7. Drawing Aids

Drawing Aids

Drawing aids are tools and utilities available to perform task precisely and easily. These aids are available on status bar as a status toggles that means, click on tool to set its status ON and click again to set status OFF. Right click on these tools and select settings option, if available, to open drafting settings dialog box to modify current settings.
These drawing aids work transparently in AutoCAD. Transparent commands are those commands in AutoCAD that can be run within another command without exiting it. Especially these are toggle commands required to set ON or OFF within any command.
Following are the drawing aids available on status bar:

1) Infer Constraints: Set ON/OFF infer constraints. These constraints are parametric constraints and discussed separately in Parametric Ribbon chapter. Right click on this tool then select Settings to open following Dialog Box to show selected parametric constraints in drawing.

2) Snap Mode (Shortcut-F9): Set Snap ON/OFF. Snap means jump and when this option is set to ON, corss-hair (Mouse Pointer) jump on specific spacing to pick accurate point on screen visually. You cannot pick the point in between snap spacing, otherwise, set snap mode to OFF. Generally snap spacing is equal to grid dots spacing to jump mouse pointer dot to dot.
Right click on this tool then select Settings to open following Drafting Settings Dialog Box-

Snap On (F9)- Turn Snap ON/OFF

Snap Spacing: Controls invisible snap (jump) locations that restricts cursor movement to specified X and Y spacing on each intervals.
· Snap X Spacing: Specifies the snap spacing on X-axis (Horizontal) direction. The value must be a positive integer.
· Snap Y Spacing: Specifies the snap spacing on Y-axis (Vertical) direction. The value must be a positive integer.
· Equal X and Y spacing: This option control X and Y values same for both snap spacing and grid spacing.
Polar Spacing: Set jump spacing to used only when polar tracking or object snap tracking is set to ON. This option is available only when “Polar Snap” is selected. If this value is 0, the polar snap distance assumes the value for snap X spacing. This SNAP is useful in diagonal lines creation.

Snap Type: Select snap type from Grid snap or Polar snap. Grid snap can be rectangular (2D) or isometric (3D). Polar snap can work only when polar tracking is ON. Polar tracking is discussed later in this topic.
3) Grid Display (Shortcut-F7): Set Grid display ON/OFF. Grid command is discussed with command line prompts in workspace setup chapter. Here we discuss options available in Dialog Box.

Grid On (F7)- Set Grid display ON or OFF

Grid Style: By default AutoCAD display 3D-style grid, just like a graph paper in model space, paper space and block editor.

· 2D Model Space: ON/OFF 2D style dotted grid
· Block Editor: ON/OFF grid in Block Editor
· Sheet/Layout: ON/OFF grid in paper space
Grid Spacing: Controls the distance between grid points in horizontal and vertical that helps you to visualize the distances.
· Grid X spacing: Specifies the grid spacing on X-axis (Horizontal) direction. If this value is 0, the snap X spacing is used.
· Grid Y spacing: Specifies the grid spacing on Y-axis (Vertical) direction. If this value is 0, the snap Y spacing is used.
· Major Line Every: Specify the frequency of major grid lines (bold) compared to minor grid lines. This is effective only when line grid (3D-style) style is selected. (Turn OFF 2D model space in grid style).
Grid Behavior: Change the grid behavior and grid spacing at the time of Zoom in and Zoom out.
· Adaptive Grid: Turn on dynamic behavior of grid dots spacing at the time of Zoom out. Grid dots spacing adjust automatically to retain on the screen otherwise in case of ‘OFF’ , grid dots spacing stick on specified units to display and it will give an error “Grid too dense to display” when zooming out.
· Allow subdivision below grid spacing: Turn on grid dots display on sublevels at the time of Zoom in. Sublevels means grid within grid. When we zoom in very deep inside the drawing, in general, the main grid dots may be out of screen due to specified grid spacing. In case of sublevels, when we zoom in, grid dots automatically generated dynamically with auto spacing.
· Display Grid beyond Limits: ON/OFF grids outside of limits area.
· Follow Dynamic UCS: Turn ON grid plane to follow the XY plane of the dynamic UCS.
4) Ortho Mode (Shortcut F8)- When this mode set to ON, the cursor can move only horizontally or vertically relative to the UCS (always perpendicular) and the current grid rotation angle. As you draw lines or move objects, you can use ORTHO mode to restrict the cursor to the horizontal or vertical axis. Ortho mode works when you need to specify second point in a command such as line drawing.

5) Polar Tracking (Shortcut F10): Set polar tracking ON/OFF to trace automatically specified incremental angle during the second point specification.

Polar Tracking On (F10) - Set polar tracking ON/OFF.

Polar Angle Settings: Sets the polar increment angle used to display polar tracking when specified increment in angle is occur during point specification. You can specify any angle to trace automatically, for example 45^o, 90^o etc.
You can also specify additional angles to track but they are absolute in nature and not incremental. Click on New button to add new angle in the list or use Delete button to remove any angle from list.
Object Snap Tracking Settings: Set options to use with object snap tracking. You can make selection from orthogonal track (only horizontal and vertical path) or polar angles track (from any angular path).
Polar Angle Measurement: You can select absolute mode of measurement in which angle is measured from default X-axis. If you want to measure angle relatively (with reference to last point) then select relative option.
6) Object Snap (Shortcut F3): Set object snap ON/OFF. Object Snap (OSNAP) is the facility to pick a point of object which has some special properties like center point of a circle, end points of a line, midpoint of a line etc. Following are the different object snap modes through which you can pick a point:

Endpoint : Snaps to the closest endpoint of an arc, elliptical arc, line, multiline, polyline segment, spline, region, or 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.

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. 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. When the aperture box passes over a Deferred Tangent snap point, a marker and an AutoSnap tooltip are displayed.

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.

Parallel: Constrains a line segment, polyline segment, ray or xline to be parallel to another linear object. After you specify the first point of a linear object, specify the parallel object snap. Unlike other object snap modes, you move the cursor and hover over another linear object until the angle is acquired. Then, move the cursor back toward the object that you are creating. When the path of the object is parallel to the previous linear object, an alignment path is displayed, which you can use to create the parallel object. Turn OFF ORTHO mode before using this option.


Note: Use “Select All” button to select all OSNAP options or use “Clear All” option to clear all options choice.
7) 3D Object Snap: Set 3D Object Snap ON/OFF for 3D objects. Not covered in this book.

8) Object Snap Tracking (Shortcut F11): Set Object Snap Tracking ON/OFF. OSNAP tracking means show tracking line from an OSNAP point. To track from an OSNAP point, pause over the point while in command. A tracking vector appears when you move the cursor. To stop tracking, pause over the point again.

9) Allow/ Disallow Dynamic UCS: Dynamic UCS is the feature in which you can temporarily and automatically align the XY plane of the UCS with a plane on a solid model while creating objects. This is the feature used in 3D environment and not covered in this book.
10) Dynamic Input: By default values are entered in command window area. Using dynamic input, you can able to input values where your mouse pointer located on screen that means near the place where you are working. This option controls pointer input, dimension input, dynamic prompting and the appearance of drafting tooltips.

Enable Pointer Input: Set ON/OFF pointer input. This option gives the facility to specify input values near mouse pointer position when a command prompts you for a point, you can enter coordinate values in the tooltip instead of in the command window. Click settings button to change formatting and visibility of coordinates. See preview in Dialog Box.
Enable Dimension Input: Set ON/OFF dimensional input when you need to specify a point. Displays a dimension with tooltip for distance value and angle value when command prompts you for a second point or distance. You can enter value in the tooltip instead of on the command line. This method is also known as Direct Distance entry. Click on settings button to control the input visibility options. See preview in Dialog Box.
Dynamic Prompts: Display command prompt in a tooltip near the cursor. You can enter values in the tooltip instead of on the command line. In a dynamic prompt, press the down arrow key to access options. See preview in Dialog Box.
Drafting tooltip Appearance: Set formatting setting dialog box to modify tooltip appearance. See preview in Dialog Box.
11) Show/Hide Lineweight: Set ON/OFF display of Lineweight (line width) given to any object. When set to OFF, any object that have width using Lineweight will display with default Lineweight.

12) Show/Hide Transparency: Set ON/OFF transparency used with different commands like hatching.

13) Quick Properties: set ON/OFF display of quick properties of selected object. Object properties are discussed later.


Enable Quick Properties Palette: Set Quick properties palette ON/OFF
Palette Display: Display quick properties of all selected objects or only for those objects which have specified properties mentioned in quick properties.
Palette Location: Set quick properties Palette location relative to cursor or static on a fixed point.
Palette Behavior: Set minimum number of rows display in quick properties palette and expand automatically when mouse move over palette.
14) Selection Cycling: Set ON/OFF selection cycling. Selection cycling facilitates you to make selection within overlapping objects. You can control overlapping objects list location as cursor dependent or static. You can also ON/OFF list title bar to save screen space.