Graphics Programs Reference
In-Depth Information
ChAPtER 4
Modeling the Existing
terrain using Surfaces
In Chapter 3,
“Establishing Existing Conditions Using Survey Data,” you
learned how to establish the existing conditions of a project by playing a very
elaborate game of connect-the-dots. So far, you've been solving the connect-
the-dots puzzle in only two dimensions—creating the treelines, fence lines,
buildings, trees, and so on. Now, you'll use the same data to establish the
third dimension of your existing conditions model, and you'll do that using
AutoCAD
®
Civil 3D
®
surfaces
.
Many would say the goal in this process is to generate existing contours for
the project. Twenty years ago, that would have been the case; but in this era
of 3D modeling, the result of your efforts will serve a much greater purpose.
Although it's true that you'll be able to create contours from your surface
model, you'll also create an accurate 3D representation of the ground that can
be used in many ways throughout the project.
In this chapter, you'll learn to
▶
Understand the purpose and function of surfaces
▶
Create a surface from survey data
▶
Use breaklines to improve surface accuracy
▶
edit surfaces
▶
display and analyze surfaces
▶
Annotate surfaces
