How to Create a Dynamic Block in AutoCAD

So you’ve made the first step to an immediate increase in AutoCAD efficiency by creating your first block.  Let’s say you’re an architect, and you’ve created a block represented by a door that you can now quickly add to all your entryways.  This works perfectly — until that door you created for the 2^nd floor bedroom doesn’t fit in the open space left for the front door.  Instead of drawing another door to fit this space, this problem can be overcome through the use of dynamic blocks.  In this guide, I will take you step-by-step through the process of creating dynamic blocks, which you will undoubtedly find useful.

What Are Dynamic Blocks in AutoCAD?

Dynamic blocks introduce a new level of customization to your standard block.  Blocks allow you to utilize repetitive geometry in your drawing, whereas a dynamic block allows you to manipulate specific features of the block.  This makes real-time design changes quicker and easier.  Dynamic blocks are ideal for scenarios where an object will appear in various sizes or configurations within your drawing.

Some practical examples of dynamic blocks:

• A door in an architectural drawing
  • Linear and rotation parameters can be added to allow for editing the position and orientation of the door respectively.
• Windows and furniture
  • Stretch, flip, and rotation actions can be added to furniture blocks for quick edits to size and orientation.

Creating a Dynamic Block in AutoCAD

The path to using dynamic blocks begins with creating standard AutoCAD blocks.  The steps below will help you get started by using the example of a simple rectangle.  Before following the guide below, make sure you’re creating your block in Layer 0.

1. Begin by drawing the rectangle using AutoCAD’s drawing tools.
2. Navigate to the Insert tab found in your top ribbon and click Create Block.
3. The Block Definition dialog box will appear.
4. This is where you will name your block (e.g. door, table, chair, etc.) and select your basepoint. You can always rename the block
   1. Click the Pick Point button to select your basepoint (corner or center of your shape).
   2. Note, if you do not select a basepoint, the block insertion point will default to 0,0,0 coordinates on your drawing.
5. Under the objects column of the block definition dialog box, you will want to Select Objects.
   1. Upon clicking this, the dialog box will be hidden, and you will need to highlight the entirety of your shape.
6. Finally, select either Retain, Convert to block, or Delete under the objects column.
   1. Retain will keep the object block in its original elements (shapes, arcs, etc.).
   2. Convert to block saves the highlighted objects as a consolidated piece.
   3. Delete will save the block to your library and then remove the block from the space in which you’ve drawn it.
7. Press OK to save the block to your library and allow the block editor to be opened.
   1. If the block editor does not open, simply right click on your block and find the block editor option on the drop-down menu.

Dynamic Block Parameters

We will now explore converting your block to a dynamic block.  There are several parameters shown in the block editor (block authoring palette).  For now, we will focus on movement and rotation parameters.  Parameters and actions in combination will allow you to manipulate your block as a dynamic block.

Adding Movement Parameters

For this scenario, you will be moving your shape along the x-axis.  Begin by selecting the Linear Parameter from the block authoring palette.  Because we are repositioning the shape on the x-axis, select the top-left, then the top-right corners of your shape.  From here, you can close the block editor and save your changes to reveal the linear parameter line.

If you have you have your Properties Tab visible, you will see a variety of options that can be edited.  Under the Value Set tab, you can manipulate how you want the movement parameter to affect your shape.  If you have it set to “None,” you will be able to freely move the shape.  Alternatively, the “Increment” option will allow you to move the shape in set amounts along the x-axis.  Also in the properties tab is the Number of Grips.  Grips are the vertices of the linear parameter.  You will likely have two grips, which will allow you to move the shape in either direction on the x-axis.

Now that we have our linear parameter in place, it is time to add an action.  In this case, the Move action will be selected.  Select Move from the actions tab of the block authoring palette, then click on the linear parameter line.  The final step for this action is to select all parts of the block that you want to move.  Since we want the whole shape to move, highlight your shape, then press enter.  At this point, you may want to test the block before adding any more parameters.  Select Test Block from the top ribbon, and make sure your movement action is operable.

Adding Rotation Parameters

Let us now take our shape and add a rotation parameter.  This will allow us to quickly rotate our block around a specified point.  To begin, find Rotation in the parameters tab of the block authoring palette.  The first step is to choose a basepoint.  I find it best to use the same basepoint you used when creating the block (corner or center of shape).  The basepoint you choose will dictate the axis at which your shape will rotate.

Once your basepoint is chosen, a circle will appear with your basepoint at its center.  The point you choose will determine the location of the grip you will use to later rotate your block.  We will then be asked what the default rotation for our block will be, which in this case we will set to 0 by pressing enter.  AutoCAD will then ask how many grips are desired for rotation.  To keep things simple, press enter to use the default setting of one grip.

Let’s now find ourselves back at the block authoring palette and navigate to the actions tab again.  This time, we will select the Rotate action.  Left click on the grip created from the Rotation Parameter to be further prompted to highlight the object(s) that you want to rotate.  For our example, you will select your object and press enter.  Close the block editor, save your changes, and test the block.  Because there are now two dynamic parameters, you will see two grips.  You will be pleased to see that you can now move your shape along the x-axis, as well as rotate it to your liking.

Summary of Dynamic Blocks

Following this guide to create simple dynamic blocks is your first step in tackling your day-to-day headaches in AutoCAD.  Stretch, scale, flip, and alignment are additional parameters that I encourage you to experiment with once you become comfortable with the basics of dynamic block parameters.  With the help of this guide and other resources on our site, the addition of parameter-action combinations to create dynamic blocks is sure to streamline your AutoCAD workflow exponentially.