Sometimes, you want one action to execute a second action at the same time. If the relationship [...]]]>

Dynamic blocks, introduced in AutoCAD 2006, are very powerful, but sometimes they can get complicated. One of the more involved features of dynamic blocks is chaining. In this tip, I try to make chaining easy.

Sometimes, you want one action to execute a second action at the same time. If the relationship between the two actions is simple and direct, you can accomplish this easily — without chaining. You just attach two actions to the same grip on the same parameter. When you grip-edit one action, the other happens at the same time.

For example, in this desk set, the desk has a linear parameter and a stretch action attached to the right grip of the parameter. The top-right chair has a move action attached to the same grip. The bottom chair also has a move action attached to that same grip, but the distance multiplier is set to 0.5.

So when you stretch the desk, the top chair moves the same distance, always remaining lined up with the right side of the desk. The bottom chair moves half the distance, always remaining centered behind the desk.

But, your geometry may require more than one parameter.  To activate one action with another in this situation, you use the chaining feature. Note that the secondary parameter, the one whose action will be activated by the primary action, must be a point, linear, polar, XY, or rotation parameter. There are some other limitations, too, but they’re hard to explain, so just experiment.

Remember that you want one action (with its parameter) to activate another action, also with a parameter. So you need two actions and two parameters. Create a chained parameter as follows:

1. Create the block and open it in the Block Editor.
2. Decide on the parameters you’ll need and their actions.
3. Decide which action you’ll grip-edit in the drawing. This is the primary action that will activate the other, secondary, action.
4. Create both parameters first, before creating any actions.
5. Create the primary action and attach it to its parameter (the primary parameter).
6. When you specify the objects for the primary action, include the parameter of the secondary action. This is very important. But don’t include the objects that will be in the selection set of the secondary action.
7. Create the secondary action, attach it to its parameter, and select its objects.
8. Select the secondary parameter, open the Properties palette, and set its chaining property to Yes.

To summarize, the basic principles of chaining are as follows:

• The primary parameter has an action whose selection set includes the secondary parameter in addition to any other objects it will act on. (If the action is a stretch action, the stretch frame also needs to include the secondary parameter.)
• The secondary parameter’s chaining property is set to Yes.

Save your block, close the Block Editor and try out your chained dynamic block. When you grip-edit the primary action, the secondary action will be activated at the same time.

As you drag the primary parameter’s grip, the secondary parameter’s grip moves in response to the result of the primary action. For this reason, chaining is useful when you want to maintain a constant relationship between two components in a block.

In this cover, the handle needs to stay the same distance from the top of the cover. The cover comes in three sizes (the linear parameter has a value set) and has a stretch action. As the cover is scaled, the handle moves up.

Note: Once you’ve perfected your block, you can remove the grips from the secondary parameter, because you don’t need them. In the Block Editor, select the secondary parameter, right-click it, and choose Grip Display > 0.

The move action is attached to the top grip of its linear parameter. As the cover is scaled, this parameter (the secondary parameter) moves up, thereby moving the handle.

The book is only $10 and he’s offering a 40% discount [...]]]>

Edwin Prakoso has written an excellent and thorough e-book on AutoCAD blocks. In 69 pages, he covers the following:

• Creating, inserting, modifying, and replacing blocks
• Creating and using attributes
• Creating annotative blocks
• Creating dynamic blocks, including visibility states, parameters, and constraints
• Extracting data from blocks
• Best practices examples
• Managing and sharing blocks

The book is only $10 and he’s offering a 40% discount with the CN2010 code.  It’s only good until December 31st, which is why I wanted to get this post out to you now. That makes the book only $6!

I suggest that you take a look by clicking this link. (Full disclosure: I make 30% commission.) He also has 2 e-books on Revit, if you’re interested.

I asked Edwin some questions to learn more about him and why he chose this topic:

Q1: Why did you decide to focus on AutoCAD blocks?

I believe that to be productive in AutoCAD, we need to focus on three areas: having good templates, good libraries, and good customizations. Customization need programming knowledge, and not many people can create a program. But AutoCAD blocks are quite simple to create.

I have seen that AutoCAD blocks today can be really useful, not only as reusable content, but also to automate some tasks. By optimizing blocks, we not only become more productive, but also reduce human errors in our design.

Q2: Tell me a little about your background.

I worked in Architecture consultant for a couple of years, then I moved to a building contractor. So I’m familiar with the design process and how we use AutoCAD in that area. I saw that many people tried to create custom programs to be more productive. Then I started to work at an Autodesk reseller, so I had more chances to explore AutoCAD features. I started to see that much of the automation can be done in AutoCAD without any programming. One feature that we can use is AutoCAD blocks. For example, we can use dynamic blocks and data extraction.

Q3: You have 3 e-books, one on AutoCAD and two on Revit. Why did you decide to start writing? Are there any other books on AutoCAD in the pipeline?

I started to write on my blog since 2004. My first blog was written in Indonesian. Some of the readers asked if I could provide the contents in e-book format. It was not easy and expensive to have an Internet connection at that time. I thought it was a good idea. So I decided to also have e-books, especially for materials that can’t be covered in blog posts. At the moment I only have one AutoCAD e-book, but I have plan to cover more about AutoCAD best practices.
Wish me luck!

Good luck, Edwin!

When you insert a block, a Basepoint option appears with the [...]]]>

Blocks and basepoints go hand-in-hand. Knowing how to work with basepoints can make your life much easier. It’s so frustrating to insert a block and have it disappear into outer space because the basepoint is in the wrong location!

The Basepoint option of the INSERT command

When you insert a block, a Basepoint option appears with the Specify insertion point: prompt. When you use this option, you can move the insertion base point of the block to anywhere you want. This option can be really helpful sometimes but I don’t think it’s used very often.

The BASE command

A block library often has one block per drawing. You save each block in its own drawing. By default, the basepoint of a drawing is 0,0. But unless you put the block right at 0,0, you’ll want to change that. (Another option that works is to use WBLOCK and choose to write just the block. Then, the basepoint is taken from the block and is in the right place.)

Use the BASE command in the drawing containing the block to specify the origin of the drawing, which is usually on an object snap somewhere on the block. Then, when you insert the drawing, your basepoint will be right on the block.

The Basepoint parameter for dynamic blocks

Creating a Basepoint parameter

For a dynamic block, the Basepoint parameter  sets a base point for the block. This is useful when you’re turning a block into a dynamic block and want to change the basepoint. You add a Basepoint parameter in the Block Editor, from the Parameters tab of the Block Authoring Palettes, as you see here. The basepoint functions like any other block basepoint.

During insertion of a dynamic block, you can use the Basepoint option as I described earlier.

But you can do something else with dynamic blocks.

While you’re inserting a dynamic block, you can press Ctrl to cycle among the grips if their Cycling property is set to Yes. (By default, it is.) Each time you press Ctrl, the cursor moves to another grip on the block. This lets you visually see the results of each basepoint before you commit to inserting the block.

To check the Cycling property, double-click the block to open the Edit Block Definition dialog box, and click OK to open the Block Editor. Click any grip and open the Properties palette. Look for the Cycling property in the Misc section, as you see here.

Cycling property of dynamic blocks in AutoCAD

If the Cycling property is set to No, click the item, click the drop-down arrow, and choose Yes.

Do you have any other tips for controlling blocks with basepoints?

You start with the new DATAEXTRACTION command, or by starting the TABLE command and choosing the From Object Data in the [...]]]>

When you use EATTEXT, the Attribute Extraction wizard starts. Page 3 of the wizard looks like this:

On the left, [...]]]>

Attributes are labels that you apply to blocks. You can extract them to create a simple database that you can then view in Excel or place in your drawing as a table. You use the EATTEXT command.

When you use EATTEXT, the Attribute Extraction wizard starts. Page 3 of the wizard looks like this:

On the left, you choose a block. On the right, you choose the data you want to extract for that block. However, the display names may not be easy to understand. In the right column, you can change the Display Name (called Alias in some earlier releases) to customize the headings in the resulting file and make them more readable.

Here’s the result:

Now, for example, the last heading is “Date Purchased” instead of PUR_DATE. Much more people-friendly!

I’ve covered aspects of this topic before. In “Tutorial: Display the area of an enclosed figure,” I show how to use fields to create a label that displays an area.

In “Tutorial: Create attributes,” I mention that you can use [...]]]>

You can use fields (AutoCAD 2005 and later) to create automatic labels that provide information about objects.

I’ve covered aspects of this topic before. In “Tutorial: Display the area of an enclosed figure,” I show how to use fields to create a label that displays an area.

In “Tutorial: Create attributes,” I mention that you can use fields in attributes.

In this tutorial, I’ll expand on the idea of using fields in attributes, which are labels attached to blocks. This example shows the use of fields that label geometric parameters of dynamic blocks.

1. Open the Block Editor. (Tools> Block Editor or Blocks & References tab> Block panel> Block Editor.
2. Create the objects for the block.
3. Create the parameter and action you want to label. For example, for a desk, I created a Linear Parameter and a Stretch Action. I renamed the Linear parameter’s label to Length in the Properties palette. If you need further instructions, you can download my complete dynamic blocks tutorial from my “Dynamic blocks tutorial” page.

1. Start the ATTDEF command (Draw> Block> Define Attributes or Blocks & Reference tab> Atrtributes panel> Define Attributes).
2. In the Attribute Definition dialog box, type in a tag name, such as Length. For the Deafult entry, type the text that you want to appear before the value, such as Length: . (Add a space after the colon.) Check the Constant check box so that you won’t get a prompt. The whole point is to make the label automatic. Set the Text Settings section as desired.
3. Then right-click in the Default text box or click the Insert Field button at the right to open the Field dialog box. From the Field Category drop-down list, choose Objects. Then choose BlockPlaceholder as the field name. The Block reference property should be the name of the parameter you used. This is Length in our example. Set the format as desired, and click OK.

Note: The Length property is on the list only because I created a parameter named Length. The other properties are available for all blocks.

1. You’re now back in the Attribute Definition dialog box, which should look like the figure below. Click OK. Place the label where you want it.

1. Save the dynamic block by clicking the Save button in the Block Editor. Close the Block Editor.
2. Back in your drawing, insert the block (Insert> Block or Blocks & References tab> Block panel> Insert). Before you specify the insertion point, you’ll see the following for the label.

After you insert the block, you’ll see the value of the field.

1. After you modify the dynamic block, you’ll need to update the field. In this example, changing the length makes the desk longer. Enter updatefield on the command line to update the field.

Tested in AutoCAD 2009.

Follow these steps:

By placing the attributes where you want them in the title block, you can facilitate the [...]]]>

Tutorial: Create attributes

Attributes are tags, or labels, for blocks. You can use attributes to add any text to a block. For example, attributes are often used to fill in the text in a title block.

By placing the attributes where you want them in the title block, you can facilitate the entering of the text. You can also use fields in attributes, to automate some of the text entry.

You can extract the attributes in a drawing to a table or external file. When you do this, you can use the attributes to create a simple database. You could import it into Excel and manipulate it there.

If you’re using attributes to create title block text, you’ll be working in paper space on a layout. If you’re using them to create labels in the rest of your drawing, you’ll be working in model space.

Follow these steps:

Draw the objects that will make up the block. (If you already have a block and want to add attributes to it, you can explode the block, add the attributes, and recreate the block. You can also open the block in the Block Editor, add the attributes there, and save the changes.)

Choose Draw>Block>Define Attributes (ATTDEF command) to open the Attribute Definition dialog box.

In the Mode section, check one or more of the following:

• Invisible: creates invisible attributes that you can extract, but don’t want to display in the drawing.
• Constant: Sets a constant value so that you don’t need to fill it in each time. You cannot edit this value.
• Verify: Prompts you to verify the value, useful when you have a preset.
• Preset: Inserts a default value, but you can edit it if you set the ATTDIA system variable to 1.
• Multiple Lines: This is also new for AutoCAD 2008 and not shown above. It allows an attribute to contain multiple lines of text. You can also format attributes in a simplified text editor.

In the Attribute section, specify the Tag, which is like a field/column name for the attribute. For example, enter Cost if the attribute will contain cost information. The tag is converted to uppercase and cannot contain spaces or exclamation points.

Enter a prompt, which is similar to the tag, but can contain spaces.

Enter a value to set a default value. In AutoCAD 2008, this is called the Default. To insert a field, click the Insert Field button.

In the Text Options/Settings section, choose a justification, text style, height, and rotation.

In the Insertion Point section, check the Specify On-Screen check box to specify the location of the attribute. Otherwise, enter the desired coordinates.

Check the Lock Position in Block check box to lock the position of the attribute relative to the block, so that you can’t grip edit it and move it.(In AutoCAD 2008, this option is a check box in the Mode section.)

Click OK. At the prompt, specify the location if prompted.

Choose Make Block on the Draw toolbar (BLOCK command) and use the Block Definition dialog box to create the block. When you select the attributes, separately pick them in the order you want them to appear to prompt you for values. You can choose the Delete option to delete the block and attribute items, because you’ll insert the block later, with its attributes.

When you’re ready to insert the block, you can specify attribute values on the command line or in a dialog box. By default, you specify them on the command line. To use a dialog box, change the value of the ATTDIA system variable to 1.

Use the INSERT command to insert the block. If you set ATTDIA to 1, you then see the Edit Attributes dialog box, where you specify values. Otherwise, you see a prompt on the command line. Any default values that you entered are shown in the text boxes.

Enter the desired values and click OK. The block now shows the attributes (unless you set them to invisible).