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How to an alignment and profile from a 3d spline?

13 REPLIES 13
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Message 1 of 14
Cadguru42
5244 Views, 13 Replies

How to an alignment and profile from a 3d spline?

I'm wanting to make a corridor model from an imported DGN that contains centerlines and edges of pavement for a neighborhood.  From 2011 and 2012, the import creates splines while 2010 and older create 3d polylines.  

 

The alignment creation from objects does not work on a 3d polyline or spline and I have no clue how to make a profile from the same object.  How could I go about making an alignment and profile from a 3d spline or 3d polyline?  Seems like that should be something simple, yet I'm stumped.

 


C3D 2022-2024
Windows 10 Pro
32GB RAM
13 REPLIES 13
Message 2 of 14
tcorey
in reply to: Cadguru42

Here's a quick way to solve your issue, at least with 3D polylines. I have not tested with splines, but I think it will not work:

 

http://screencast.com/t/fatZxtxldO

 

Best regards,

 

Tim

 



Tim Corey
MicroCAD Training and Consulting, Inc.
Redding, CA
Autodesk Gold Reseller

New knowledge is the most valuable commodity on earth. -- Kurt Vonnegut
Message 3 of 14
Cadguru42
in reply to: tcorey

I would love to watch that video but our idiotic IT masters block screencast so I have no way to view it.

 

C3D 2022-2024
Windows 10 Pro
32GB RAM
Message 4 of 14
tcorey
in reply to: Cadguru42

Sorry, that's the only place I saved it, so I can't email it to you. Maybe you can get the IT Nazis to give you special permission for three minutes and thirty-six seconds. I will give them my personal guarantee that it's not porn.

 

Tim

 



Tim Corey
MicroCAD Training and Consulting, Inc.
Redding, CA
Autodesk Gold Reseller

New knowledge is the most valuable commodity on earth. -- Kurt Vonnegut
Message 5 of 14
907Trekker
in reply to: Cadguru42

I can't get this to work for a spline, but for a 3d polyline an easy way to make an alignment and profile is to make a "Quick Profile" from the profile dropdown, make sure you select the "draw 3d entity profile" box.  Then under the file menu select Export -> Export to LandXML.  The press the uncheck everything button.  Then use the select button to just select your profile.  This will export an alignment and a profile to an xml file.   Just reimport it and you are good to go.

 

So in summary, quick profile, export it to land xml, reimport it.  I attached a few pics.

 

 

Message 6 of 14
tcorey
in reply to: Cadguru42

Nice, straight-forward solution.



Tim Corey
MicroCAD Training and Consulting, Inc.
Redding, CA
Autodesk Gold Reseller

New knowledge is the most valuable commodity on earth. -- Kurt Vonnegut
Message 7 of 14
Cadguru42
in reply to: Cadguru42

Thanks for the information!  I did end up getting to watch the video by using my boss' Galaxy Tab 10.1.  I am going to try the other method mentioned about the quick profile and LandXML method. 

 

Seems like there should be a much easier way to use a 3d spline/polyline to accomplish the same task.  In fact, I think having a 3d polyline or spline would be much better and easier to use as a baseline in a corridor than the two separate entities of alignments and profiles.  I know that's how road design has been done for eons, but internally it would be so much easier to program and just do a type of sweep/loft along a path similar to how 3ds Max could do a road.

 

Oh well, back to work.  Thanks again.

C3D 2022-2024
Windows 10 Pro
32GB RAM
Message 8 of 14
907Trekker
in reply to: Cadguru42

I agree, and it seems like C3d is so close to being able to do this.  You can make an alignment and profile from a corridor feature line so why not from a regular feature line?  You should be able to just convert your 3d polys (or maybe splines) to a feature line and press a button. 

 

I know it would make my life easier...

 

 

Message 9 of 14
ralstogj
in reply to: 907Trekker

Found this tip on using the flatten command to get a polyline with arc's from a spline no z  throu.

http://lynn.blogs.com/lynn_allens_blog/2011/07/an-autocad-hip-tip-on-turning-splines-into-plines.htm...

 

 

Regards

Justin Ralston
http://c3dxtreme.blogspot.com/
Message 10 of 14
Sinc
in reply to: Cadguru42


@engrtech wrote:

Seems like there should be a much easier way to use a 3d spline/polyline to accomplish the same task.  In fact, I think having a 3d polyline or spline would be much better and easier to use as a baseline in a corridor than the two separate entities of alignments and profiles.  I know that's how road design has been done for eons, but internally it would be so much easier to program and just do a type of sweep/loft along a path similar to how 3ds Max could do a road.



The problem with that is we typically Engineer things in the Civil world.  And for that, it is by far easier to use the 2-1/2D paradigm (e.g. horizontal layout + elevation) vs. a true 3D paradigm.  Artists and machinests find it easier to use the true 3D, but when it comes to a construction project, true 3D can greatly increase the complexity while not really helping.

 

Same thing with splines, even in 2D.  They're a lot more complex a geometric figure, and make land work much more difficult.  There's the raliway and highway curves, but those tend to be described in a rather simplified form that limits options, and makes it possible for computers (including calculators, data collectors, smart phones, etc.) to do those calcs with a minimum of input.  Using free-form 3D splines makes for a lot more complicated possibilities, creating difficulty for everyone who must then build your design.

Sinc
Message 11 of 14
Cadguru42
in reply to: Sinc


@Sinc wrote:

@engrtech wrote:

Seems like there should be a much easier way to use a 3d spline/polyline to accomplish the same task.  In fact, I think having a 3d polyline or spline would be much better and easier to use as a baseline in a corridor than the two separate entities of alignments and profiles.  I know that's how road design has been done for eons, but internally it would be so much easier to program and just do a type of sweep/loft along a path similar to how 3ds Max could do a road.



The problem with that is we typically Engineer things in the Civil world.  And for that, it is by far easier to use the 2-1/2D paradigm (e.g. horizontal layout + elevation) vs. a true 3D paradigm.  Artists and machinests find it easier to use the true 3D, but when it comes to a construction project, true 3D can greatly increase the complexity while not really helping.

 

Same thing with splines, even in 2D.  They're a lot more complex a geometric figure, and make land work much more difficult.  There's the raliway and highway curves, but those tend to be described in a rather simplified form that limits options, and makes it possible for computers (including calculators, data collectors, smart phones, etc.) to do those calcs with a minimum of input.  Using free-form 3D splines makes for a lot more complicated possibilities, creating difficulty for everyone who must then build your design.


 

I think you misunderstood what I meant.  I meant having the coding and such inside Civil 3D use splines or 3d polylines, but we still input the design as civil engineers have done for ages using the 2.5D paradigm.  Seems like it'd just make it easier for corridor modeling if it's a spline/3dpolyline as a baseline and you sweep/loft the cross section on it.  From there, extract the information you need for EOP (ETW), BOC, daylights, etc.  

C3D 2022-2024
Windows 10 Pro
32GB RAM
Message 12 of 14
Sinc
in reply to: Cadguru42

3D Polylines cannot have curves.  And 3D splines are a more-complex geometrical figure, that cannot be labeled the way we wish in a 2.5D paradigm.

 

So why use 3D splines if you're already in a 2.5D paradigm?  I don't see it as being "easier".  In fact, I see it really complicating issues.

Sinc
Message 13 of 14
wfberry
in reply to: Sinc

"ARCH A teks" use splines, Engineers do not.

 

Smiley Wink

 

Bill

Message 14 of 14
wfberry
in reply to: wfberry

 

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