Expert: Bill DeShawn - 6/13/2008

Question
QUESTION: Aloha, here I am to bother you again!
I have AutoCAD 2008 and I'm trying to dimension my drawings in paper space (layout) rather than model space (because that is the way 'they' say it should be done. When I try it however, the dimensions won't 'stay put.'   For example after dimensioning, if I ZOOM or PAN the layout in model space, the dimensions get all screwed up and no longer point to the correct places. I've made sure they start at end points and not nodes thinking this might be the problem.   

Am I doing something wrong or is this a bug? :-(   Once again, thanks for your time!!!

Actually I don't really see the benefit of it except for scaling. If I add something in model space after dimensioning in paper space, I might have to move the dimension because it overlaps.

Jim

ANSWER: Jim.  When you zoom and pan in model space while in a layout, your viewport needs to be locked.  First, set the scale the way you want it with Zoom and then the XP option.  Then go to PSPACE and right click on the Viewport, find DISPLAY LOCKED and select YES.  Now you can dimension your paper space objects, then go into model space, pan and zoom, and your view in the viewport will not change and your dims will be valid.  After you've started dimensioning, if you have to adjust the view in the viewport, it's better to stretch the viewport with its grips than to go into Model Space and change the pan or zoom.  Dimensioning in paper space has its advantages sometimes, but it also has its disadvantages.  If DIMASSOC is set to 2, then your dimension will remain associative to objects dimensioned.  If you dimension to an object snap or object, it will be associative to geometry in model space.  But if you draw on snap and dimension on snap (not object snap), your dimensions will not be associative to model space geometry.  

If you aren't grasping the concept, keep the dialog going, and we'll talk further
Keep in touch
Bill DeShawn
http://my.sterling.net/~bdeshawn


---------- FOLLOW-UP ----------

QUESTION: Thanks for your time once again Bill. I must have something set that is messing things up.
I right-clicked on the viewport and found it was locked. I checked DIMASSOC and it is set to 2.
I then dimensioned an object I had drawn in model space (using snap.) Then I intentionally went into model space and zoomed. Returning to paper space, the dimension did not change to the new zoom. :-(
I think I like dimensioning in model space anyway. Sometimes I have a bit of a problem with scaling properly in paper space (so the text isn't too big or small), but not often.
I have more of a problem trying to get dotted or dashed lines to plot out as they look in model space. That drives me crazy sometimes!
Aloha,
Jim :-)

ANSWER: I don't think your viewport display is locked.  Before you lock the viewport, and while in the model space viewport, and with the entire viewport frame visible, run the zoom command and then type 1XP.  then Pan to a good spot. Then immediately type _.PSPACE and click on the viewport to highlight it and get the grips showing.  Then right-click on the same viewport and scroll down to "Display Locked" and and select "Yes".  Then, using grips, stretch your viewport to fit
the model.  Now dimension the model space geometry from paper space.  Don't use SNAP.  Use Object Snaps.  List the viewport.  There should be a line there that says:
Scale relative to Paper space:    1.0000xp
That means that paper space scaling and model space scaling is the same.  When you did a Zoom 1XP, the two scales were made equal at 1:1.  Now, when you zoom inside the viewport, although it looks bigger on screen, it's not bigger on your paper and it the same size relative to your viewport because the viewport it locked.  The scale is now cast in stone until you unlock the viewport and change the scale factor by zooming.  You can edit in model space viewport or shift over to the model tab to edit.  Because your paper space scale is now equal to model space scale, your linetype scale should be perfect.  If you need to plot something in model space that is outside the limits of the paper size, you will need to scale the plot down.  Do that as opposed to changing the zoom factor of the model space viewport.  This will prevent linetype scale problems.
There is another way, but I'm not going to talk about that right now.  I want you to learn this way first.  This way came way before the next way, and is still easier.

Keep in touch
Bill DeShawn
http://my.sterling.net/~bdeshawn



---------- FOLLOW-UP ----------

QUESTION: This is a copy of the email I sent to your website with the drawing attached. I hope that was OK...
***************************************
Hi Bill

Boy! Thanks for taking so much time!! I'm feeling guilty about taking so much of it...now it is starting to drive me crazy! I am therefore taking the liberty of sending the drawing I was trying to dimension in pspace to you.

I made a special layout called 'Test dimension' and tried to follow your instructions to the letter. First I unlocked the viewport (or at least think I did) then I commenced.

When I did the ZS1xp command in model space from paper space there was nothing small enough to see upon returning to paper space, so I made a 3X3 box to show in the viewport.

I then locked the viewport (again at least I think I did) and dimensioned it in pspace.

When I zoom and pan in model space, I have to re-scale (ZS [any scale]) while still in model space to get the dimensions to return to the box. I.e., if I zoom and then return to pspace without re-scaling to ANY scale, the dimensions aren't on the box.

I used (and use) OSNAP to snap to objects. When I list the viewport after all of this, the scale is still .0208xp.

Maybe there is some GENERAL setting I'm missing??

I'm sorry I'm so thick...thanks again for your time!!

Jim  

Here is the list of the viewport:

Command: list

Select objects: 1 found

Select objects:
         VIEWPORT  Layer: "0"
         Space: Paper space
         Layout: Test dimension
         Visual Style: 2D Wireframe
         Handle = b57db
         Status: Off
         Scale relative to Paper space:    0.0208xp
         Annotation Scale: 1:1
         View lock is on
         center point, X=0'-11 1/8"  Y=0'-7 3/4"  Z=    0'-0"
         width 1'-9 7/8"
         height 1'-3 1/16"


Answer
OK.  First off, you didn't do a zoom 1xp.  If you did, it wouldn't have reported thus:
Scale relative to Paper space:    0.0208xp
You did a zoom 1/48xp.  That's OK, but if you do that, be sure to set PSLTSCALE to 1 so you can see your linetypes correctly.  (you might have to regen to see the results after changing the value of that system variable).

My preference is to draw a big viewport and ZOOM to 1xp.  Then I plot to 1/4" = 1'-0".  Then it doesn't matter how I have PSLTSCALE set.  It will look perfect every time.  Your title blocks will have to be 48 times bigger to do that.  Dimensions will need a DIMSCALE set 48 times their current setting.  My guess is you have it set to 1.00 right now.

But your issue is viewports panning and zooming and changing their xcale factor.  That can only happen if the display of the viewport is not locked, because when it is locked, AutoCAD temporarily puts you back into paper space to zoom or pan and when you're done, it puts you back into model space.  Watch the Model/Paper button at the bottom of the screen to see that happen.  Test the locking this way before you add dimensions in paper space.  If the viewport is locked, and you pan and zoom in the viewport, the relative position of model space geometry and paper space objects DOESN'T CHANGE.  

If you change geometry after you put a dimension in paper space, the dimension will change, too, IF you dimensioned to an object or an object snap.  

Set DIMASSOC to 2

Dimensioning to an object:  When doing a linear (vertical, horizontal or aligned) dimension, and when you see the following prompt:
Specify first extension line origin or <select object>:
Hit enter and pick an object.  You don't always have that luxury, but sometimes you do and it speeds things up when you take advantage of the opportunity.  

Dimensioning to an object snap:  When doing a linear dimension hold your SHIFT key down and press your right mouse button and pick an ENDPoint or other object snap.  If the object gets edited but not replaced or deleted, the dimension is associative to the geometry.

If you want the dimension to be associative to the geometry you can't dimension to some place out in space that lines up with the geometry.  That doesn't cut it.  You actually have to pick objects or object snaps.

Don't confuse Object Snap with SNAP.  SNAP is relative to the SNAPBASE system variable and will not help your dimensions' associativity.  

I don't think your "thick", but sometimes I think you're getting it, and because you say:
"if I ZOOM or PAN the layout in model space, the dimensions get all screwed up and no longer point to the correct places." this leads me to believe that your viewport is NOT LOCKED!  Because if it is this is not supposed to happen. But then again, your list says:
View lock is on.
Sending me the drawing might be a good idea., but since this is not a private session, I need to you go to my website and click on the email icon at the bottom of the page and send me the drawing so I can have a look at it on my ACAD 2008.  Plus I can also send you back an additional layout with the parameters that I would have used for scale.

Keep it going
Bill DeShawn
http://my.sterling.net/~bdeshawn