ENGT122 - CADI

1. ENGT122 - CADI Chapter 15 - Hatching

2. 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.

3. Example - Hatching • Example of hatching a section view in AutoCAD HATCH

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

5. Hatch Patterns spacing • 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. angle ANSI 31 pattern

6. 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

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

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

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

10. Hatch Patterns Selecting A Hatch Pattern: 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

11. Hatch Patterns All hatch types are available by browsing through the Pattern list. Patterns are loosely grouped by category: • 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. • ANSI… patterns defined by American National Standards Institute. We commonly use ANSI31. • ACAD_ISO… patterns defined by International Standards Organization. Typically use this Pattern (ANSI31).

12. Scale=1 Angle=0 Scale=0.5 Angle=0 Scale=1 Angle=45 Scale=0.5 Angle=45 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. • Angle – rotates hatch with respect to definitionangle. • Scale – scales hatch segment length & line spacing with respect to defined length & spacing.

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

15. Selecting Boundaries Hatch Boundaries can be selected by 2 methods: • 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.

16. Pick Point Pick Point Pick Point 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.

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

18. Island Detection Controlling Island Detection: • The Optionspanel drop-down contains settings for controlling Island Detection. Pick Points Normal Island Outer Island Ignore Island

19. Exercise 1: • Create the RED circles and rectangle shown in A. Then make 2 additional copies as shown in green. • Next setIsland 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

20. 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

21. 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.

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

23. 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

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

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

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

27. 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. AR-B816C ANSI 31 Use Inherit Properties option to hatch the 3rd rectangle. Use Grips to alter the shape…note the Associative behavior.

28. 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.

29. 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 • Pattern • Angle • Scale

30. Final Notes For future assignments use the following settings: • Section lines (ANSI31 pattern – adjust angle as necessary): • Line weight = 0.35 mm • Color = Cyan • Linetype = Continuous • Cutting Plane Lines: • Line weight = 0.7 mm • Color = Magenta • 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.

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32. The End!