Entity Snaps

Entity snaps enable you to quickly select exact geometric points on existing entities without having to know the exact coordinates of those points. With entity snaps, you can select the end point of a line or arc, the center point of a circle, the intersection of any two entities, or any other geometrically significant position. You can also use entity snaps to draw entities that are tangent or perpendicular to an existing entity. You can use entity snaps any time you need to specify a point.

You can work with entity snaps in one of two ways

Enable a running entity snap that remains in effect until you turn it off by choosing an entity snap when no other command is active.
Enable a one-time entity snap for a single selection by choosing an entity snap when another command is active. You can also use a one-time entity snap to override a running entity snap.

When using entity snaps, the program recognizes only visible entities or visible portions of entities. You cannot snap to entities on layers that have been turned off or to the blank portions of dashed lines.

When you specify one or more entity snaps, the entity Snap Aperture Box is added to the crosshairs. In addition, an icon appears adjacent to the crosshair indicating the active entity snap (Snap cursor decoration). When you move the cross hairs, the program snaps to the snap point closest to the center of the Snap Aperture Box. The Snap Marker indicates the current snap point. Press the TAB key to cycle through all possible entity snaps.

To define the Entity Snap settings

Do one of the following:
Click the Settings tool button () on the Settings toolbar.
Choose Settings in the Settings menu.
Type settings in the command bar, then press Enter.

The Settings dialog opens.

In the Settings dialog, expand the Program Options settings class.
Under Program Options expand the Display settings group, then scroll down to the Entity Snap settings.

Define the Entity Snap settings.

Setting	Description
Snap flyover	Enables Entity Snap.
Snap marker (1)	Enables the display of the snap marker.
Snap marker size	Sets the size of the snap marker. (default size is 6)
Snap marker thickness	Sets the thickness of the snap marker. (default thickness is 2)
Snap marker color	Sets the color of the snap marker.
Snap marker in all views	If multiple viewports are open, enables the display of the snap marker in all viewports.
Snap tooltips (2)	Enables the display of the Entity Snap tooltips.
Snap aperture box (3)	Sets the size of the Entity Snap aperture box. (default size is 10)
Snap cursor decoration (4)	Enables the display of the current Entity Snap icon adjacent to the cross hairs.

NOTE	You can toggle the Entity Snaps on/off by double clicking the ESNAP field in the Status Bar.

To set the Entity Snaps

Do one of the following:

Click the buttons on the Entity Snaps toolbar.
The buttons of the currently active Entity Snap modes are pressed.
Press and hold the Shift key, then right click and select the entity snap mode in the context menu.
The icons of the currently active Entity Snap modes are outlined.

When no command is active, the above procedures toggle the Entity Snap modes on/off.

When a command is active, the above procedures set a 'one shot' override of the current Entity Snap modes.

Entity Snap Modes

Name	Icon	Marker	Description
Nearest			Snaps to the nearest point on an entity.
Endpoint			Snaps to the nearest endpoint of an entity or polyline segment.
Midpoint			Snaps to the midpoint of an entity or polyline segment.
Center			Snaps to the center point of an arc, circle, polygon, ellipse or elliptical arc. Snaps to the center of gravity of a closed polyline.
Perpendicular			Snaps to the perpendicular point of another entity. You can snap to an arc, circle, ellipse, line, polyline, infinite line, ray, spline or edge of a plane to form a perpendicular alignment with that entity or with an extension of that entity.
Tangent			Snaps to the point on an arc, ellipse, spline or circle that, when connected to the previous point, forms a line tangent to that entity.
Quadrant			Snaps to the closest quadrant of an arc, circle, ellipse, or elliptical arc.
Insertion			Snaps to the insertion point of an attribute, block or text entity.
Point			Snaps to a point entity.
Intersection			Snaps to the intersection of any combination of entities.
Apparent Intersection			Snaps to the apparent intersection in the current view of two entities that do not intersect in three-dimensional space.
Extension			Snaps to the extension of an entity or to the intersection of the extension of two entities.
Clear			Turn off all entity snap modes.

Working with multiple Entity Snap modes

Move the cursor to the entity you want to snap.
One of the active Entity Snap modes markers display.
Press the TAB key.
The entity the snap point is on highlights.
Do one of the following:
Click to accept the snap point.
Press the TAB key.
The next possible Entity Snap mode marker displays.
The entity the snap point is on highlights.

(option) Repeat step 3 until the right snap point is found.

NOTE	If you keep pressing the TAB key you can cycle through all possible snap points.

To snap to the extension of two entities

If not already on, turn on the Extension Entity Snap mode ().
Launch a drawing tool, e.g. Draw Line.
Move the cursor over the endpoint of the first entity (1).
A small cross () indicates the entity is marked for extension.
Move the cursor over the endpoint of the second entity (2).
A small cross () indicates the entity is marked for extension.
Move the cursor near the intersection of the extensions of the two entities.
An X indicates the intersection (3).

Click to accept the snap point.

NOTE	You can snap to the extension of lines, polylines, arcs and elliptical arcs