always displayed
correctly in 2D
------------------------------+---------------------------------------------
   Reporter:  waltweltonlair  |       Owner:  waltweltonlair
       Type:  defect          |      Status:  new           
   Priority:  medium          |   Milestone:  2.1           
  Component:  General         |     Version:  2.1.0         
   Severity:  minor           |    Keywords:                
External_id:  1206094.02      |  
------------------------------+---------------------------------------------
 It's possible for users to create 3D features that have points with null Z
 values.  Oracle, for example, allows you to store such data even though
 technically it's invalid.  When FDO reads these points the invalid Z's
 come back as large values (-1.25e126).  For regular polylines / polygons,
 these spurious Z values don't impact their display in 2D - z's are
 ignored.  But if the points are part of an arc segment then it will impact
 the 2D display.  That's because 3D arcs are tessellated in the plane of
 the arc (the plane defined by its three 3D points), and the resulting
 tessellated points are projected back into the 2D space.  So if one or
 more of the arc's z-values is bad (-1.25e126) it will affect the
 tessellation and corrupt the display.

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Ticket URL: <https://trac.osgeo.org/mapguide/ticket/994>
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