AutoCAD 2010/2011/2012 DWG Format

[#1]

How is it possible that the same block has different appearances?

Please check the attached drawing. The blocks are symmetrical, I can't understand why...

[#2]

Why can't it be mirrored? it can be larger if you wanted to even with same name.

[#3]

Hi Janet, It isn't mirrored, because scales and rotation are coincident (please check it yourself in the attached file). Purge, audit, recover... Nothing repaired it. How can I be sure I'm safe from it to happen without me to notice?! I'm sorry I didn't understand what you meant to say with "it can be larger if you wanted to even with same name." What do you mean? Thanks

[#4]

Hi,

one block was inserted sitting on top of the WCS (world coordinate system), the other block was inserted from a UCS with negative world-Z (one block was drawn looking normal onto the table, the other was drawn looking from floor to the table-surface).

- alfred -

[#5]

It was mirrored, yes it was.

A block scale up or down, rotate, mirror still has same name.

[#6 · Accepted solution]

Hi,

>> It was mirrored, yes it was.

In this case: no, it's not mirrored, you can see that within the property window while the block is selected. If it was mirrored it would have got a scalefactor = -1 like this:

In that case here one block is inserted with another UCS or it was rotated (3D-rotated around the X-axis).

- alfred -

[#7]

Good catch, Alfred.

This can be seen using the LIST command.  The "backwards" one indicates:

   Extrusion direction relative to UCS:
                  X=   0.0000  Y=   0.0000  Z=  -1.0000

[#8]

Dear Masters and Mentors,

Yes, in fact I could replicate this unusual situation by inserting one of the blocks using the Bottom view with the UCS aligned with the view.

Thank you for sharing your knowledge.

I doubt that someone has used an inverted view or a non-World UCS, because here we draw exclusively 2D with uniform UCS (drawings are shared and we need to preserve the UCS). These blocks were nested in other bigger blocks (I got them from exploding the main blocks). Would it be possible that some symmetry in the main blocks would have caused this? I mean, is there any other way to do this in another way rather than changing the view or the UCS?

[#9]

Hi,

>> another way rather than changing the view or the UCS?

3DROTATE or setting the UCS to any side-view and then use (normal) ROTATE.

One special command that also would result in that situation is _ALIGN. (for better resolution I have also attached an SWF-anim-file)

But if you (your employees) only work 2D my first guess would by there was someone playing with viewcube or with views.

- alfred -

[#10]

Dear Alfred,

Thank you for the didactic and question-proof answer!