ADF Gap

[nkg2]

I have obtained some data from USGS NED files to get my ADF files to create a raster and subsequent contour generation.  Of course MAP3D can't read the ADF file to know what coordinates it is (LL83 btw) and the elevations are typically in meters (which I think, but have not verified, that I translates correctly) but the problem I am having is that I am dealing with such a large area (i.e. a county for example) that is composed of say three to four of the files needed to encompass the area.   However, there is a gap between each of the tiles.   Is there a way to force them to close correctly?

[phil_borycens]

Can you Data Connect to these ADFs in a blank drawing (with no coordinate system assigned)?

Because if the issue only occurs when you are attempting to transform the ADF to a different coordinate system, then that might be part of a known issue with the 2013 and earlier releases. If that's the case, it should be fixed on 2014 (which is available for download now via subscription center or as a trial from autodesk.com).

As far as gaps, how much distance are you talking? (use the MAPDIST command to measure the gap)

How does the gap compare when viewing these ADFs in another (non-Autodesk) program?

[nkg2]

Hi Phil -

The gaps do close when using a vanilla dwg in Map 2013 and assigning no coordinates to them.  I am in the process of cleaning up my computer to install 2014 and apologize for not trying that first.  I did see other posts regarding this but thought maybe I was different.  

One more quick question if you have a second, when I put this together in 2014 and I data connect to the raster images (ADF) it says the coordinate system is unknown and the vertical units unknown.  I know that the NED files package was done in LL83 and the vertical units are in meters.  If I override the adf file and say that it is LL83 and vertical is meters but set my dwg at say MO83-CF, State Plane Coordinate System NAD83 and feet, will 2014 make those corrections?  I have seen other posts to suggest that it does not work at least in the vertical sense.   Thanks in advance and thank you for reviewing.  

[nkg2]

Phil -  So I went to 2014...same situation.   I took a USGS NED file group that contained an ADF file.   Overrided the coordinate system to LL83 and set my drawing to MO83-CF.   Overrided the adf to say my vertical units are in meter so that when the raster is brought in the hope is that it will convert it to feet.   As you can see I am getting gaps.  

The second one is vanilla drawing, no scale and nothing done with the scale.  Everything seems to line up.

Last, I overrode the vertical scale to meters and the coordinate system to LL83 on the raster data connect but left the dwg as vanilla.  Same as the vanilla with just a slight gap.   So it would appear that the translation does not work in 2014.  

[phil_borycens]

I worked on a similar case in the springtime (regarding JPG files from Vermont) and we noticed large discrepancies in the E/W direction (and smaller gaps in the N/S direction). There didn't seem to be any way around it so I logged a change request, which has been confirmed by QA as ID1496165.

In the meantime, the only suggestions that I can really provide are:

• Up your LUPREC variable to its highest value (8)
• Toggle hardware acceleration (in 3DCONFIG > Manual Tune), or try using a different graphics driver
• Try a different file format (maybe GeoTIF or one of the other options that the USGS provides)

I hope this helps at least a little.