Surface from objects

 

One method of creating a terrain model is to select objects in the drawing:

This can be a land survey or a supplied drawing of the situation. The objects do not have to be drawn in 3D although that is preferred. That makes the model more accurate and reliable. If there are no 3D objects available but spot elevation texts, the model is created based on the textual values after which any line object is projected to the elevations.

A Surface can be supplemented later with Civil 3D functionality with better data, if for example a control survey has been performed.