9.5.2

306 • CHAPTER 7
OBJECTS MENU • SPECIAL MODELING TOOLS • 307
Symmetry Object
The Symmetry object works with geometry and splines only, not with lights,
cameras and so on.
The Symmetry object (Objects > Modeling) is especially useful when polygon modeling symmetrical
(or nearly symmetrical) objects such as faces. Model just one half of the object and the other half
is generated automatically. Once you’ve nished modeling one side you might want to make the
Symmetry object editable to convert the generated half into polygons. You can then tweak either side
separately to avoid the model looking unnaturally symmetrical.
Try something simple: create a sphere, convert it to polygons with Functions > Make Editable and
select the Points tool. Select the Rectangle Selection tool and, in the Front view, select the right half
of the Sphere object’s points and delete them. Create a Symmetry object and, in the Object manager,
make the sphere a child of the Symmetry object.
The right half of the sphere is generated and the sphere is complete once more. Note that only the
left-hand side has points. Now edit some of the points on the left-hand side, perhaps with the Magnet
tool. Notice how the generated side is updated automatically.
Attribute manager settings
Object Properties
Mirror Plane
Determines which plane is used as the mirror. ZY is the default since it is used in the front view for
objects with vertical symmetry, such as a face.
Weld Points, Tolerance
If the Weld Points option is enabled, points at the mirror’s edge are welded automatically — two points
become one. This joins the object smoothly, avoiding a seam along the middle. Enter the maximum
weld radius in the Tolerance box. Points that are within this distance to each other will be snapped
together and welded.
Symmetrical
Enable this option if you want to ensure that the welded points (Weld Points enabled) are placed
exactly on the mirror axis. Otherwise, each welded point is placed midway between the points from
which it was formed — this may or may not be on the mirror axis depending on whether the points
are the same distance from the mirror axis.