Why does "Interpolate line" create result in integers?

[ShaunDillon]

All of the following is made in ArcMap (editor).
Im trying to use the Profile Graph tool and use the Interpolate line to make a 3d line from our DEM, but the graph is only shown with integer meters and thus very 'stepped.' From the table in Advanced settings on the graph I can see that it is the base values (from Interpolate line) that is in intergers for the z-value, whilst the x value is correct.
I have searched the forums and have tried starting a new mxd and loading DEM first and the dataframe does have projected coordinate system (ETRS_1989_UTM_Zone_32N).
Can anyone help?

[JeffreySwain]

What is your DEM bit depth?  If it is not 32 bit float then that is the issue.  The Interpolate Shape tool will only reflect the values of the DEM with regards to the z values.  If you have an integer raster, then the values will be integer.

[PatrickGrover]

Hi

Just ran into the same problem. My DEM is 32-bit floating point. Tried other DEMs and also had the same issue. When I use the identify tool i get the correct floating-point value of the z elevation.

I corrected the problem by modifying the projection. I was using a custom projection that came with the DEM: North_American_1983_CSRS_UTM_Zone_17N  and changed it over to: NAD_1983_CSRS_UTM_Zone_17N. I have no clue why the projection would impact the units of the extraction.

Hope this helps.

Patrick