Dimension between two distinct viewports should show modelspace measure

[Anonymous]

Hello,

this is a small behavior I always wondered why AutoCAD doesn't work as expected:

We all know that (when in paperspace) if you create a linear dimension picking two points from a viewport, the measure shown is the real modelspace distance, as expected. Obviously, if you pick even a point in paperspace, the measure shown is taken from paper.

But often we use two viewports to detail two extremities of a long piece, like a bar for example, or even four to detail the four corners of a large panel.
This allow the designer to use a lower scale factor as often operation at the extremities are more valuable and/or complex.

But when you try to add a dimension picking the two points from two different viewports, for example to show overall width or height, the measure is taken from paperspace instead of the model.

Why?

It doesn't matter if the viewports are distinct, they show always the same modelspace, if I pick two points from modelspace I expect to get a dimensions that shows modelspace distance.

It doesn't even matter if the two viewports are not aligned or they are set to different scale factor, the two picked points are always at a specific distance in modelspace and that is the only measure that make sense.

For sure, the paperspace distance is meaningless, but it's the only one that AutoCAD use.

Hope someone will explain, and/or fix this small but (for us) important glitch.

Thank you!

Massimo

[ParishSouthBdx]

 need to dimension crosses multiple viewports.

As an example, I’ve got a simple bar here, 1'”x20”. I’m showing one end in each of two viewports to condense the display.

When I try to add dimensions, snapping to the corners of the bar, the short end works great but the long dimension displays the paper space distance instead of the actual length.

How to fix this? 

The suggestion is to replace the default dimension text with a field referencing the length of the object instead. Now, normally I don’t advocate overriding dimension text, but when you’re replacing it with intelligent text, I’ll make an exception.

Here’s how it works:

1. Double-click the dimension text to edit it, right-click, and select Insert Field.

2. In the Field dialog, set the Category to Objects and select Object under “Field names.”

3. Next to “Object type” in the dialog, click the “Select Object” button.

4. Here’s where it gets a little sneaky—and I can’t show it in a screenshot. You’ll just have to trust me (or better yet, try it yourself).

Click on the object you want to dimension, even though its viewport isn’t active. I know, it’s weird. But it works, just like it does when you’re selecting objects to dimension from paper space.

5. Back in the Field dialog, pick the property you want to reference (probably Length) and set the format and precision.

6. Click OK, and that’s it! You’re back in the drawing with an intelligent dimension that still knows what it’s attached to.

Admittedly this takes a little more effort than regular old associative dimensions, but once you’re used to placing fields, I think you’ll find it goes pretty quickly.

[Anonymous]

Drafting2,

thank you for your effort, it's a fair workaround, but to me it's not a solution. In my opinion AutoCAD is just showing the wrong numbers.

I'm involved also in AutoCAD education and when I try to convert draftsmen from 'detail everything in modelspace' (using dimscale and annotative functions) to paperspace detailing, this behaviour is often used as an excuse to keep detailing in modelspace because a so common feature is missing and require so much work.

To me, all annotative functions may be thrown away, maybe I am too 'old school'.

Massimo

[ParishSouthBdx]

I think we subscribe to the same camp.  What I hear you saying is that all graphics in model space, all text, dimensions, etc  paperspace....correct?

witht he advent of 3d models and intelligent sections cut from them and the trend that keeps pushing in that direction it fits that model also.

the model whether residing or as xrefs in model space used with paperspace viewports.  I still use 3dclip sometimes when the firm has plain jane autocad and thats it.  I hear more and more regarding sections and live sections and base views etc.....

 back to the original comment.....

What I hear you saying is that all graphics in model space, all text, dimensions, etc  paperspace....correct?

[Anonymous]

Sorry, not sure to have understood correctly...

What I said is that normally (both inside my company and with my customers) we keep the model in modelspace, regardless if 2D or 3D, and we detail in paperspace, using viewports as necessary. All dimensions or annotations are made in paperspace, using dimscale = 1.

Sometime, however, for many reasons or just for habit, some draftsmen keep putting dimensions on modelspace, putting them in different layers based on the dimscale used and on paperspace just set the right visibility for the right layer on the right viewport.
Of course he/she may use annotative scaling, but, nevertheless, they just apply dimensions in modelspace (with a lot of extra work, in my opinion) and play with visibilities in paperspace.

I'm not here to criticize, I know people that do all the drafting in modelspace. They learnt that way and they keep going. Fine for me. 

I just wish that a standard command like DIM, used in a standard way (like dimensioning in paperspace through viewports) would just show the only meanigful value possible. That's all, shouldn't be that difficult.

Otherwise I'd like to hear why, in that situation, the value shown should be the paperspace distance, 'cause I cannot imagine a real scenario.