Entity Snaps

Commands: 2DINTERSECTION, 3DINTERSECTION, NEAREST, CENTER, ENDPOINT, EXTENSION, FROM, GCENTER, INSERTION, INTERSECTION, MIDPOINT, MTP, NONE, PARALLEL, PERPENDICULAR, POINT, QUADRANT, TANGENT

 

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

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.

If the APBOX system variable is on, the entity Snap Aperture Box is added to the crosshairs when one or more entity snaps are active.

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.

The DRAGSNAP system variable controls the snap behavior while 'dragging', providing an increased WYSIWIG experience. DRAGSNAP controls whether rubberband dynamics are displayed at the current cursor location or at the current entity snap location. DRAGSNAP applies to all modify commands that display dynamics, such as COPY, PASTECLIP, PASTEBLOCK, MOVE, ROTATE, MIRROR, SCALE and STRETCH.

The OSOPTIONS system variable suppresses entity snaps on certain entity types. The value is stored as a bitcode using the sum of the values of the selected options.

NOTE

Press the TAB key, without moving the mouse, to cycle through all possible entity snaps.

If the DYNMODE variable has a positive value (Dynamic Dimensions switched ON) entity snap cycling is not possible. Click the DYNMODE field in the Status Bar to toggle the display of dynamic dimensions.

To define the Entity Snap settings

  1. Open the Settings dialog.

  2. In the Settings dialog, expand the Program Options settings class.

  3. Under Program Options expand the Display settings group, then scroll down to the Entity Snap settings.

 

User Preference

Title

Description

SnapMarkerSize

Snap marker size

Sets the size of the snap marker. (default size is 6)

SnapMarkerThickness

Snap marker thickness

Sets the thickness of the snap marker. (default thickness is 2)

SnapMarkerColor

Snap marker color

Sets the color of the snap marker. (default color = 20)

3dSnapMarkerColor

3d snap marker color

Sets the color of the 3d snap marker (default color = 5 (Blue)).

The 3d snap marker (1) displays the identified 3d point, the snap marker (2) displays at the current Elevation height.

The 3d snap marker displays only if OSNAPZ = 1 ( Ignore entity snap elevation).

 

 

 

 

DisplaySnapMarkerInAllViews

Snap marker in all views

If multiple viewports are open, enables the display of the snap marker in all viewports.

DisplayTooltips

Snap tooltips

Enables the display of the Entity Snap tooltips.

 

  1. Under Drawing expand the Drafting settings group then go to Coordinate Input > Entity Snaps.



 

System Variable

Title

Description

OSMODE

Entity snap mode

Sets the entity snap modes and toggles entity snap on/off.

3DOSMODE

3D entity snap mode

Sets the entity snap modes for 3D entity features such as the midpoint of an edge or the center of a face.

OSNAPCOORD

Entity snap coordinates

Determines whether entity snaps override keyboard coordinate entry.

OSNAPZ

Ignore entity snap elevation

Replaces the Z-coordinate of the snapping point with the current value of the ELEVATION system variable.

OSOPTIONS

Entity snap options

Suppresses entity snaps on hatches and/or dimension extension lines or negative z-values in dynamic UCS mode.

APBOX

Entity snap aperture box

Toggles the display of the aperture box (2).

APERTURE

Entity snap aperture

Sets the size of the Autosnap aperture box. (default size is 10).

DGNOSNAP

DGN entity snap

Enables entity snapping to entities in DGN underlay files.

DWFOSNAP

DWF entity snap

Enables entity snapping to entities in DWF underlay files.

PDFOSNAP

PDF entity snap

Enables snapping to the geometry in PDF underlay files.

To set the Entity Snaps

Do one of the following:

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.

Alternatively you can type a single letter shortcut as indicated in the table below.

Entity Snap Modes

 

Name

Icon

Marker

Context
menu
shortcut*

Transparent

shortcut**

Description

TK

 

tk

Use temporary tracking points. Prompts you to identify temporary points; press Enter to accept the last temporary point.

MTP

 

2

mtp

Snaps to a point in the middle between two points. Prompts you to identify two points.

 

 

 

 

 

 

ENDPOINT

E

end

Snaps to the nearest endpoint of an entity or polyline segment.

MIDPOINT

M

mid

Snaps to the midpoint of an entity or polyline segment.

NEAREST

N

nea

Snaps to the nearest point on an entity.

CENTER

C

cen

Snaps to the center point of an arc, circle, polygon, ellipse or elliptical arc.

Snaps to the center of gravity of a closed polyline.

GEOMETRIC CENTER

G

gce

Snaps to the centroid of any closed polylines and splines, planar 3d polylines, regions and planar faces of 3D solids.

PERPENDICULAR

P

per

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.

PARALLEL

L

par

Displays a tracking line parallel to the selected entity.

TANGENT

T

tan

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

Q

qua

Snaps to the closest quadrant of an arc, circle, ellipse, or elliptical arc.

INSERTION

I

ins

Snaps to the insertion point of an attribute, block or text entity.

POINT

O

poi

nod

Snaps to a point entity.

INTERSECTION

R

int

Snaps to the intersection of any combination of entities.

APPARENT INTERSECTION

A

app

Snaps to the apparent  intersection in the current view of two entities that do not intersect in three-dimensional space.

EXTENSION

X

ext

Snaps to the extension of an entity or to the intersection of the extension of two entities.

NONE

 

Y

non

Turns off all entity snap modes.

* Type this letter to quickly select the entity snap mode in the right click context menu.

** Type the transparent shortcut in the command bar when a command prompts for a point. Other running entity snaps are temporarily disabled.

 

System Variable

Icon

Description

OSNAPZ

Ignore entity snap elevation: replaces the Z coordinate of the snapped point with the current value of the ELEVATION system variable.

OSOPTIONS

Entity snap to hatches: allows to snap to hatches.

OSOPTIONS

Entity snap to negative-z: allows entity snaps with a negative z-value when a Dynamic UCS is active,

 

 

NOTE

You can toggle the Entity Snaps on/off:

  • by clicking the ESNAP field in the Status Bar.

  • by hitting the F3 function key.

 

Working with multiple Entity Snap modes

  1. Move the cursor to the entity you want to snap.
    One of the active Entity Snap modes markers display.
  2. Do not move the mouse; press the TAB key.
    The entity the snap point is on highlights.
  3. Do one of the following:
  4. Click to accept the snap point.
  5. Press the TAB key.
    The next possible Entity Snap mode marker displays.
    The entity the snap point is on highlights.
  1. (option) Repeat step 3 until the right snap point is found.

 

NOTES

  • Do not move the mouse while pressing the TAB key.

  • Entity snap cycling is not possible when Dynamic Dimensions are active. Click the DYNMODE field in the Status Bar to toggle Dynamic Dimensions on/off.

To snap to the extension of two entities

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

  1. Click to accept the snap point.

 

NOTE

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

 

Using temporary tracking points

When using temporary tracking points, Polar Tracking must be on and it is recommended to have dynamic dimensions active as well.

  1. Whenever a command prompts for a point, do one of the following:
  2. Click the Temporay tracking points tool button () on the Entity Snaps toolbar.
  3. Hold down the Shift key, then right click and choose Temporay tracking points in the context menu.
  4. Type TK in the command bar, then press Enter.

The command is suspended temporarily.

You are prompted: Specify first temporary tracking point:

  1. Enter a point, e.g. use an entity snap to specify a point.
    You are prompted: Specify next temporary tracking point (press ENTER to end)
  2. Do one of the following:
  3. Enter a point.
  4. Press Enter to accept the last temporary tracking.

The command resumes.

Using 'Middle of 2 points' snap

  1. When prompted to specify a point, do one of the following:
  2. Click the Snap to the middle of 2 points button () on the Entity Snaps toolbar.
  3. Type mtp or m2p in the command bar, then press Enter.
  4. Press and hold the Shift key, then right click and choose Snap to middle of 2 points in the context menu.

You are prompted: First point of mid:

  1. Specify the first point
    You are prompted: Second point of mid:
  1. Specify the second point.
    The point in the middle of the two points is snapped.

Using the Parallel entity snap

  1. Make sure Entity Snap Tracking is active.
  2. Launch an entity create command to create a linear entity (e.g. Line).
  3. Specify the first point of the entity.
    The line displays dynamically.
  4. Do one of the following:
  1. Hover the cursor over the entity you want to draw parallel to.
    The Parallel Entity Snap marker () displays on the selected entity.
    Wait until a small cross (+) indicates the entity is recognized.
  2. Move the cursor in order to place the dynamics of the line more or less parallel to the selected entity.
    A tracking line displays from the start point of the line.
  3. Do one of the following to specify the second point while the tracking line displays:
  4. Click a point.
  5. Enter the desired length and press Enter.
  6. Use a second entity snap tracking point, then move the cursor to the intersection of the parallel tracking line and the second entity snap tracking line.

 


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