Hello,

I have 4 points in UTM coordinate system (UTM Zone 33, Northern Hemisphere).These four (the first and the last one are the same):

549340.837580, 5155906.01505, 12.1631324421

549352.704610, 5155906.62361, 5.94776381969

549348.444651, 5155914.53497, 0.0

549340.837580, 5155906.01505, 12.1631324421

I create a closed polygon (triangle) from those 4 points. The shapefile has only this one polygon.

Then reproject the shapefile to WGS84, and save it.

Attached is here: shapefile_polygonZ.zip (925 Bytes)

Shapefile type is MapWinGIS.ShpfileType.SHP_POLYGONZ.

Then I try to open this shapefile. I reproject it to UTM (UTM Zone 33, Northern Hemisphere), and start reading it. I get the following points of the shape:

549340.837580 5155906.01505 12.1631324421

549352.704610 5155906.62361 5.94776381969

549348.444651 5155914.53497 0.0

549340.837580 5155906.01505 **0.0**

The Z coordinate of the last point is incorrect - it is 0, instead of “12.1631324421”.

I tried testing this on polygons with more than 4 points, and noticed that this problem always appears. It’s either the Z coordinate of the first point that is not correct (equals 0) or the last point in the shape.

Is this a bug?

I tested on MapWinGIS “MapWinGIS-only-v5.1.1-x64-VS2015” and “MapWinGIS-only-v4.9.5.0-x64” versions and got the same problem.

The code is ironpython, so I am not sure how much of a help would it be.

I would be grateful for any kind of help or comment.