This question came up last week and i thought it worth capturing here.
In TBC you can uae the Capture Image command to capture a high res image of what is visible on screen either using a plot box to limit the capture or just the extents of the graphics display. The image captured can be a jpg, png or Tif image. The image is caoturwd with a world sidecar file (jgw, pgw, tfw) and a KML file (for placing the image in Google Earth. The image that is captured is placed in the Snapshots sub folder of the project folder for the current TBC project. The TBC project can have a coordinate system or site cal which allows the world file generayed to place the image in the correct WGS84 geo location. Without a coordinate system or site cal the image captured will be a local coordinate only.
To load the image into AutoCAD Civil 3D do the following
Open your AutoCAD drawing file
Run the MAPIINSERT command (yes two iās) feom the command line. Pick the image format that you have created and select the file (jpg, png, tif) and it will load into the graphics of the open dwg file. It should underlay the cad linework for the project automatically
I recommend capturing the image at 300 DPI and if the area pf the project is too large at that resolution create a couple of plotboxes to subdivide the site and capture two images etc to reduce the area of the images to keep the image files at the desired resolution.
Alan