The previous exercise showed the effect that freezing a layer has on blocks. When the layer of a block is frozen, the entire block is made invisible, regardless of the layer assignments of the objects contained in the block. Keep in mind that when blocks are on layers that are not frozen, the individual objects that are a part of a block are still affected by the status of the layer to which they are assigned.
You can take advantage of this feature by using layers to store parts of a drawing that you may want to plot separately. For example, three floors in your apartment building plan may contain the same information, with some specific variation .on each floor. In this case, you can have one layer contain blocks of the objects common to all the floors. Another layer contains the blocks and objects specific to the first floor, and additional layers contain information specific to the second and third floors. When you want to view or plot one floor, you can freeze the layers associated with the others. With respect to Freeze/Thaw visibility, external referenced files inserted usin the external reference (Xref) cemmana also act like Dlocks. For example, you can Xref several drawings on different layers. Then, when yeu want to view a particular Xref .rawin” yeu can freeze all the layers except the ene containing that drawing.
In larger projects, you may not want to combine all of your floors into one file, but instead combine different types of data such as electrical, mechanical, interior, site, and lease data. When you want to plot an interior plan, for example, you turn off or freeze layers associated with other disciplines. In fact, this is how the San Francisco Main Library project was organized. However, you may still use common data such as structural grids, columns, elevator core, and stair drawings as part of all your floor plan files.
Using layers and blocks in these ways requires careful planning and record keeping. If used successfully, however, this technique can save substantial time when you’re working with drawings that use repetitive objects or that require similar information that can be overlaid.
Take Control on Region
If yc,;11vork with extremely large files and !:eg<-:ctimes be •..ome a problem, you canconrrol regeneration by setting tl,e Regenmode ‘system vanable to 0 (zero). YOu cai, als use the Rzgenauro commanc’ to accomplish the same thing, by typir Reger: auto.J Off.
If you then issue. command that norrnallv triggers a regen, AutoCAD will give the message Regen queued. For example, when you globally edit attributes, redefine blocks, 3W frozen la jeIS, change the Ltscale setting, or, in some cases, change a text style, you will we. the Rellen queued mcssabe. You can “queue up” regens then at a Line choose. You can issue a regen to update all the changes at once by choosing VIew> lsegen, or by typing Re.J. This way, only one regen occurs instead of severaL By taking control of when regens occur, you can reduce the overall time you spend editing large.
Using Hatch Patterns in Your Drawings
To help communicate your ideas to others, you will want to add graphic elements that represent types of materials, special regions, or textures. AutoCAD provides hatch patterns for quickly placing a texture over an area of your drawing In this section, you will add a hatch pattern to the floor of the studio apartment unit, thereby instantly enhancing the appearance of one drawing. In the process, you’ll learn how to quickly update all the units in the overall floor plan to reflect the changes in the unit.
View Selections Temporarily closes the dialog box and then highlights the objects that have been selected as the hatch boundary by AutoCAD.
Inherit Properties Lets you select a hatch pattern from an existing one in the drawing. This is helpful when you want to add a hatch pattern that already exists, but you do not know its name or its scale, rotation, or other properties.
At the very bottom of the column of options is the Composition button This option lets you determine whether the hatch pattern being inserted b associative or nonassociative. An associative hatch pattern automatically changes to fill its boundary whenever that boundary is stretched or edited.
Using the Advanced Hatch Options
AutoCAD’~ Boundary Hatch command has a fair amount of intelligence. As you saw in the last exercise, it was able to detect not only the outline of the floor area, but alsO the outline of the toilet seat that represents an island within the pattern area. If you prefer, you can control how AutoCAD treats these island conditions and other situations by selecting options available when you click the Advanced tab in the Boundary Hatch dialog box .
In addition to controlling the Island Detection feature of hatch patterns, the Advanced tab lets you fine-tune other aspects of hatch pattern creation.
Island Detection Style
The Island Detection Style button group at the top of the dialog box controls how nested boundaries affect the hatch pattern. The graphics in this button group show examples of the effect of the selected option. The Island Detection Style options include the following:
Normal Causes the hatch pattern to alternate between nested boundaries. The outer boundary is hatched; if there is a dosed object within the boundary, it is not hatched. If another closed object is inside the first closed object, that object is hatched. This is the default setting.
Outer Applies the hatch pattern to an area defined by the outermost
boundary and by <;lnyboundaries nested within the outermost boundary. Any boundaries nested within the nested boundaries are ignored. Ignore Supplies the hatch pattern to the entire area within the outermost boundary, ignoring any nested boundaries
The Boundary Hatch command can also create an outline of the hatch area using ‘one of two objects: 2D regions, which are like 2D planes, or polyline outlines. Boundary Hatch actually creates such a polyline boundary temporarily, to establish the hatch area. These boundaries are automatically removed after the hatch pattern is inserted. If you want to retain the boundaries in the drawing, make sure the Retain Boundaries check box is checked. Retaining the boundary can be useful in situations where you know you will be hatching the area more than once, or if you are hatching ‘complex area.