Over the past few months I've been seeing questions from users who are trying to are trying to use Bing map data, or who are trying to work with data from GIS systems. Many of the problems that users are dealing with are related to setting up the coordinate system for your drawing. So - I'm posting my workflow to show people what works for me.
First, start a new drawing from a Civil3d template. I'm working in metric for this example, but the process for Imperial units is the same. If you started from an OOTB template then this dialog won't have a coordinate system, so pick the one you intend to use.
Switch to the Transformation tab and look at the values. This is a pitfall that catches most C3d users, so a little background info. Civil3d is built on top of the Autodesk Map platform. The Bing Map functions are part of Map, which is why you have to change workspaces to use them. Map is also the tool for import/export of GIS data, shapefiles and coordinate transformations etc. The underlying problem is that the Map programmers assume that data being imported or exported will be in spherical coordinates, (Latitude and Longitude) while the Civil3d programmers assume that data will be in grid coordinates.
When you set a coordinate system Map will plug in the values as shown below. The local values are at the center of the useful range for this coordinate system. The second set of values are the same location in Lat & Long, but since C3d assumes these fields are Grid coordinates your data gets shifted. Note - the transformation tab is turned off, which means that C3d won't use it but Map doesn't care. Bing Maps and other data imported using Map will be affected by these values, so they have to be set correctly.
Secondary issue - you might find that the values are not set here by Map. This likely means that you've started from a template that already had a coordinate system assigned by C3d, but the Map tools are not set. Use the MAPCSASSIGN command to set any random coordinate system, then use it again to set the system you want to use. You should find that the Transformation tab has values after that.
If your project will be in Grid coordinates then simply copy the local values to the Grid values. If your data will be scaled or translated to a local coordinate system then the settings will be a little more complex. When I have a dataset to use for an example I'll post that later.
Remember the red pushpin icon that appeared a few versions back. Everybody wanted to know how to turn that off, but if you're trying to confirm that your coordinate system is setup correctly then set GEOMARKERVISIBILITY = 1 and zoom to the reference point. Turn on the Bing map. You should find that the marker is in the center of the map extents; zoom way out to check this, and the coordinate values are as shown above.
Autodesk University 2016 is coming up, so as a test I used Google Earth to trace the outline of the Venetian Hotel and the Sands Convention Center. I then used GPS Visualizer to convert the kmz file into text, and imported that into C3d. It matches the Bing Map location as expected, which confirms that this drawing is working properly.
Shameless plug - The Expert Elites who you see on these forums answering your questions are hosting a class at Autodesk University 2016. Please feel free to register for this session and join us.
DP15338 - Getting To Know You – A Guide to Connecting With Peers in the Autodesk Community
There will also be Expert Elites hanging around the Exhibit Hall, look for our booth there too.
