Graphics Reference
In-Depth Information
Using the Transform Tools
In modo, as in all 3D applications, there are controls to move, rotate, and scale objects. These tools are col-
lectively known as
transform tools
. When activated, tool handles appear onscreen. The handles for Move
and Scale are a set of axes. The center of the axes represents the center point, from which the action will ori-
ginate (known as the Action Center). The two tools are differentiated by the widgets at the end of each axis.
For the Move tool, the axes terminate in arrows, and the Scale tool handles end in boxes. The orientation
of the handles (the axis) controls the direction that transformations are applied when using the tool handles.
These handles can be changed based on a number of parameters discussed in the next section. The Rotation
tool consists of three circles (one for each axis). Like the Move and Scale tools, you can change the center
and the axis by adjusting the Action Center.
Aside from editing using the axes, the transform tools also feature additional handles. The Move and
Scale tools can be adjusted by using planar handles (the circles that are set in space at the intersection of the
handle endpoints). Dragging these handles will adjust the selection in two dimensions at once. Additionally,
the Scale tool features a central handle that scales in all axes simultaneously. Rotation is already based on
a plane (as opposed to an axis, like the other transform tools) so there is not a different set of handles for
planar rotation. There is, however, a gray handle for viewport rotation. This handle always rotates the selec-
tion on the plane that is perpendicular to the current perspective.
Understanding Action Centers
Another piece of the modeling puzzle focuses on the point from which transformations (move, rotate, scale)
take place and the orientation of the axes that drive them.
Action Centers
are made up of a center and an
axis. Action centers can be changed through the menu located at the top of the screen, next to the component
modes (Vertex, Edge, Polygon, and Items). By default, the Action Center is set to Automatic, which ini-
tially places the action center in the middle of the selection, with the axes aligned with the world orientation.
Clicking on the transform handles will re-center the center to the click point. In an orthographic view, this
will center at the click point for the two dimensions visible in the view and at the origin in the third axis. In
a perspective view, the tool will center to the position on the Work Plane under the mouse location. The axis
will remain aligned to the world axes regardless of the center. Here is a quick rundown of the other action
center presets:
Selection
In this setting, the tool handles center on your current selection, and their orientation is based
on the average direction the polygons are facing in the selection.
Selection Border
This preset finds the open edge of the selection and is defined by the average position
and orientation of that edge.
Selection Center Auto Axis
This setting behaves much like the Automatic Action Center but will not be
moved by clicking the transform handles. The center is locked to the center of the selection.
Element
This very useful setting aligns the position and orientation of your tool handles to any vertex,
edge, or polygon in your scene. Simply activate a tool and click on the desired element. The elements will
be highlighted when the cursor rolls over, and the tool will align when clicked. This can be recentered at
will.
Screen
In this setting, the handles of a tool are aligned to be perpendicular to the viewport. The position
of the tool will align to your mouse click.
