OK, understood. You have provided vital information to get the wheels rolling.
Before we begin, it is vital to verify whether your drawing is accurately georeferenced. If you learn one thing today, let it be this:
Just because you 'assign' a coordinate system to modelspace doesn't necessarily mean your dwg file is georeferenced against world coordinates.
To begin, you must determine whether the coordinate system you have assigned is appropriate to your map area AND determine whether it is georeferenced against the equator & north pole. The reason you want it georef'd against the equator & north pole is because others, such as maintenance personnel, might use your hand drawn objects in their AutoCad files as external references or as cut-and-paste objects. They might even use your drawn objects in GIS-essy types of programs such as ArcGIS, Arc Pro, QGIS, Global Mapper, etc, etc. If both your files and their files are georef'd against world coordinates then everything lines up. If your coordinate system is assigned but NOT accurately georef'd against the equator/north pole, then it's on you, not them, when your objects don't line up correctly with theirs.
To determine whether your CS is accurate, turn on Bing Hybrid. Go to Geolocation Tab=>Online Map Panel=>change Map Off to Bing Hybrid. (If Bing Hybrid doesn't appear in modelspace, you may have issues, serious issues.) Pan and zoom-in to your area (or 'an area') you know in your city then draw a circle the approximate size of four city blocks. Select the circle then take a screen shot of modelspace (make sure the entire circle can be seen) and upload the captured image to the forum. Name the coordinate system you have assigned so the forum can duplicate your map's drawing environment. It is also important to include the properties palette in your screenshot so the coordinates of the selected circle can be easily read. This uploaded image, along with your assigned Coordsys, will help to determine the geospatial accuracy of your drawing.
If it is georefenced accurately then you are making excellent progress with your drawing using Map3D. On the other hand, if your drawing is not georeferced correctly, then an easy step-by-step workflow will be given to make the correction.
Note:
Learning Map3D is not a one-and-done deal, it's a process (sometimes lengthy, sometimes not) and you are getting that process in a few (or more than a few) forum posts at no cost to you. The purpose of this forum, and all forums for that matter, is to share the knowlege. Your willingness to share your uploaded images will not only ascertain the accuracy of your assigned coordsys, but it will also provide some info on where to find and download the free data you need. Without knowing your desired area of interest, it will be too difficult, maybe even impossible, to offer suggestions where you can acquire your data. Make no mistake, if the forum doesn't know your area it might derail this post and your project might come to a screeching halt.
Chicagolooper
