Community
Civil 3D Forum
Welcome to Autodesk’s Civil 3D Forums. Share your knowledge, ask questions, and explore popular AutoCAD Civil 3D topics.
cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

extract only top lines from solids

8 REPLIES 8
Reply
Message 1 of 9
mkt
Enthusiast
800 Views, 8 Replies

extract only top lines from solids

I have approximately a 1000 solids (more or less cubes) from which I need the top lines. Any ideas for a not too manual workflow?

8 REPLIES 8
Message 2 of 9
mkt
Enthusiast
in reply to: mkt

Anyone?

Message 3 of 9
MikeEvansUK
in reply to: mkt

I had hoped someone else would pipe up with a better solution but.

 

Explode all objects to faces.

 

Flip to a side / front view and select all faces to be retained.

 

cancel selection

 

Invoke Erase then All Remove P

 

This should keep all the faces you want.

 

Mike Evans

Civil3D 2022 English
Windows 7 Professional 64-bit
Intel(R) Core(TM) i7-3820 CPU @ 3.60GHz (8 CPUs), ~4.0GHz With 32768MB RAM, AMD FirePro V4900, Dedicated Memory: 984 MB, Shared Memory: 814 MB

Message 4 of 9
mkt
Enthusiast
in reply to: MikeEvansUK

Thanks for the suggestion. I was not aware of that functionality in Erase. 

 

However, I was trying to avoid to manually select all the surfaces I want to retain. It is easier in a side/front view, but in my case, the solids represent buildings, and they all have different heights, which makes i quite a laborious task in e.g. cities. 

 

It might be the only way, but if anyone else has a automatic solution it would be much appreciated!

Message 5 of 9
antoniovinci
in reply to: mkt

mkt wrote:

if anyone else has a automatic solution


Nice question, sir.

Please _WBLOCK those solids as DXF_2004 file, then upload here in ZIP format: maybe I've an idea about it.

Message 6 of 9
mkt
Enthusiast
in reply to: antoniovinci

I really appreciate all the help!

 

I have attached a block of some of the houses. 

Message 7 of 9
antoniovinci
in reply to: mkt

Nope, I'm sorry. 

The idea was the following one:

  1. explode all up to line level
  2. _MAPEXPORT to a linear shapefile, with Elevation OD attribute
  3. thru an external tool, filter only the lines having Elevation >0, save as new shapefile
  4. _MAPIMPORT the latter
  5. _MAPCLEAN to create closed polylines out of those roofs

Unfortunately the point #3 doesn't work, just because your original solids don't lie on Z=0...

If you'll find a solution, please share it with us, thx.

Message 8 of 9
jmayo-EE
in reply to: mkt

Did the solids originate from an aerial survey data set?

 

If so how long did it take to make the solids and how long to get the job done?

 

It may be faster to build a single surface for all of those buildings if you need results as shown in the attachment. A surface is also nice if you want the buildings to display in profile or section views. The method I use will require going to each building and setting up breaklines but you go through the data individually only once.

Let me know if you want more info.

John Mayo

EESignature

Message 9 of 9
mkt
Enthusiast
in reply to: jmayo-EE

Attached you can see how my survey data looks. I want flat 2D polylines with the lowest z-value for each roof (not 0). The goal is to get the buildings into Infraworks with the possibility to choose facade, and roof material. 

 

The solids takes no time to make with a tool our developers have made. They could also make a tool to do what I want, but it takes time and costs money, so I wanted to investigate the possibilities properly before giving them the task. 

 

Thanks for the suggestion, but it doesn't sound like what I need. 

Can't find what you're looking for? Ask the community or share your knowledge.

Post to forums  

Rail Community


Autodesk Design & Make Report