LT Unlimited

Display grips in blocks

Normally, when you select a block or external reference, you only get one grip, at the insertion point. (You'll also get grips for unlocked attributes, but these days I hope they're the exception rather than the rule.)

If for some reason, though, you want more grips, set GRIPBLOCK to 1. Then you'll see all available grips, just as if they were regular objects in the drawing. You can't do anything with these grips, besides the standard "move" action, and if you have a lot of blocks (or a few complicated ones) they can clutter your display pretty quickly.

But knowledge is power, right? And now you know one more way to control grip display in AutoCAD LT.

Lock Attribute Position in Blocks

First off, thank you to everyone who attended yesterday's webcast on Block Attributes. We had well over 200 attendees -- an excellent turnout! If you missed it, we'll be posting it to the AutoCAD LT Training page soon.

One of the things I talked about yesterday is what it means to lock an attribute's position in a block. The image below shows a block with 3 attributes. Two are locked, one is unlocked. Can you tell which is which?
The "View Title" and "Sheet Number" (a.k.a. 1) are locked, but the "Scale" is not.

When and attribute's position is locked, the only way to relocate the attribute is to use a dynamic parameter/action combo.

When it's unlocked, the attribute's grips are displayed when you select the block, and you can use them to reposition the attribute. You can't include unlocked attribute in a dynamic action's selection set.

Personally, I prefer to lock my attributes. It's cleaner, visually, and enables me to really control the behavior and location of the attribute.

You can set an attribute to be locked or unlocked when you create it, or you can change it later from the Properties Palette.

Breakline Dynamic Block -- Part 4

It's time to wrap up our tour through the process of creating a dynamic block breakline. In the last three, posts, I walked you through the steps for adding a variety of parameters and actions to create stretch and rotation options.

Before I post the video, I want to add a few little clean-up notes:

1. In Part 3, I initially forgot to say that you need to include the linear parameters in the rotation action's selection set. Do NOT include the stretch actions -- just the parameters. If you don't, when you rotate the block, the stretch grips get left behind. (Oops.) If you include the stretch actions in the rotation action's selection set, weird things will happen when you try to use the block. A good rule of thumb is that if something odd is happening to your block the first thing you should check is whether you've included actions in selection sets.
2. You can (and probably should) also add a Base Point parameter to your block to define its insertion point. With Base Point parameters, you don't have to worry about creating your block at any particular coordinate location. They don't have any actions; just plop one in at your desired insertion point.

Okay, here you go:

If you can't get to YouTube, you can download the video here. (MP4 format, 3 MB)

Breakline Dynamic Block -- Part 3

Today's post continues the creation process for a breakline dynamic block. Here's where we left off last time, with independent stretch actions on the left and right ends of the breakline:

The last thing I want to do is add a rotation action. Sure, you could use the regular rotate command, or grip-edit the block, but having an action to rotate the breakline seems faster to me, since you've already got the block selected to change its end points. If you don't want to rotate your breakline with an action, you certainly don't have to.

As usual, I'll start by adding the rotation parameter. I'll pick the center, the radius, and the default rotation angle. Since our breakline starts out horizontal, that default angle is 0. Non-zero default angles come in handy when your default state is not horizontal. Then, any rotation can be done incrementally, instead of having to do the math back to zero. Anyway, here's what it looks like:

For a rotation parameter, the grip location is fairly arbitrary. Just put it somewhere where it'll be obvious what it affects. And there's that exclamation point again -- I'll double click on it to create the rotate action.

After double-clicking, the first prompt is to select objects. That's because, unlike linear parameters, rotation parameters can have only one action type. So there's no need to prompt you with a choice.

I select the polyline and the two distance parameters (so that the stretch grips rotate with the line), and I'm done.

Now I have a dynamic block with 3 possible actions -- stretch the left end, stretch the right end, and rotate.

On Monday, I'll post a video showing the creation process start-to-finish.

Breakline Dynamic Block -- Part 2

In the last post, I started the process of creating a dynamic block breakline, beginning with stretching the right end of the line. Here's where we left off:

Now let's go get the other side.

I prefer to have the left and right sides of the breakline stretch independently. Sometimes, things just aren't symmetrical. So to stretch the left side, I'll just repeat the process from last time.

1. Create a linear parameter from the center of the breakline to the left end.
2. Double-click the exclamation point and choose Stretch.
3. Select the left-hand grip as the associated parameter point.
4. Draw the stretch window around the left end of the breakline.
5. Select the polyline as the object to stretch.
6. Select the parameter and use the Properties palette to set the number of grips to 1.

And here's what I get:

If you like shortcuts (and who doesn't?), there's a "Linear Stretch" item on the "Parameter Sets" tab of the Block Authoring Palette. It does steps 2, 3, and 6 for you.

Maybe in your world, though, your breaklines are always symmetrical. In that case, there's no need for a second parameter. Here are two ways you can create symmetric stretching with one parameter and two actions.

1. Use a stretch action on the Distance 1 parameter with either a distance multiplier of -1 or an angle offset of 180 degrees.

This method uses the same parameter and associated point as the first stretch action, but the stretch window is on the other end.

The other difference is in the action's properties. When the right end moves right, the left end needs to move left (and vice versa). To make this happen, you can either give the action a distance multiple of -1, or an angle offset of 180 degrees. It doesn't matter which one you use.

Now we have a block with one grip that moves both ends.

2. Adjust the Distance1 parameter to have 2 grips and a base location of "midpoint", and use the action from method 1.

Until now, we've been stretching linear parameters from what's called the "startpoint", or the first defined point of the parameter. But you can also have linear parameters that stretch symmetrically from their midpoint.

First, I'll adjust the location and properties of the Distance1 parameter.


Notice that the exclamation point is back, and that the blue "x" is still in the center of the polyline. (Before, it was attached to one end of the Distance1 parameter.)

Next, I'll create the stretch action for the left side of the breakline, making sure that the "associated point" is the left end of the parameter.

I don't have to do anything special to the action -- it automatically moves the correct way.

In this configuration, moving either grip also adjusts the other side, so that the breakline once again stays symmetric.

In the next post, I'll show you how to add the optional rotation action and parameter.

Breakline Dynamic Block -- Part 1

Last week, I posted about a dynamic block breakline that I'd created to mimic the behavior of the Express Tool.

This week, I'll go through the steps to create it, showing you a few dynamic block tips and tricks along the way.

Step 1 is to create your geometry. I just drew a polyline in the shape of my default breakline.

Step 2 is to create a parameter. A parameter is essentially a type of property -- you can have parameters that define lengths, angles, positions, etc. The first parameter I'm going to create is a linear parameter. It simply defines the distance between two points.

So "Distance1" is now the distance between the center of the breakline and one end. (Notice that I held the end of the parameter back from the end a little. This lets the breakline hang over the edge without having to measure it each time.)

The exclamation point means that the parameter's not done -- it needs an action. Actions control changes in parameters.

Double-clicking on the exclamation point brings up the actions to choose from. For a linear parameter, you can choose Array, Move, Scale, or Stretch. Today, I want Stretch.

Next, I have to pick the parameter point to associate with this action. In other words, should moving the right-hand arrow change the geometry, or should the left-hand arrow? Stretching from the center wouldn't make much sense, so we'll use the right-hand arrow.

Next, I'm asked for a stretch frame. I need to window around the objects and points I want to stretch -- in this case, the right end of the breakline.

Unlike with the regular stretch command, though, drawing the window doesn't mean you're done. In the Block Editor, you still need to select the objects to stretch. This is nice, because it gives you more control over the objects in your dynamic block.

Once I select the polyline, the Action appears next to the parameter. The exclamation point doesn't go away, though, because there's still a parameter grip that doesn't have an action.

If you're on an earlier version of AutoCAD LT, your action will look like this instead:

I don't actually want to use that other grip, so I'll select the parameter and use the Properties palette to set the number of grips to 1.

Testing the block shows me that my stretch action is working as intended. Tune in next time for options for stretching the other end of the breakline.

When this is done, I'll post a video showing the creation process start-to-finish.

Quick Way to Close the Enhanced Attribute Editor

In the old Attribute Editor, the only ways to get out of it were to either click the OK button or Tab over until it was highlighted and then press Enter. Not too bad, unless you're A) a keyboard junkie and/or B) editing the first attribute in a block that has twenty.

But in the Enhanced Attribute Editor (long available in AutoCAD, now included in AutoCAD LT 2010), there's an even easier way: Ctrl+Enter.

Just like the Mtext Editor, that handy two-key shortcut closes the dialog and saves your changes. Of course, clicking OK and Tab-Enter-ing over to OK still work too, but in my opinion Ctrl+Enter is faster than both.

Action Bars in the Block Editor

Prior to AutoCAD LT 2010, it could be difficult to tell in the Block Editor which actions, parameters, and objects were related. For example, look at this steel beam section, as seen in the AutoCAD LT 2009 Block Editor:

It's a mess -- actions everywhere, labels overlapping...yes, it could be laid out better, but even so there's no easy way to tell which actions affect which parameters.

Now look at the same block in the AutoCAD LT 2010 Block Editor:

Ahh...much better! Now, all the actions have been consolidated into Action Bars, so that all the actions for a given parameter are nicely grouped together. The icon tells you what type of action it is, and hovering over an icon gives you the action's name and highlights its parameter.

Even better, you don't have to do anything special to use Action Bars -- all your dynamic blocks will automatically display this way when you edit them in LT 2010.

Attributes and Flip Actions in Dynamic Blocks

The last time I overhauled a block library was in 2007, when dynamic blocks were still new to LT. Back then, it was a bit of a challenge to have a "left hand" and a "right hand" version of a block containing attributes, because the attributes maintained their justification through a flip action. (So if you flipped a block, then edited the attribute value, you might end up with text in unexpected places.)

The workarounds I came up with were either to use center-justified attributes (not always practical), or to use visibility states for the left and right versions (also not ideal, since you had to enter the attribute value twice).

LT 2008, though, introduced multiline attributes which adjust their justification when flipped. It's an extra click to access the value, since you have to launch the attribute editor and then the multiline attribute editor, but I think the flexibility of the multiline attribute (and getting rid of the visibility states) makes it worth it.

What do you think? How do you handle "left" and "right" versions of blocks?

Re-order Attributes in Blocks

Among the new-to-LT block attribute tools in LT 2010 is the Block Attribute Manager. You can find it on the Attributes panel of the Insert tab as "Manage", or at the command line as BATTMAN. (And if you just started singing the theme song, you're not alone.)

The Block Attribute Manager helps control the order of your attributes so that you can enter data in a logical way. For example, this block has its attributes out of order -- I'd like to enter Line 1 first, then Line 2, and so on, but right now they're mixed up.

(Yes, this attribute editor is different from the one available in LT 2009 and earlier. No, I haven't posted about it yet...but I will soon.)

To fix this, I'll run BATTMAN.

 

The "Move Up" and "Move Down" buttons rearrange the attributes until they're in the order you want.

"Edit" launches the Edit Attribute dialog, where you can make changes to the attribute's overall properties, including its default value and prompt.

"Remove" deletes the attribute from the block definition.

"Sync" applies your changes to all block instances currently in the drawing.

You can use the pull-down at the top to switch between block definitions to make changes to the order of their attributes.

Along the bottom, "OK", "Cancel", and "Help" are pretty straightforward.

"Apply" saves your changes without closing the dialog so you can continue to manage attributes for that block or others.

"Settings" brings up a small dialog that has mostly to do with which properties are displayed in the main dialog window (like Tag and Prompt above). It helps you to distinguish between attributes, in case you have some with similar properties.

Two options you'll want to pay closer attention to are the ones circled in red. "Emphasize duplicate tags" shows you when you have two or more attributes in a block with the same tag. This is generally considered bad practice, because it can cause some unexpected behaviors.

"Apply changes to existing references" does exactly that -- if you uncheck the box, existing blocks aren't modified unless you use the Sync button in the main dialog.

Once I've finished my rearranging and closed the Block Attribute Manager, I can go back to my block and see the correct attribute order.