ENGT122 - CADI Chapter 15 - Hatching

What is Hatching? Hatching refers to filling an enclosed boundary with a repetitive pattern of formatted line segments. Hatching in AutoCAD is the same as creating Section Lines in drafting. Typically used to identify cut region of a part in a Section View of a detail drawing. Also used to distinguish parts or identify materials in sectioned assembly drawings.

Example - Hatching Example of hatching a section view in AutoCAD HATCH

DEMO 1: Load file Demo1.dwg. Create a quick hatch for reference.

Hatch Patterns AutoCAD provides numerous predefined hatch patterns. Each hatch pattern is defined by individual line segments with a specified pattern, angle, and spacing. For convenience, the line segments in each hatch are stored and treated as a group. EXPLODE will break the hatch into individual segments. pattern spacing angle ANSI 31

Hatch Boundary Hatching is typically performed on drawing regions completely enclosed by a boundary – Hatch Boundary. The Hatch Boundary may consist of lines, arcs, circles, or other entities. AutoCAD does not require the objects comprising a Hatch Boundary to be connected point to point. Any intersecting entities which form an enclosure will work. Hatch Boundary

Creating a Hatch Command to create hatch patterns; HATCH Uses contextual change in ribbon menu to apply the hatch and choose options. Uses contextual change in ribbon menu to apply the hatch and choose options. Boundary defined by; Boundary defined by; Selecting a location within an enclosed region; or by Selecting a location within an enclosed region; or by Selecting boundary objects. Selecting boundary objects. Preview of hatch pattern is displayed as you work. Preview of hatch pattern is displayed as you work.

HATCH HATCH can be invoked by 3 methods; Command: HATCH Command: HATCH Ribbon: Home > Draw > Hatch Ribbon: Home > Draw > Hatch Draw Toolbar: Hatch Draw Toolbar: Hatch All result in a contextual change in the ribbon menu which will display the Hatch Creation tab.

HATCH Properties Panel Controls Several Properties of the Hatch: Hatch Type Hatch Pattern Color Hatch Background Color Hatch Angle Hatch Pattern Scale Hatch Transparency

Hatch Patterns Hatch Type in Properties Panel sets the hatch pattern type. Pattern – Selects from industry standard hatch patterns supplied with AutoCAD. Solid – Selects a solid fill. Gradient– Selects a gradient transition between 2 colors. User Defined - Creates a user defined pattern “on the fly”. Covered in CAD III Selecting A Hatch Pattern:

ANSI… patterns defined by American National Standards Institute. We commonly use ANSI31. ACAD_ISO… patterns defined by International Standards Organization. Hatch Patterns SOLID – solid fill hatch AR-… architectural patterns. GR_... Gradient hatches USER DEFINED – custom pattern created on the fly. Plus a variety of other AutoCAD Patterns. Typically use this Pattern (ANSI31). All hatch types are available by browsing through the Pattern list. Patterns are loosely grouped by category:

Hatch Pattern Definitions Effect of Angle & Scale: The hatch pattern line segment lengths, spacing, and angle are predefined. However, Angle and Scale can be altered. Scale=1Angle=45 Scale=1Angle=0 Scale=0.5Angle=45 Scale=0.5Angle=0 Angle – rotates hatch with respect to definition angle. Scale – scales hatch segment length & line spacing with respect to defined length & spacing.

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DEMO 2A: Load file Demo2.dwg Show various predefined patterns, solid, and gradient. Show effect of Angle and Scale. Show Exploding Hatch.

Pick Points – pick inside a closed boundary. AutoCAD automatically selects objects from the smallest enclosure surrounding the picked point. Select Objects – requires selecting the bounding objects of region to be hatched. Selecting Boundaries Hatch Boundaries can be selected by 2 methods:

Selecting Boundaries Pick Points: Constructs a boundary from the smallest enclosure surrounding the picked point. Uses island detection to remove regions completely enclosed within the boundary. PickPoint PickPoint PickPoint

Selecting Boundaries Pick Points: Multiple pick points can be used to add islands or additional areas to the hatch region. PickPoint PickPoints

Island Detection Controlling Island Detection: The Options panel drop-down contains settings for controlling Island Detection. Normal Island Outer Island Ignore Island Pick Points

Exercise 1: Create the RED circles and rectangle shown in A. Then make 2 additional copies as shown in green. Next set Island Detection to Normal, then: Use Pick Points to hatch each figure as shown in B using the ANSI31 hatch pattern. Use the Scale option to get a reasonable hatch spacing. Figure A Figure B

Exercise 2: Make 3 copies of the circle pattern as shown in A. For each copy, re-issue the Hatch command and use a single Pick Point with the correct Island Detection Option to hatch each figure as shown in B. Use the ANSI31 hatch pattern and the Scale option to get a reasonable hatch spacing. Figure A Figure B

Selecting Boundaries Select Objects Constructs a boundary from selected objects. Does not recognize interior objects unless they are selected as well. More limiting than Pick Point method – not all hatch patterns can be achieved.

Selecting Boundaries Select Objects Examples of Select Object Method if Island Detection is set to Normal. Select Object

Exercise 3: Make 3 copies of the circle & rectangle pattern as shown in A. With Island detection set to Normal, use Select Objects to hatch each figure as shown in B. Use the ANSI31 hatch pattern, and use the Scale option to get a reasonable hatch spacing. Figure A Figure B

Miscellaneous Hatch Options Remove Boundaries – allows boundaries such as islands to be removed from selection set.

Miscellaneous Hatch Options Match Properties – allows hatch pattern properties from a hatched object to be transferred to other selected objects. Create Separate Hatches for multiple selections, each hatch is treated as a separate object. Associative – hatch pattern will update if boundary geometry is changed.

DEMO 3: Load file Demo2.dwg Show Associative vs. Nonassociative Hatch pattern. Show Create Separate Hatch Show Inherit Properties

Exercise 5: Create 3 rectangles and hatch 2 of them with the pattern indicated…don’t worry about color but note the angle on last. ANSI 31 AR-B816C Use Inherit Properties option to hatch the 3 rd rectangle. Use Grips to alter the shape…note the Associative behavior.

Hatching Around Text For hatching, AutoCAD treats text like any other object. The same rules for Island Detection and Selection still apply. If Object Selection is used, the text as well as the geometry must be selected to prevent an overlay.

Editing Hatches Methods to initiate a Hatch Edit: Simply select the hatch and the Hatch Editor menu will appear for editing. Double-click on the hatch and the Quick Properties menu will display allowing key values to be modified such as: Color Color Pattern Pattern Angle Angle Scale Scale

Final Notes For future assignments use the following settings: Section lines (ANSI31 pattern – adjust angle as necessary): Line weight = 0.35 mm Line weight = 0.35 mm Color = Cyan Color = Cyan Linetype = Continuous Linetype = Continuous Cutting Plane Lines: Line weight = 0.7 mm Line weight = 0.7 mm Color = Magenta Color = Magenta Cutting Plane Linetype = Hidden or Phantom with CELTSCALE adjusted to get proper segment lengths. Cutting Plane Linetype = Hidden or Phantom with CELTSCALE adjusted to get proper segment lengths. View Arrows = Continuous lines. Use Polyline to create arrow. Length to width ratio = 3. View Arrows = Continuous lines. Use Polyline to create arrow. Length to width ratio = 3.

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The End!