Mirrored annotative dynamic block flips back after re-open

Hi! I've been experimenting a bit with annotative dynamic blocks, specifically with the purpose of creating annotative section arrows.

 

I've created an annotative block containing the arrow drawing and a single attribute definition for the lettering (A, B, C...) that does NOT have locked position so that the user can be able to move the letters.

 

Everything works as expected except one thing: when testing I've been mirroring the block to get one section arrow at each side of the plan. The text even stays correctly orientated (and if the section is diagonal I can go into the enhanced attribute editor and specify the text rotation). The problem occurs when I save and re-open the drawing, then it seems that AutoCAD forgot that the block was mirrored, and it has been flipped back and moved around.

 

I am pretty sure this doesn't have anything to do with Annoreset or some variable like that, but I'm not sure.

 

I was wondering if anybody else had a similar issue or can recreate the problem. I'm guessing this is just one of those AutoCAD things... and that the solution would be to create one block for each side, and don't ever mirror them. Rotating and scaling the blocks work just fine.

 

Thanks in advance. I'll attach my file.

 

section arrow.zip

Make it a dynamic block. There is a simple example attached. Warning, the example is in imperial units, inches. I normally use my example both as section arrows and elevation callouts. This one is an elevation callout. The section arrow will of coourse, have a section line. I am not sure how to build it, I didn't do this one. This block is not annotative though. The attributes, do not rotate or flip.

 

Use a flip parameter/action, and a rotation parameter/action. Forget the mirror thing. It works best inside the block definition. Mirroring dynamic and/or annotative blocks can be problematic. Apparently it just adds a truckload of overhead math for AutoCad to do in the negative to keep the block integrity when mirrored.

 

I have also found that editing a block definition with something as simple as a hatch scale change can cause reversion to the native state of the block in the previously inserted instances of the block. I have not had it revert mirrored blocks, but I have had a bunch of dynamic blocks (stretch) all revert back to the native length in the definition. I wonder if the enhanced attribute editor can cause the reversion too.

Flip block.dwg

Edited May 10, 2014 by Dana W

Thanks. I had a faint hope that there might have been some system setting or something that I had missed but I guess not. Will make a dynamic block.

Thanks. I had a faint hope that there might have been some system setting or something that I had missed but I guess not. Will make a dynamic block.

Well, it is supposed to work the way you were doing it, but sometimes the program code loses track of what it was doing. It would take pages and pages to explain how a computer program processes vector graphics information, and how it might lose some of it.

 

Lets just say we find a work-around. Actually though, the advent of dynamic blocks has rendered the mirroring of blocks after insertion, to the status of a work-around.