Making Blocks Annotative
If you have been keeping up with AutoCAD 2008, you know the idea behind Annotative Scaling as it relates to text. The general concept to make it possible to do in one object what once required we use multiple objects. I am of course speaking about copying a piece of text numerous times just so we could plot a drawing at different scales. Personally I would have been happy just to get Annotative Scaling with text in AutoCAD 2008, but the folks at Autodesk were apparently swinging for the fences as they have hit a home run. See, Annotative Scaling isn’t just for text; we can also dynamically scale things like blocks and hatches.
While a large number of blocks are drawn with real units, others are purely for graphical representation and well scale dependent. We typically have to illustrate waterline designs on both normal plan sheets (1″ = 50′), and on at least one overall plan sheet (1″=100′). With that we frequently find ourselves copying our waterline valves multiple times to properly illustrate them at both scales. A scenario such as this is where Annotative Scaling for Blocks can truly shine.
Defining an Annotative Block really isn’t any harder to do than defining a normal block in previous versions of AutoCAD. You will still start by drawing the objects you wish to make a block in your drawing, fire up the BLOCK command, and finally select the objects & specify a base point. The addition you will notice is under “Behavior”. Inside of the “Behavior” group we now have an “Annotative” option. To make it so this block can take advantage of the Annotative Scaling options within AutoCAD 2008, check the “Annotative” check box. With “Annotative” enabled (by checking the checkbox), we can tell AutoCAD to automatically rotate the block to match its viewport by checking the “Match block orientation to layout”. I want to keep my water valve blocks rotated as I insert them into my drawing, and thus will keep that checkbox unchecked (as illustrated).
That’s truly all there is to creating a new Annotative Block. But what if you want to convert an old block from a previous release into an Annotative Block? Exploding it and redefining it is what the hourly employees do when they need a few more billable hours. Smart drafters can simply open the BLOCK command. Contrary to popular belief we can actually do more than create new blocks from this dialog. Simply select the name of the block you want to convert to Annotative from the pull down (where you would traditionally type the name of your block). Select the “Annotative” checkbox as outlined above, and hit [Ok]. AutoCAD will prompt you and ask if you want to redefine the block – answer yes, and your block will now be an Annotative block.
Some good news, and some bad news. Blocks can be both Annotative and Dynamic. Unfortunately if you take a Dynamic Block and use the method I outlined above to convert it to an Annotative block, it will make it Annotative, but also strip ALL of its Dynamic Block Actions and Parameters. Also while you can have an insertion point per Annotative Scale (so one insertion point for 1″ = 50′, and another for 1″ = 100′), you cannot assign different visibility states (Dynamic Blocks) per scale. The functionality introduced in AutoCAD 2008 with Annotative Blocks is something I have been looking for inside of AutoCAD for some time now. While I haven’t redefined my entire block library yet, you better bet I am already thinking of how to best use Dynamic Annotative Blocks to make things easier for my users. Surely with a little imagination you too will be able to see numerous opportunities in your shop as well.
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Here’s something I can’t figure out about annotative blocks and I hope you have an answer:
I insert a block which is a circle that represents a fire extinguisher in plan. I need to put it up against a line that represents the wall. That insertion point could be on any of the 4 quadrant points of the circle. It works fine if you’re only using one scale, but as soon as you change scales in model space, the circle is either on top of the wall or not even touching it. How can I get that block to stay put without defining 4 of the same block with 4 different insertion points? Thanks!
Karen – My apologies for the somewhat delayed response. I may not be visualizing this properly, but it seems like you have a block that gets inserted against a wall. Could you use a single insertion point, and deal with the rotation aspect of things with either a dynamic block or even tool palette? Again I may not be visualizing this properly, but if you e-mail me the block/scenario I’ll be glad to take a look (donnie.gladfelter@thecadgeek.com).
Donnie- I did send you an e-mail with a dwg attachment; I hope you received it.
Karen
The other day I was reading your informative article in the May/June AUGI World and the next day I got my trial version of vanilla AC2008. Annotation was the first feature to jump out at me and I read in Help that this feature could be applied to blocks, but, after searching AUGI fourms and Help, I assumed it was for only block attributes.
Thanks for highlighting this feature!
Donnie,
I think this is a great feature for inserting valves on piping. I do see a drawback however. If you create valves for lets say a 1/8″ scale drawing, then insert them and trim the pipe, the trimming would creat issues for a 1/4″ scale drawing. Since the cad blocks are larger for the 1/8″ scale drawings, trimming the pipe to the block will creat gaps between the pipe and block in the 1/4″ scale drawings. Any suggestions?
@ Shane - The two things that come to mind that may work is using a wipeout or a solid white hatch. Not the AutoCAD standard color white, but the True Color 255,255,255 white. You may be able to trick AutoCAD into making it look like things are trimmed. That is all assuming you are not plotting to a Lines Merge plotter as well.
In response to Karen’s problem of the circle on the wall. Experiment with the ‘align’ option in your dynamic block. You can have a single quadrant as your base and the circle will rotate based on whatever object you are inserting to.
I use blocks for physical entities (air-handling units for example) with attributes to specify the make, model etc. Obviously the geometry of the block is inserted 1:1 (ie non-annotative) but I would like the labels to appear at the appropriate scale for the viewport. I have defined attributes with Annotative set ‘on’ and with a range of scales but when inserted only text with the scale active at the time of definition appears - change the Annotation Scale and the text disappears. AutoCAD’s help/info seems to imply that my aim is possible but how do I achieve this?
Martyn - Admittedly I haven’t had a chance to play around with annotative attribute blocks too much quite yet. The ATTDEF (Attribute Definition) dialog allows you to specify both a text style, and if the attribute is annotative. Make sure you are selecting a text style which is annotative. While the ATTDEF command offers you the option to make an attribute annotative, if the text style is not annotative things don’t seem to work.