Elevation Data Missing In Contours

[AndrewAdams]

Hi Everybody,

I have been pulling my hair out for 3 days on this issue and I desperately need some help!

I am designing a house in Revit and want to use the contour data from real world locations to add context to the house. However, this is not working in ArcGIS...

I have downloaded a TIFF file from the USGS which I have then imported through "Add Data" in ArcGIS. I then re projected the data to UTM (I noticed earlier that when exporting to CAD without this there was no scale data), and I thought this would fix the elevation issue, but it didn't.

I have successfully created the contours, but when I run the Add CAD Data tool, the dataset for everything reads Null. Exporting to CAD the scale is perfect but there is no 3d elevation, it is all just lines on a 2d surface.

I have been reading everywhere and they all say use the georeferencing "Calculate Fields" tool, but I have no clue at all how to use it! I have no idea what calculations or anything I would have to enter to get the z data into elevation. It also seems that ArcGIS is not recognising any elevation info in the TIFF. I have no coding experience and no idea how to enter what is required in the Calculate Field area.

I have run the TIFF in GlobalMapper and generated contours and it works absolutely perfectly, no missing data in AutoCAD or Revit at all.

Please PLEASE can somebody help and put me out my misery!

Thank you!

[DaveEon]

Maybe you need to add elevation information to your contours. Try the interpolate shape tool, using some kind of elevation model, and then your contours will project in a scene view using their 3D z attributes.

ArcGIS Pro's 'ground' concept is exceedingly confusing and poorly implemented. You need to look at elevation surfaces in your Scene settings.

[DonKuehne]

Andrew,

We probably need a little more information to help.  How did you create contours?  If the contours are created as 3D Lines then the EXPORT TO CAD "geoprocessing" tool will generated AutoCAD lines with appropriate z coordinates in the vertices.   The ADD CAD FIELDS tool (assuming that is what you meant).  Really doesn't do anything except add empty fields.  I wouldn't bother with it in your case it will just complicates the workflow.    If you used a method to generate contours in ArcGIS you might already see a field in the attribute table of your data set called CONTOUR.  If what you have is 2D line feature class where there are no Z values on the coordinates of the verticies then the EXPORT TO CAD tool can assign elevation values to the output CAD vectors if the feature has a field called "ELEVATION" and it will then use whatever value you "calculate" into that field.  Those who suggest "calculating a field" are talking about using the geoprocessing tool CALCULATE FIELD  to populate a field called ELEVATION with the values from any field that contains the elevation values you want to be assigned to each feature.  I am suggesting that that field in your case might be called CONTOUR.   Some tools in ArcGIS that create contours generate a field called CONTOURS and populate that value with the elevation value.

It is an oversight that EXPORT TO CAD does not directly read this CONTOUR value.  So, you might consider creating a new  field called ELEVATION  which EXPORT TO CAD will use to overwrite the Z value of vertices for that feature or add that value to the z coordinates for 2D feature classes.  It is unfortunate but you may have created a field already called ELEVATION when you invoked the ADD CAD FIELDS tools and left the value all zeros.  You in effect told EXPORT TO CAD to draw all your 3D contours at an elevation of Zero.   If you have a 2D feature class of contours then you told EXPORT TO CAD to essentially do the same thing... draw all the contours at elevation zero.    You either need to remove the field called ELEVATION and export the 3D contours and they will just draw as 3D contours in the AutoCAD file, or calculate the desired elevations to a field in the feature class called ELEVATION and execute the geoprocessing tool EXPORT TO CAD and it will draw the AutoCAD entities at the elevation value it finds in that field for each feature.

EXPORT TO CAD will draw 3D Feature Classes with their proper 3D coordinates by default, however if you have a field in the feature class called ELEVATION you can populate that field with values and it will draw the features in CAD at that elevation instead.

PS.   I am reminded that, even easier, you could just set the field alias of an existing field that is carrying the elevation values on 2D line features to "ELEVATION" and the EXPORT TO CAD tool will pick up those field values and apply them to each CAD feature when it is output.  In your case this could be the field called CONTOURS? If you don't have a field that contains the elevation values then you could need to find some other way to make 3D features or populate a field with the appropriate values.