Cadtales

Creating and using annotative blocks:
Part Two

AutoCAD^® 2008 introduces a new object property called “annotative,” which can be applied to Blocks, Attributes, Text, Dimensions, Hatches, Tolerances and Multileaders. In Part 1 of this article we explained how this property allows you to automate the process of scaling annotations and other features so that they plot or display at the correct size on paper. In this Part 2, we’ll show you how to design and use blocks with Attributes with annotative properties by taking the simple block created in Part 1 and adding three attributes for “block name,” “designation” and “number.”

Let’s start by repeating several important points:

1. Any ordinary block (object) can have annotative properties turned on and scale settings assigned. This affects only the edited instance of the block and not the block definition. However,

2. For a Block to exhibit annotative properties it must be created with annotative properties.

3. For an Attribute to exhibit annotative properties it must be created with Text with annotative properties.

4. Do not scale annotative blocks manually.

Creating a block object
In Part 1, we created a simple block and several viewports in paper space to apply and test the annotative property. Here is the sequence to create those objects: In model space start the Polygon command and create a six-sided polygon using the Edge option to set the edge dimension to 0.25”. Rotate the polygon so that an edge is horizontal and draw a horizontal line from the left node to the right node – dividing the symbol into upper and lower halves. We’ll use this symbol to represent a machine tag (an air handler).

In paper space create a new viewport 0.75” x 0.75”, center the symbol in the viewport and set the Scale to 1:1. Now copy the viewport to make three additional instances to the right and Scale the new viewports to 1/16”, 1/8” and ¼” respectively. Highlight all four viewports, right-click and select Display Locked>Yes. Your drawing should look like Figure 7 below.


Figure 7

Right-click the block in any viewport and select Annotation Object Scale>Add/Delete Scales and set the scale values as shown in Figure 8 below.

Figure 8

CREATING A TEXT STYLE WITH ANNOTATIVE PROPERTIES
As noted in point #3 above, “For an Attribute to exhibit annotative properties it must be created with Text with annotative properties.” So, we’ll need to Format a new Text Style for our Attributes (or turn on the annotative property for an existing Text Style). Open Format>Text Style and select New. Give it the name “ANNO STYLE.” (While you’re here, note the small window below the Styles: listing. It allows you to show “All Styles,” or “Styles in Use,” a useful feature when the drawing has a long list of styles.) Pick an appropriate Font Name. In the Size box check the “Annotative” and “Match text orientation to layout” boxes. In the Paper Text Height window enter the desired text height – use 1/16” for this exercise. Set any remaining features you want and then click the Apply and Set Current buttons and close the dialog box. See Figure 9 below.

Figure 9

Adding attributes to a block
Double click the block to open in the Block Editor (or highlight and type BEDIT). In the Block Editor, put all block elements on layer 0 and set other properties to “By layer” (if you want the block to absorb the properties of the layer on which it is placed in the drawing). Start the ATTDEF command and create three attributes with the following characteristics: See Figure 10 and the notes below.

Figure 10

1. Invisible; Lock position in block; Tag: BLOCK_NAME; Prompt: Block name; Default: ANNO1; Justification: Middle; Text style: ANNO STYLE; check the Annotative box, and ignore the Text height setting – it will be grayed-out and will be set automatically to match scale setting stored in the annotative property. Click OK and place the attribute below the symbol.

2. Visible, Tag: ?; Prompt: Designation; Default: AH (for air handler); other settings same as number 1 above. Click OK and place in the center of the top-half of the symbol.

3. Tag: #; Prompt: Number; Default; 3; other settings same as number 2 above. Click OK and place in the center of the bottom-half of the symbol.

Your symbol block should now look like the sample in Figure 11. Close the Block Editor and save your changes. Click Yes to the Alert box to “update the block definition and all instances in the current drawing.”

Figure 11

Note that all instances of the symbol now contain the new attributes and the block is properly scaled in all the existing Viewports.

Perform additional tests with the new block by inserting in Paper Space and creating new Viewports with different (or unknown) scales, then Zoom to view the symbol. To add this Viewport scale to the scale list, Right-click the block and select Annotative Object Scale>Add Current Scale. See Figure 12 below.

Figure 12

Do you see a productivity and quality benefit to applying annotative properties
to your Blocks, Attributes, Text, Dimensions, Hatches, Tolerances and Multileaders? Call your Hagerman sales representative about software upgrades, training and customization.