The grid shown in the viewer is the construction plane. Many modeling operations, such as creating a new objects using the tools in the Create shelf tab, are relative to the construction plane.
You can change the display of the grid on the construction plane, or move/reorient the construction plane to make it easier to model in an area not centered on the origin, or in a space other than the XZ ground plane.
The viewport options menu has three items for editing the construction plane.
|Construction plane parameters|
This window lets you control how grid lines are drawn along the construction plane:
|Construction plane handle|
Turn on this option to show a handle that lets you quickly move and orient the construction plane in the viewer.
|Set construction plane|
This sub-menu contains many commands for snapping the construction plane to common orientations, re-centering the construction plane, and flipping the plane.
To return the construction plane to the default, open the viewport options menu and choose Set construction plane > Rever to defaults.
Use the snapping icons in the toolbox (one the left side of the viewer pane) to turn snapping on and off.
Right-click, or press and hold, an icon to see a menu of options.
|Snap to grid|
Snap to points on the construction plane.
|Snap to primitives|
Snap to curves and edges.
|Snap to points|
Snaps to points.
Snap to different things simultaneously. Open the icon’s menu and choose Multi-snapping options to set priorities for individual types of snapping.
At the Geometry level, you can snap to geometry from other objects, not just the object you are inside.
If you turn this option off, you can snap to reference geometry, but the point stays on the construction plane].
|Orient on snap|
When you snap one object to another, normally the orientation of the object will remain the same and only its location will change. If this option is turned on, the object will rotate so the closest major axis (x, y, z) points in the direction of the thing you are snapping to.
Open the snapping options window containing additional options. For multi-snapping, this window lets you give each type of snapping different priorities so, for example, snapping to points overrides snapping to edges.
You can align objects using handle snapping:
Select the first object with the Transform tool and press to finish the selection.
Press T to switch to the translate manipulator.
To temporarily detach the manipulator from the object, select the handle and press '.
Press on the handle and choose Align Handle > Start Orientation Picking. Click two adjacent edges of a face on the object to move the manipulator to their intersection.
Press ' again to reattach the manipulator to the geometry, so moving the manipulator will move the geometry along with it.
Press on the handle and choose Align Handle > Start Orientation Picking. This time, click two adjacent edges of a face on the other object to move the manipulator to their intersection.
When you snap the first object’s manipulator to the edges on the other object, it moves and orients the first object.