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Dynamic block alignment in 3D

Printed From: CAD Forum
Category: EN
Forum Name: AutoCAD
Forum Description: Discussion about AutoCAD and AutoCAD LT, viewers, DWG and DWF formats, Design Review, AutoCAD 360, add-ons
URL: https://www.cadforum.cz/forum_en/forum_posts.asp?TID=5423
Printed Date: 16.May.2026 at 23:34


Topic: Dynamic block alignment in 3D
Posted By: AGVerheij
Subject: Dynamic block alignment in 3D
Date Posted: 08.Mar.2011 at 15:10
Hello,

I'm fairly new to the dynamic blocks after being away from AutoCAD for a few years. Working for a railroad-design company we create most drawings as 2D plans, but use a lot of 3D lines (poly or spline) especially for the centerline of the tracks. 

I have created some dynamic blocks that need to be placed aligned to the centerline of the track. It works OK if the centerline is 2D, but when I try to align it to a 3D line, the block is not rotating.

Is this a limitation of AutoCAD and/or the dynamic block definition, or am I missing something ?

With regards,
  Gerbert Verheij, NL


Replies:
Posted By: John Connor
Date Posted: 08.Mar.2011 at 15:36

All your dynamic blocks behave this way or just specific ones?

What makes a polyline 3D?


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"Humans have a strength that cannot be measured. This is John Connor. If you are reading this, you are the resistance."

<<AutoCAD 2015>>

Posted By: AGVerheij
Date Posted: 08.Mar.2011 at 15:47
All my blocks that use the alignnent grip behave in the same way: no problems on a 2D line, and no rotation when placing the block on a 3D line.

By 3D line I mean a 3DPOLY or SPLINE where not all the nodes have the same elevation, i.e. the line moves along the X, Y and Z-axis.

Gerbert

Posted By: John Connor
Date Posted: 08.Mar.2011 at 15:55

And the reason for doing a 2D drawing using 3dpolylines and splines is...?  I can't seem to wrap my mind around the concept.  Can you post a sample block you are using?  I'd like to attempt what you are trying to do.



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"Humans have a strength that cannot be measured. This is John Connor. If you are reading this, you are the resistance."

<<AutoCAD 2015>>

Posted By: AGVerheij
Date Posted: 09.Mar.2011 at 09:35
The data we use is delivered to us from survey teams or existing datasets. We design the tracks in 3D (for elevated crossings and bridges like in the drawing), but for plotting we make 2 drawings:
- a plan view with all surroundings
- a profile 'or side' view for the elevations
So a single data-set with different outputs. The blocks will be used by the people designing the overhead lines, and they use the elevations in the calculation of wire tension and stuff like that.
 
You can find the http://https://docs.google.com/leaf?id=0B-w95oRgu6XJY2JiOWVhNWMtOTQzZC00ZmFjLWFkOWItNzRiYjEwYWFiMzQ4&sort=name&layout=list&num=50" rel="nofollow - drawing here  (I hope the link works), it contains 6 centerlines for the railroadtracks that cross at different elevations and one of the blocks i'm trying to place. As you can see it works on the spline and not on the polylines.

Thanks for your interest !
 Gerbert

Posted By: John Connor
Date Posted: 09.Mar.2011 at 12:02
Tried your link but I.E. 8 had a problem with it.
Thanks for the explanation though.  Makes more sense now.


-------------
"Humans have a strength that cannot be measured. This is John Connor. If you are reading this, you are the resistance."

<<AutoCAD 2015>>


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