NEAR 3D compared to NEAR results

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12-19-2013 08:15 AM
by Anonymous User
Not applicable
Original User: mpugh

I am not getting the results i expect in near3d. I have 3d point data representing trees(1600 3d points) and 3d line for powerline(2 lines),
These are created from LiDAR data.
When i use NEAR    (2d) I get correct results( 2d distances) .The same data using Near 3d is not correct
map1 = results near correct near fid in point data red  near line fid=1  ,  green near fid=2

map2  The trees that are now green and red in map 1 are incorrect and calculating distances and z values to line fid=2.

Also the red and green trees that are same in both maps give correct results for NEAR_DIST AND NEAR_DIST3 AND Z VZLUES.

No trees are >50m from any line, but using near 3d have distances up to 280m (in both NEAR_DIST and NEAR_DIST3.
I leave the search radius empty in the near3d tool.

Could this be a bug in NEAR 3D or am i using the tool incorrectly.
Malcolm Pugh
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2 Replies
by Anonymous User
Not applicable
Original User: ggeerraallddiinnee

Hi Malcolm,

Yes there is a bug related to Near 3D:  NIM092999 - The Near 3D tool outputs inconsistent results when calculating near distances.
It was found in 10.1 SP1.
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BenLeslie1
Occasional Contributor III

I notice this bug is still unresolved 3.5 years on - NIM092999: The Near 3D tool outputs inconsistent results when c.. 

This seems quite a long time - do I need to recalibrate my expectations?

Is there an alternative method for calculating nearest distance/angle? - I really only need it for 2D features but I have Intermediate licence with Spatial Analyst so Near 3D is what's available.

I actually get mostly good results but there seems to be some errors and I'm not sure if the fault is the tool or my understanding.

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