Author Topic: 3D solid dimesioning in M-space  (Read 6007 times)

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jura

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3D solid dimesioning in M-space
« on: March 14, 2007, 10:14:26 AM »
Hi all,

I've got this small but annoying thing when dimensioning 3D solids in modelspace.

In some cases the dimension line disappairs behind the object (my preference) and some times i doesn't. Is there a setting that controls this.

Even within one drawing 2 different dimensions. Both use same dimstyle and layer. Both are linear dims. I cant find any difference between them.

Any help is very much appriciated

Grz, Jura


t-bear

  • Guest
Re: 3D solid dimesioning in M-space
« Reply #1 on: March 14, 2007, 03:51:47 PM »
I have the same thing, especially with cylinders.  I want the dimlines to show so I move the ucs to the front of the model. Now the dimension will be in front while the anchor point (defpoint) will be on the proper location.   Seems top work for me.........

CADaver

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Re: 3D solid dimesioning in M-space
« Reply #2 on: March 15, 2007, 11:39:27 AM »
ummm... never mind...

t-bear

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Re: 3D solid dimesioning in M-space
« Reply #3 on: March 16, 2007, 02:06:26 PM »
ummm... never mind...
Yep.....dimension in PS......right?   :lmao: :angel:

CADaver

  • Guest
Re: 3D solid dimesioning in M-space
« Reply #4 on: March 16, 2007, 08:23:25 PM »
:)

t-bear

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Re: 3D solid dimesioning in M-space
« Reply #5 on: March 19, 2007, 09:58:24 AM »
I do a lot of dimentioning in PS....problem comes with cut sheets.  I have a 36' steel w-beam with holes and notches....need to dim this piece.  So....I create 3-4 vports to "section" the object.  Unfortunatly, ACAD will not dimension the piece accuratly in PS....I have to do it in MS in  this instance.

jura

  • Guest
Re: 3D solid dimesioning in M-space
« Reply #6 on: March 26, 2007, 12:22:48 PM »
Sorry not to reply sooner guys, the wife made me go on vacation. Ofcourse i preffered to stay here and wait for your replies but really couldn't. ;-)

Any way that's the off topic part, to get to this;

Let me clear the modelspace issue first. Reason for dimensioning in modelspace is that we're working a lot with isometric views (eg. SE, SW, NE or NW view) Dimensioning this in paperspace would be a hell, cause dims will not get the right dimension. Manually changing the dimtext?? I don't think so.

I'll try to explain my problem more thoroughly. I'm aware that i can move the anchor point of the dim. But i want them to disappair behind the 3D objects (solids and wblocks of solids) I theory they should disappair cause they are physical (yet still virtual ;-) ) behind the object. Somehow they disappair not in all cases. So same drawing, same dimstyle, same 3D objects different appairance.

See attached screenshot. (dimline 225 mm is ok, dim 1499 is not hidding)

Any tips????





Josh Nieman

  • Guest
Re: 3D solid dimesioning in M-space
« Reply #7 on: March 26, 2007, 12:32:06 PM »
Dimensions will always be squarely on the XY plane, no matter what you snap to.  Wherever your origin is, the dimension will be there.  Is your dimension actually tied to that physical corner or point you are dimensioning, or is it 31384 units above it? 

deegeecees

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Re: 3D solid dimesioning in M-space
« Reply #8 on: March 26, 2007, 01:11:20 PM »
If I may assume for a minute that your plan view is perp to world UCS, then set your ucs to <world>, then set your ucs "Origin" to the center of that object you are dimming from, then redimension it, at present it looks as if your ucs is set to somewhere above the object.

Clear as mud?

DaveW

  • Guest
Re: 3D solid dimesioning in M-space
« Reply #9 on: April 02, 2007, 11:39:33 AM »
jura,

I have a solution for you, but you have to dim in paperspace. Please follow this through to the end. I realize some of this you know, but I am trying to spell it out clearly for newer people too.

Now you MUST have associative dimensions turned off in tools, options, user preferences tab.

Let me give you an example. Let's say you have two different dimension styles for dimming in paperspace.
One for full size and one for 1 1/2" = 1'. You have to edit the scale factor box on the primary units tab in the dimension style editor. For the full size dim style you put a 1 in the box, as you are dimensioning 1 to 1.
For the 1 1/2" = 1' style, you will have to call it something different as acad does not allow the "/" character, you put the number 8 in. Why? Because that is for dimming a viewport who's scale has been reduced 8 times.

You see 1 1/2" = 1' is really 1 1/2" = 12". We want apples to apples or oranges to oranges. ie, inches to inches and NOT inches to feet.
So, if we divide 12" by 1 1/2" then we get 8. 1 1/2 is 8 times smaller then 12. For the scale factor of the viewport we put 1/8xp. Open the viewport and type z, enter, 1/8xp, enter. Now the viewport is 8 times smaller and is a at a factor of 1 1/2" = 12".

So when we go to dimension our viewport we use our dimension style for 1 1/2" = 1', where we have an 8 in the scale factor box. Now whatever acad returns as a measurement will be multiplied by 8 and we have the real world value displayed in the dim line instead of a value that is 8 times too small.

Make a 3D solid in modelspace that is 10 x 5 x 1.

Go to paperspace and make 2 viewports

First we will start with 2 typical orthographical views. Open each viewport and set the view to top or world.

Set one viewport to full size, z, enter, 1xp, enter.
Set the other to 1 1/2" = 1'. z, enter, 1/8xp, enter.

Use the 2 dim styles to dim them. You should have the values 10 and 5 on both views.


If you got this far, now for the fun part.

Dimming non-orthographical views in paperspace.

Create 2 more viewports and set the views to se isometric. (An acad isometric view is not a true isometric as there is no vanishing point. It is really an axonometric view). Also keep in mind that this will not work for perspective views.

Set each viewports scale. One at full size and one at 1 1/2" = 1'.
Open your dimension style editor and set it to decimal and to the highest precision possible.
Now dim the full size view on the 5" side with an angular dimension.
It will return 4.08248283.

Now for some simple math.

4.08248283 x n = 5

We divide 5 by 4.08248283  and that leaves us n.

5 / 4.08248283 = 1.22474487278318
Create a new full size dimstyle for this angle of view and edit the dim style scale factor box and put in 1.22474487278318 and set it as the current dimstyle.

Now when we dimension the full size view the 5" side says 5" and the 10" side says 10" on the dim line.

For the 1 1/2" = 1" dim style, copy it, edit the scale factor box and multiply 1.22474487278318 x 8, which is 9.79795898226544.
This will give us the correct dims for the se axonometric view that is scaled to 1 1/2" = 1'.

If you are using standard isometric/axonometric views, you need only create a few more dim styles in your template and use them again and again. You can always twist your view and create new dim styles on the fly, but keep in mind that if the view is not a typical iso, only 1 direction will work at a time for each new dim style.

Now you have nothing, but your 3D solids in modelspace. IMO this is the ideal way to work.




JDMather

  • Guest
Re: 3D solid dimesioning in M-space
« Reply #10 on: April 02, 2007, 09:59:04 PM »
Autodesk Inventor 2008 will have isometric dimensioning and will read/write dwg.
« Last Edit: April 02, 2007, 10:01:47 PM by JDMather »

DaveW

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Re: 3D solid dimesioning in M-space
« Reply #11 on: April 04, 2007, 10:28:12 AM »
Autodesk Inventor 2008 will have isometric dimensioning and will read/write dwg.


That is pretty interesting. I am sure this is a utility that can be used everywhere. After looking at the issue and typing up the post above it seems like it may be pretty easy to add it to ACAD with some simple VB coding right now. Either as a dimension modifier, where you click on the dimension and the code gets the viewport below the nodes, then gets the viewports scale, then factors in the view degrees, and then fixes the dims. Again, it is easy to do where the angles are even left, right, and top, but the twisted views would be difficult as far as I can tell, but not impossible. You could do it in C++, and maybe in VB.NET (I think I saw I could parse through the innards of a 3D solid in VB.NET), if you were working with 3D solids and could get the actual lines, arc, circles, and splines inside the 3D solids at the nodes, measure them with code and just fix the dim line.

Bottom line is that it may only take 1 minute for a user to copy all their existing dim styles and edit the new ones with the axonometric value, then add them to their template dwg. ACAD may not have the feature built in with one click, but an experienced user would not not even pause at this issue, as ACAD can do it if you know how to use it.