OSNAP

Today we will try to learn a very important tab called OSNAP – Object Snap.
Object Snap Tab controls running object snap settings. With running object snap settings you can specify a snap point at an exact location on an object. When more than one option is selected, the selected snap modes are applied to return a point closest to the center of the aperture box. Press TAB to cycle through the options.

To understand it better we will take some examples –
1. A Point has a Single Object Snap – A Node
2. A Line has 3 Object Snaps – Two Endpoints and One Midpoint
3. A Rectangle has 8 Object Snaps – Four Endpoints and Four Midpoints
4. A Circle has 5 Object Snaps – One Center point and Four Quadrant Points

Object Snap On turns running object snaps on and off. The object snaps selected under Object Snap Modes are active while object snap is ON.

Object Snap Tracking On turns object snap tracking on and off. With object snap tracking, the cursor can track along alignment paths based on other object snap points when specifying points in a command. To use object snap tracking, you must turn on one or more object snaps.

Object Snap Modes lists object snaps that you can turn on as running object snaps.

Endpoint snaps to the closest endpoint of an arc, elliptical arc, line, multiline, polyline segment, spline, region, ray or to the closest corner of a trace, solid, or 3D face.

Midpoint snaps to the midpoint of an arc, ellipse, elliptical arc, line, multiline, polyline segment, region, solid, spline, or xline.

Center snaps to the center of an arc, circle, ellipse, or elliptical arc.

Node snaps to a point object, dimension definition point, or dimension text origin.

Quadrant snaps to a quadrant point of an arc, circle, ellipse, or elliptical arc.

Intersection snaps to the intersection of an arc, circle, ellipse, elliptical arc, line, multiline, polyline, ray, region, spline, or xline. Extended Intersection is not available as a running object snap.

Intersection and Extended Intersection do not work with edges or corners of 3D solids.

Note – You might get varying results if you have both the Intersection and Apparent Intersection running object snaps turned on at the same time.

Extension causes a temporary extension line or arc to be displayed when you pass the cursor over the endpoint of objects, so you can specify points on the extension.

Insertion snaps to the insertion point of an attribute, a block, a shape, or text.

Perpendicular snaps to a point perpendicular to an arc, circle, ellipse, elliptical arc, line, multiline, polyline, ray, region, solid, spline, or xline. Deferred Perpendicular snap mode is automatically turned on when the object you are drawing requires that you complete more than one perpendicular snap. You can use a line, arc, circle, polyline, ray, xline, multiline, or 3D solid edge as an object from which to draw a perpendicular line. You can use Deferred Perpendicular to draw perpendicular lines between such objects. When the aperture box passes over a Deferred Perpendicular snap point, an AutoSnap tooltip and marker are displayed.

Tangent snaps to the tangent of an arc, circle, ellipse, elliptical arc, or spline. Deferred Tangent snap mode is automatically turned on when the object you are drawing requires that you complete more than one tangent snap. For example, you can use Deferred Tangent to draw a line that is tangent to two arcs, polyline arcs, or circles. When the aperture box passes over a Deferred Tangent snap point, a marker and an AutoSnap tooltip are displayed.

Note – When you use the From option in conjunction with the Tangent snap mode to draw objects other than lines from arcs or circles, the first point drawn is tangent to the arc or circle in relation to the last point selected in the drawing area.

Nearest snaps to the nearest point on an arc, circle, ellipse, elliptical arc, line, multiline, point, polyline, ray, spline, or xline.

Apparent Intersection snaps to the visual intersection of two objects that are not in the same plane but may appear to intersect in the current view. Extended Apparent Intersection is not available as a running object snap. Apparent and Extended Apparent Intersection do not work with edges or corners of 3D solids.

Note – You might get varying results if you have both the Intersection and Apparent Intersection running object snaps turned on at the same time.

Parallel draws a vector parallel to another object whenever you are prompted for the second point of a vector. After specifying the first point of a vector, if you move the cursor over a straight line segment of another object, the point is acquired. When the path of the object you create is parallel to the line segment, an alignment path is displayed, which you can use to create the parallel object.

Select All turns on all object snap modes.
Clear All turns off all object snap modes.

Alright, it’s getting more and more technical and specific, isn’t it? But after all that’s what AutoCAD is all about..! Okay, before you have a spinning head and you start it banging against the monitor, here is good news… Have a break for a day (I need it too!) and Monday we will explore the last TWO (trust me) tabs LWT and MODEL to finish this. Then we can proceed to more interesting and interactive part of Drawing Preparation…!

See you on Monday, stay tuned…!