2009

Mirror copying a mesh
Once you’ve finalized one half of your polygon model (and deleted its
construction history) you’ll want to create the opposite half by copying it
across the axis of symmetry so you have the complete model. You can produce
a mirrored copy of a polygon mesh using Mirror Geometry (Mesh > Mirror
Geometry).
Before copying one half across the axis of symmetry, you should check that
all of the border edges lie along the axis of symmetry. If any edges do not lie
along this axis, the original half will be copied based on the vertices that create
the widest point and a gap between the two halves may result.
To ensure that the border vertices lie along the axis of symmetry
1 Enlarge the front view so you can view the vertices that lie along the axis
of symmetry.
If any vertices on the mesh protrude across the Y axis, you’ll need to snap
these to the Y axis using the Move Tool in combination with the Snap
to grids feature.
NOTE Any vertices that protrude across the Y axis likely occurred as a result
of an earlier extrude operation. Because the extrude feature extrudes
components based on the face normal, a few vertices may have moved across
the axis of symmetry.
2 In the front view, select all of the vertices that should lie along the axis
of symmetry (Y axis) using a bounding box selection.
3 On the Status Line, turn on Snap to Grids.
4 In the Toolbox, double-click the Move Tool to display its tool settings
and ensure that the Retain component spacing setting is turned off.
5 In the front view, click-drag the red arrow on the Move Tool manipulator
to the right a small distance.
The vertices immediately snap to the grid line to the right. They initially
will not be positioned at the location you want, but you’ll notice that all
of the vertices you selected are now aligned to each other.
6 Drag the manipulator towards the left until the vertices snap to the Y
axis.
122 | Chapter 3 Polygonal Modeling