Target snapping lets you align elements with targets while manipulating or drawing them. Targets are the elements to which you can snap, such as points, centers, or grid intersections. You can use the target snap feature in conjunction with several different tools, such as Move Point and Add Point. You can define the target types, subtypes, and filters, as well as set other snap options.
To snap elements to targets, you simply need to activate snapping. If necessary, you can define the targets to which to snap as described in Snapping to Targets. Targets are defined by their type and subtype. In addition, you can use a filter to further refine the valid targets.
You can also set various snapping options as described in Setting Options for Snapping to Targets, as well as set the grid size as described in Controlling Grid Size for Snapping.
To activate and deactivate snapping
With snapping on, you can use any tool that supports snapping — for example, translate an object or draw a curve. A box appears around the mouse pointer, indicating the current Region Size.
As you drag the mouse, the element you are manipulating snaps to targets within the snap region. The target subtype is displayed below the snap region — this is useful to distinguish targets when multiple types and subtypes are active.
When translating, the point that snaps to the target is the pivot. This is normally an object's center (if COG is off) or the center of geometry (if COG is on for any type of element, or if Transform 
Collapse Points When Snapping is on in the case of points only). However, you can set the pivot manually as described in Setting the Pivot.
Snapping and Manipulation Modes
When snapping is on, the various manipulation modes (Global, Local, View, Par, Object, Ref, and Plane) change behavior.
When snapping to targets other than the grid:
If you restrict the manipulation to specific axes, those axes are projected onto the camera plane.
When a target is found in a perspective view, the element snaps to it in 3D space.
When a target is found in an orthographic view, the behavior depends on an option — see Use 2D Snapping in Orthographic Views.
When snapping to the grid, the different manipulation modes use different grids. See Controlling Grid Size for Snapping.
Tools That Use Target Snapping
You can snap objects and components to targets while using many tools:
The Translate tool, activated by pressing V or by clicking the t icon on the Transform panel.
The Tweak Component tool, activated by pressing M or by choosing Modify Component Tweak Component Tool from the Model toolbar.
The Tweak Curve tool, activated by pressing M while a curve is selected or by choosing Modify Curve Tweak Curve from the Model toolbar.
The Move Point tool, activated by choosing Modify Component Move Point Tool from the Model toolbar.
The View Plane Proportional Transform tool, activated by choosing Modify Component View Plane Proportional Transform Tool from the Model toolbar.
The View Plane Pivot Transform tool, activated by choosing Modify Component View Plane Pivot Transform Tool from the Model toolbar.
Any of the Draw commands, available from the Create Curve menu on the Model and Animate toolbars.
The Add Point tool, activated by pressing Ctrl+Insert or by choosing Modify Curve Add Point Tool from the Model toolbar.
The Add/Edit Polygon tool, activated by pressing N or by choosing Modify Poly. Mesh Add/Edit Polygon Tool from the Model toolbar.
The Split Polygon tool, activated by choosing Modify Poly. Mesh Split Polygon Tool from the Model toolbar.
The Duplicate tool, activated by pressing D or choosing Edit Duplicate/Instantiate Duplicate Tool.
The 2D Chain and 3D Chain tools, activated by choosing Create Skeleton 2D Chain or 3D Chain from the Model or Animate toolbars.
Note that for 2D chains, snapping works only for the first two bones. After that, subsequent bones are forced to remain in the plane defined by the first two bones.
The Move Joint/Branch tool, activated by choosing Create Skeleton Move Joint/Branch from the Model or Animate toolbars.
