Creating Solids and Surfaces from 2D - Autodesk AutoCAD 2013 Practical 3D Drafting and Design - page 89

Chapter 4. Creating Solids and

Surfaces from 2D

Finally, we've come to the main commands for creating 3D models. The commands
explained in this chapter allow you to create solids or surfaces from linear or planar
objects.

In this chapter we will cover:

• How to create solids and surfaces by extrusion
• How to quickly create solids from closed areas
• How to create solids and surfaces by revolution
• How to create solids and surfaces with different sections
• How to create solids and surfaces along a path
• Important variables related to solids and surfaces

Creating solids or surfaces

We can create solids from 2D closed objects, such as circles, ellipses, closed poly-
lines (including rectangles and polygons), and closed splines. Additionally, we can
create solids from regions, 3D faces, 2D solids (created with the SOLID command),
planar faces of 3D solids, planar surfaces, and traces (an obsolete entity created with
the TRACE command).

We can create surfaces (3D objects without thickness) from open linear objects, such
as arcs, lines, elliptical arcs, open polylines, and open splines. We can also create
surfaces from edges of 3D solids and surfaces.

All the commands explained in this chapter, except PRESSPULL , have the MOde op-
tion. This option allows you to choose between Surface and Solid and is useful when
we want to create surfaces from closed objects. Also, the Expression option, allows
the introduction of a formula or mathematical expression whenever a value is reques-
ted, and is transversal to many AutoCAD commands.