2012 weirdness with elevation and extrusion

[Jack_O'neill]

Clipped from the help file:

 

You can use LIST to display and then copy the properties of selected objects to a text file.

The text window displays the object type, object layer, and the X,Y,Z position relative to the current user coordinate system (UCS) and whether the object is in model space or paper space.

LIST also reports the following information:

 

• Color, linetype, and lineweight information, if these properties are not set to BYLAYER.
  
• The thickness of an object, if it is nonzero.
  
• Elevation (Z coordinate information).
  
• Extrusion direction (UCS coordinates), if the extrusion direction differs from the Z axis (0,0,1) of the current UCS.
  
• Additional information related to the specific object type. For example, for dimensional constraint objects, LIST displays the constraint type (annotation or dynamic), reference type (yes or no), name, expression, and value.
  

 

You can list them from any angle you wish with the orbit command, and the numbers don't change. When you hit Left or Right, it changes the ucs accordingly. The isometric view don't change the ucs either, but if you hit the Bottom button, the positive x axis coordinate becomes a negative x axis coordinate.

[Jack_O'neill]

When you use those buttons, 0,0,0 stays in the same place but the ucs rotates about it in the appropriate axis.

[charleyy]

mr o'neill-

thanks for info, etc

of course, i know what UCS does, and if i want to change the UCS *I* want to change it, not have that stupid UCSFOLLOW crap on (i've asked in a forum before, but did not get an answer on *why* that would cause *other*, separate viewports to flip around/zoom extents when operating in *another* viewport, bug?)

when i change a view to work on something 3D (which this was NOT supposed to be), then i change my UCS as *I* want to change it, not depend on the UCSFOLLOW crap...

the *REAL* problem (which was not evident in the test file i attached, it only had some of the symptoms) was that it was apparently throwing entities (not just blocks) to a semi-random negative elevation in a strictly 2D drawing, NO 3D entities made, inserted, or intended...

take your point about the variable X/Y/Z values depending on view (although I still think that is stupid: if i draw an element at 100, 100, 100, i want to move, stretch, etc that entity based on my WORLD coordinates and the absolute Z value... i find it easier to keep that world coordinate system straight in my head and move everything relative to that (*of course* i use UCS when drafting some non-orthogonal objects, but that is VERY rare where we are talking walls/floor/ceilings which are almost always at right angles with no 'organic', weird, non-linear shapes)

in any event, that still does not explain why the stupid little example file i uploaded LISTs the objects as being extruded either 1" or -1"...

thanks again for your patient replies

charley at svmarchitects dot com

[Jack_O'neill]

Normally (in world UCS), if you create a shape and type in "extrude" that will happen in the z axis. The 1 or -1 for extrusion direction is an indication that the current ucs is not the same as the world ucs and has nothing to do with something having actually been extruded. I'm not sure what purpose this serves now except to confuse people. I suppose you could use it to check for objects that were drawn on a UCS other than world, but other than that it serves no purpose I know of. There are folks here that know lots more about programming than I do, so they may know a use for it.

 

Those view buttons though don't just change the view, they also change the ucs. The iso view buttons don't change the ucs. The pic below might help explain. Pictures are worth 1000 words. The first side is viewing your drawing from SW iso, after having hit the TOP button first. The image on the right is after hitting the LEFT button, then immediately following with a SW iso. See how the ucs icon has changed? That's why you see the change from zero to some strange z axis number.

[nestly]

I think Jack is spot on.

 

The "Extrusion direction" does NOT mean the object are extruded, or have ever been extruded, it merely indicates which direction they "would" go if you did extruded them.... ie which direction was "up" or "postive Z" when the object was created.

[charleyy]

well, the 'extrusion' indication sure fooled me !

as you mentioned *WHY* would they put that in like that ? ? ?

maybe it is meant to indicate something else, but it sure looks like it is telling me that something is extruded when it says the extrusion is 1" or -1"...

*PLUS* when i tried - in the original file where the entities *ARE* at negative elevations- to CHANGE/PROP/ELEV, it was giving me the 'can not move, entities have differing Z values' message, *that* made me wonder what the hell was going on, and led me to suspect the *apparent* extrusion it was telling me...

makes no sense to me...

(oh, and i *still* want to have a 'constant' WCS in my views, i am moving/editing things relative to *that*, not whatever random UCS happens to come along...)

sorry, i'm old school and these damn autocad programmers 'improving' things need to just get off my lawn ! ! ! hhh

[Jack_O'neill]

Well, it's not random, it's done by design so you can draw on all six sides of an object without having to manually rotate your object or the ucs. I do a lot of 3d drawing, so I'm moving the ucs around all the time. If you get confused and want to quickly get back to something you are sure of, type in "plan" on the command line. That will offer you the chance to go to the current ucs, the world ucs or any of the ones you've created and saved.

[nestly]

(oh, and i *still* want to have a 'constant' WCS in my views, i am moving/editing things relative to *that*, not whatever random UCS happens to come along...)

sorry,

 

Your WCS/UCS should never change unless you change it. Perhaps try using the Viewcube to change to "Front view" instead of using "Front" from the Ribbon, Filemenu, or Toobar, as those not only rotate the view, they also re-orient the UCS.