Object Snap Sacramento City College Engineering Design Technology Object Snap 1
Objectives Use OSNAP to create precision drawings Use object snap overrides for single point selections Set running object snap modes for continuous use Use Autotrack and temporary tracking modes to locate points relative to other points in a drawing. Object Snap 2
OSNAP Object Snap 3
OSNAP The OSNAP feature of AutoCAD Means object snap It increases your drawing performance and accuracy. Is one of the most useful tools in AutoCAD. Refers to the ability to snap exactly to a specific point or place on an object. Endpoint of line Midpoint of line Centerpoint of circle Object Snap 4
Object Snap AutoTrack Creates and deletes construction lines automatically. Object Snap 5
AutoSnap OSNAP Uses Visual cues to indicate the object snap point that has been selected by AutoCAD. Endpoint Cue A square when the cursor is placed near the object. Midpoint Cue A triangle when the cursor is placed near the object. Object Snap 6
Object Snap 7
The Object Snap Modes Two methods of activating object snaps 1. Running object snaps 2. Snap Overrides Both display visual cues as markers Object Snap 8
Object Snap Modes Object snap overrides Can be used while inside a command, however, they are not commands. They are a one-time override of the OSNAP choices. Only that OSNAP choice will be active when selecting points They can be entered 3 ways 1. Typing abbreviation at Command: prompt 2. Selecting from OSNAP Toolbar 3. Selecting from right-click menu Object Snap 9
Setting Running Object Snaps Object Snap 10
Setting Running Object Snaps Running object snaps. Are preset object snap modes Selected by user in OSNAP dialog box by checking the check box for that OSNAP. When selected, AutoCAD automatically activates them at all point selection prompts. Object Snap 11
Setting Running Object Snaps Set by 1. Typing OSNAP at Command: prompt 2. Pick Object Snap Settings button from the Object Snap toolbar 3. Tools > Drafting Settings 4. Right-click on the OSNAP or OTRACK button on the status bar and select Settings Object Snap 12
Object Snap 13
Object Snap 14
OSNAP Overrides Object Snap 15
Object Snap Override An object snap override can be obtained from 1. The Object Snap toolbar. 2. The Object Snap Override menu activated by [Shift-Right-Click]. 3. Typed in from the keyboard. Object Snap 16
Object Snap Override OSNAP Overrides Is the entry of an object snap mode at a point specification prompt. Are active for one point specification only, Override any previously set object snap modes for that entry. Object Snap 17
Object Snap 18
OSNAP Toolbar Object Snap 19
Overriding Running Object Snaps Running object snap Is always active if OSNAP is ON. is suspended with an object snap override. To make a single point selection without the effects of any running object snap, enter the None object snap mode Object Snap 20
OSNAP ON/OFF Object Snap 21
OSNAP ON/OFF Object snap On/Off The button at the bottom of the screen F3 Object Snap 22
Object Snap Modes Object Snap 23
Object Snap Modes Endpoint Object Snap finds the nearest endpoint of a line, arc, elliptical arc, spline, ellipse, ray, solid or multiline. This snap setting is often selected as a running object snap. Object Snap 24
Endpoint Object Snap Endpoint Object Snap Override: Type END at the prompt OR Pick the Endpoint button on OSNAP Toolbar OR Select Endpoint from the right-click cursor menu Position cursor near endpoint of the object. Prompt is a small square. Object Snap 25
Endpoint Object Snap Object Snap 26
ENDPOINT Object Snap 27
Object Snap Modes Midpoint Object Snap finds the middle point of any object, having two endpoints, such as a line, arc, elliptical arc, spline, ellipse, ray solid, xline or multiline. Object Snap 28
Midpoint Object Snap Midpoint Object Snap Override: Type MID at the prompt OR Pick the Midpoint button on OSNAP Toolbar OR Select Midpoint from the right- click cursor menu Position cursor near midpoint of the object. Prompt is a small triangle marks the midpoint where the line will snap. Object Snap 29
Midpoint Object Snap Object Snap 30
MIDPOINT Object Snap 31
Object Snap Modes Center Object Snap locates the center point of a radial object, including circles, arcs, ellipses, elliptical arcs, radial solids. Object Snap 32
Center Object Snap Center Object Snap Override: Type CEN OR Pick Center button on OSNAP Toolbar OR Pick Center from the right-click cursor menu Locate cursor near object whose center is to be located. Prompt is a small circle. Object Snap 33
Center Object Snap Object Snap 34
CENTER Object Snap 35
Quadrant Object Snap A quadrant is a quarter section of a circle, doughnut, ellipse, elliptical arc or arc. Object Snap 36
Quadrant Object Snap Quadrant Object Snap Quadrant - picks the closest of the four quadrant points that can be found on circles, arcs, elliptical arcs, ellipses, and radial solids. 0 o 90 o 180 o 270 o Move cursor near one of these locations to snap to them. Object Snap 37
Quadrant Object Snap Quadrant Object Snap Override: Type QUA OR Pick Quadrant Button on OSNAP Toolbar OR Pick Quadrant from the right-click cursor menu Prompt is a diamond that marks the quadrant. Object Snap 38
Quadrant Object Snap Object Snap 39
Quadrant Object Snap Object Snap 40
QUADRANT Object Snap 41
Intersection Object Snap Intersection Object Snap Snaps to the intersection of two or more objects. Override: Type INT OR Pick Intersect Button on OSNAP Toolbar OR Pick Intersection from the right-click cursor menu Prompt is a small x that marks the intersection Only appears when the cursor is close to the intersection point of the two objects Object Snap 42
Intersection Object Snap Object Snap 43
Intersection Object Snap Object Snap 44
INTERSECTION Object Snap 45
Object Snap Modes Extended Intersection - selects an intersection point between two objects which, if they were extended, would intersect at that point. This is useful when two objects do not actually intersect and you need to access the point where these objects would intersect if they were extended. Is only available as a snap override. Object Snap 46
Extended Intersection Object Snap Extended Intersection Object Snap To activate Extended Intersection, select the Intersection object snap override and pick an object (rather than an intersection). If the cursor is near an object but not close to an actual intersection, the SnapTip reads Extended Intersection AutoCAD finds a projected intersection point of the two objects. Very useful when two objects do not intersect. Object Snap 47
Extended Intersection Object Snap Extended Intersection Object Snap If the intersection point is not in the currently visible screen area, the AutoSnap marker is not displayed when you select the second object. You can still confirm the point before picking, however. Keeping the crosshairs motionless over the second object displays the tooltip, which confirms that the objects intersect somewhere beyond the currently visible area. Object Snap 48
Extended Intersection Object Snap Object Snap 49
EXTENDED INTERSECTION Object Snap 50
Apparent Intersection OSNAP Apparent Intersection - selects a visual intersection between two objects that appear to intersect on the screen, but may not intersect in 3d space. 3D application only. Object Snap 51
Apparent Intersection OSNAP Apparent Intersection Object Snap is the point where two objects appear to intersect based on the currently displayed view. Three-dimensional objects that are far apart may appear to intersect on the screen. This is a valuable option when working with 3D drawings. Not so useful for 2D. Object Snap 52
Perpendicular Object Snap Perpendicular Object Snap Allows you to draw one object perpendicular to another object Override: Type PER at the selection prompt Pick Perpendicular button on OSNAP Toolbar Pick Perpendicular from the right-click cursor menu Prompt is a small right angle Object Snap 53
Perpendicular Object Snap Perpendicular Object Snap This mode can be used with arcs, elliptical arcs, ellipses, splines, xlines, multilines, polylines, solids, traces, or circles Object Snap 54
Object Snap 55
Perpendicular Object Snap Object Snap 56
Perpendicular Object Snap A deferred perpendicular means the calculation of the perpendicular point is delayed until another point is picked. The second end point determines the location of the entire line. Object Snap 57
Perpendicular Object Snap Important! Perpendicular is calculated from points picked, NOT as a relationship between objects. Perpendicularity is measured at the point of intersection so it is possible to draw a line that is perpendicular to a circle or an arc. Object Snap 58
Perpendicular Object Snap Object Snap 59
Tangent Object Snap Tangent Object Snap Can use with arc, circle, ellipse, elliptical arc, and spline. is similar to the Perpendicular Object Snap Aligns objects tangentially. Override: Type TAN at the selection prompt Pick Tangent button on OSNAP Toolbar Pick Tangent from the right-click cursor menu Object Snap 60
Tangent Object Snap When creating an object that is tangent to another object, multiple points may be needed to fix the tangency point. The point at which a line is tangent to a circle cannot be found without knowing the location of both ends of the line. Until both endpoints have been specified, the object snap specification is for deferred tangency Object Snap 61
Parallel Object Snap Parallel Object Snap Allows you to find any point along an imaginary line that is parallel to an existing line or polyline. Object Snap 62
Parallel Object Snap Parallel Object Snap Override: Type PAR at the selection prompt Pick Parallel button on OSNAP Toolbar Pick Parallel from the right-click cursor menu Parallel OSNAP is similar to Extension because it requires more than one selection point. Object Snap 63
Parallel Object Snap The acquired point is found by pausing the crosshairs over any point on the line to which the new object is to be parallel. When the object is found and you move the crosshairs in a direction parallel to the existing line, a (//) symbol marks the existing line. A dashed line, parallel to the existing line, extends from the location of the crosshairs. This line is known as the parallel alignment path. Object Snap 64
Parallel Object Snap The last point, which is the actual snap point, can be placed anywhere along the parallel alignment path. When the alignment path is displayed, the Parallel snap marker appears on the line from which the parallel is used. Picking any location along the parallel alignment path creates the second point of the parallel line. Object Snap 65
Parallel Object Snap Object Snap 66
Object Snap 67
Object Snap 68
Object Snap 69
Object Snap 70
Node Object Snap Node Object Snap POINT objects can be snapped to using the Node object snap mode. To FIND the POINT, the POINT must be in visible display mode. Affected by setting of the PDMODE system variable. Object Snap 71
Nearest Object Snap Nearest Object Snap Use to specify a point on an object but which cannot be specified from any of the other snap modes. Use when you want an object to touch an existing object, but the location of the intersection is not critical Object Snap 72
Nearest Object Snap Nearest Object Snap Example: Consider drawing a line object that is to end on another line. Trying to pick the point with the crosshairs is inaccurate because you are relying only on your screen and mouse resolution. The line you draw may fall short or extend past the line. Using Nearest ensures that the point is precisely on the object. Object Snap 73
Multiple OSNAPs Object Snap 74
Using Multiple Object Snaps More than one object snap mode can be made active at once. When more than one is active, AutoCAD picks the closest point. This can cause conflicts! Object Snap 75
Using Multiple Object Snaps OSNAP Conflict Example CEN and QUA conflict with each other. No matter where you pick a circle, the closest quadrant point is always closer than the center of the circle. So When quadrant and circle are both set active, a quadrant point is always picked. Object Snap 76
Using Multiple Object Snaps OSNAP Conflict Example NEA (Nearest) Conflicts with almost every other mode. Nearest mode always locates the point closest to the current cursor location. Object Snap 77
Using Multiple Object Snaps The Tab key can be used to cycle through available snap points. Press the Tab key repeatedly until the desired point is marked. Object Snap 78
Changing the Aperture Size Object Snap 79
Changing the Aperture Size When selecting a point with OSNAP, the cursor must be within a specific range to a point before it is located. The object snap detection system finds everything within a square area centered at the crosshairs location. This square area is called the aperture and is invisible by default. Object Snap 80
Changing the Aperture Size Aperture To display the aperture, pick the AutoSNAP tab and activate the Display aperture box check box. Aperture box size is measured in pixels Object Snap 81
Changing the Aperture Size The aperture size can also be set from the Command prompt Command: APERTURE Object snap target height (1-50 pixels) Command: Object Snap 82
AutoSnap Settings Object Snap 83
AutoSnap Settings AutoSnap options Additional visual cues can be turned off The appearance of AutoSnap and functionality can also be changed Object Snap 84
AutoSnap Settings Marker - toggles the AutoSnap marker Magnet - toggles the AutoSnap magnet When active, the magnet snaps the cursor to the object snap point. SnapTip - toggles the SnapTip display Display aperture box - toggles the display of the aperture box Marker color - changes color of marker Marker size - changes marker size Object Snap 85
Object Snap 86
Object Snap Tracking Object Snap 87
Object Snap Tracking Object SnapTracking allows you to visually locate points in a drawing relative to other points. When this mode is active, placing the crosshairs near an AutoSnap marker acquires the point. After a point is acquired, horizontal and vertical alignment paths are available for locating points. Object Snap 88
Object Snap Tracking To activate Tracking 1. Pick the Tracking button from the Object Snap toolbar 2. Type TK or TRA at the point selection prompt. Pick Tracking from the cursor menu. 3. F11 4. OTRACK button on the status bar. Object Snap 89
Object Snap Tracking Tracking is only available for points selected by the currently active object snap modes. 1. Pick the Tracking button from the Object Snap toolbar 2. Type TK or TRA at the point selection prompt. Pick Tracking from the cursor menu. 3. F11 4. OTRACK button on the status bar. Object Snap 90
Object Snap Tracking Object snap tracking can also be used to position new geometry based on the locations of existing geometry. Object Snap 91
Object Snap Tracking Example: In the next slide, Object snap tracking is used to position a circle directly above the midpoint of a horizontal line and to the right of the midpoint of an angled line, with only the Midpoint running object snap on. The OSNAP and OTRACK buttons on the status bar are active. Object Snap 92
Object Snap Tracking Object Snap 93
Object Snap Tracking Command: C or CIRCLEJ Specify center point for circle or [Undo]: (pause the crosshairs near the midpoint of the horizontal line to acquire it, arid then pause the crosshairs near the midpoint of the angled line to acquire it. Move the crosshairs to the position as shown in the second step until two tracking vectors appear. Pick to locate the center of the circle.) Specify radius of circle or [Undo]: (drag the crosshairs to specify any radius and pick to complete the circle) Command: Object Snap 94
Tracking Once started, Tracking remains active until you press [Enter] at a Next point: prompt The cursor locks to the axis you first move along. If you desire to select another axis, move back to the first point, then move in the perpendicular direction Object Snap 95
Polar Tracking Polar tracking works similar to ORTHO but has a wider range of angle options. ORTHO forces cursor movement to horizontal or vertical only. Polar angles can be selected by user. The cursor snaps to preset incremental angles when a point is being located. Object Snap 96
Polar Tracking ORTHO and Polar Tracking cannot be used at the same time. AutoCAD automatically turns Ortho off when polar tracking is on, and it turns polar tracking off when Ortho is on. Object Snap 97
Object Snap 98
Polar Tracking Turn polar tracking on or off. 1. Select the POLAR button from the status bar 2. Use the [F10] function key. Object Snap 99
Polar Tracking When polar tracking mode is turned on, the crosshairs snaps to preset incremental angles if a point is being located relative to another point. For example, in the LINE command, polar tracking is not active for the first endpoint selection, but it is available for the second and subsequent point selections. Polar tracking vectors are displayed as dashed lines whenever the crosshairs aligns with any of these preset angles Object Snap 100
Object Snap 101
Object Snap 102
Object Snap 103
Polar Tracking Overrides Using polar tracking overrides Allows polar tracking for only one point Works for the specified angle whether polar tracking is on or off. To activate a polar tracking override, type a left angle bracket (<) followed by the desired angle when AutoCAD asks you to specify a point. Object Snap 104
Polar Tracking Overrides The following command sequence uses a 30 override to draw a line 1.5 units long: Command: L or LINE Specify first point: (pick a start point for the line) Specify next point or [Undo]: <30 Angle Override: 30 Specify next point or [Undo]: (move the crosshairs in the desired 30 direction) 1.5 Specify next point or [Undo]: Command: Object Snap 105
Temporary Tracking Object snap tracking has two requirements: running object snap mode must be active and the crosshairs must pause over the selected point long enough to acquire it. Temporary track point can produce tracking vectors without either of these conditions. Object Snap 106
Temporary Tracking To activate temporary tracking, 1. pick the Temporary track point button from the Object Snap toolbar 2. type TT at the selection prompt 3. pick Temporary track point from the Object Snap shortcut menu. Object Snap 107
From Point Selection Option The From point selection option Another tracking tool Can be used to locate points based on existing geometry. It allows you to establish A relative coordinate A polar coordinate, or A direct distance entry from a specified reference base point. Object Snap 108
From Point Selection Option Access the From option by 1. selecting the Snap From button in the Object Snap toolbar 2. selecting From in the Object Snap shortcut menu 3. typing FRO at a point selection prompt. Object Snap 109
From Point Selection Option Example Example shows the center point for a circle being established as a polar distance from the midpoint of an existing line. Object Snap 110
From Point Selection Option Example Object Snap 111
From Point Selection Option Example The command sequence is shown here: Command: C or CIRCLE Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: FRO Base point: MID of (pick line) <Offset>: @2<45 Specify radius of circle or [Diameter] <current>: (pick a radius) Command Object Snap 112
Temporary Tracking Example: temporary tracking can be used to place a circle at the center of a rectangle. The X coordinate of the rectangle's center corresponds to the midpoint of the horizontal lines. The Y coordinate of the rectangle's center corresponds to the midpoint of the vertical lines. Temporary tracking can be used to combine these two points to find the center of the rectangle Object Snap 113
Temporary Tracking Example Object Snap 114