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pete84

How do i make series of cross sections of simple landscape

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pete84

Hello,

I'm using Autocad 2014 as a landscape architect student, and I'm still a beginner.

 

I need to make a series of cross-sections to describe a terrain. I have contours of a 100 km stretch (only from 1 to 20 m) and need roughly 50 sections to describe the landscape. Is there a simple way to get the surface line for each section??

 

I would very much like to avoid making each by hand :(

 

I did a little research in here and it seems this thread is closest to mine:

 

http://www.cadtutor.net/forum/showthread.php?21255-cross-section

it has this "quickprofile.lsp" attached.

But i think it has to have the contours on the same layer - i cannot get to work for me.

 

Does anyone have a suggestion for me?

 

Thank you

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eldon

Are your contours at the elevation that they should be, i.e. in 3D, and not just annotated with the elevation?

 

Are your alignments drawn as polylines (not just lines)?

 

I have used the lisp that you have discovered, but all the lines have to be as the lisp expects them to be!

 

Perhaps, one way to help would be for you to post a drawing, so that your data could be inspected.

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pete84

Hi,thanks for taking the time.

 

I think my contours are in 3D (when I choose south view I see the polylines above each other) and the drawing is entirely in polylines. Though they are not all aligned, as the drawing will be to heavy.

 

The file is too big to attach :( ..

 

My problem with the lisp seems to be that i don't understand how to choose the layer name of the contour, i have about 25 layers i need included in the profile, will this mean i have to write each layer manually for the lisp to succeed?

 

My intetntion is to take the sections out of autocad and design them in another program, so I only need the outline for each section.

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eldon

It is such a long time since I used the lisp that I did not remember how it worked. But if it wants the layer name, have you thought that you could copy all the contours onto a single layer, just to get the programme working. You could always delete that layer afterwards.

 

And make sure that the alignment is a LWPolyline.

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ReMark

You could always upload the drawing to a file sharing website like DropBox and post a link to it here. Anyone interested in helping you could download and open the drawing to see what you are describing.

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BIGAL

Click on a contour and have Properties open it should describe what it is PLINE with a Z not zero and layer name. Maybe like cont2 cont3 for layer names, see comments above.

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pete84

Hi everyone,

 

Thanks for the inputs.

All contours are polylines and have z value.

 

Here is a link to the drawing:

https://www.dropbox.com/sh/nvbabiwwsrh37sc/AAArG73JyVlkACHMcVQkmZEga?dl=0

 

When I run lisp i get this error:

"; error: vl-load-com not supported on "Mac OS X Version 10.8 (x86_64)"

 

Which makes me think it might be a compatible problem with my mac :( plus the thread with the lisp is from 2008, so maybe it is outdated (if that is even possible?)

 

Suggestions would be very much appreciated :) other tools or even another software program if anyone have a suggestion!

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ReMark

So you are running AutoCAD on a Mac and not on a PC. Your profile should read AutoCAD for Mac 2014.

 

Visual lisp is not supported on the Mac. Now if the routine were written in plain AutoLisp then I think it would function as expected.

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Cad64

Suggestions would be very much appreciated :) other tools or even another software program if anyone have a suggestion!

 

Why don't you just do them manually? In the time it's taken to get to this point, you could have done them all and been finished with it.

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ReMark

It looks like you currently have 14 section lines (layer "sections", color: yellow) approximately 2000 units (meters?) apart and you are going to subdivide each into four additional sections at 500 units (meters?) apart for a total of 52 cross-sections?

 

The layers that start with the letters "cont" are the contour layers right? So do the numbers after the letters refer to the height of the contour in meters? For example does the layer cont18 represent a contour that is 18 meters?

 

Well in any event I can see why you would be looking for a custom lisp routine.

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pete84

You're right "cont18" is 18 meters.

 

And actually the drawing attached here is just a section of the drawing, the original is about 80mb and have 70section lines 2 km apart.

 

In response to why I don't just do it by hand. I now it may be faster by this point, but i'm a student and figured i'll like to learn :) - and there must be other people who have wanted to do this before me... maybe it will be by hand in the end. For now my semester is long, and I still have time to try to figure it out.

 

 

And sorry about the Mac omission, I didn't know I could differentiate. i think i fixed it.

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ReMark

You'll have to see if you can find a more Mac friendly lisp routine if that is the route you want to go.

 

What program was used to generate the contour map?

 

The "Using:" item under your user name is what you should have updated in your Profile.

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pete84

I'll look around, or maybe see if i could borrow a pc.

 

I'm not sure, i think it was from MapInfo, I got the drawing through school as a dwg file though.

 

I looked under "using", but there is no option specifying mac (only AutoCAD LT, Architecture etc.)

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ReMark

That's odd. No Mac-n-Cheese setting? LoL

 

I think the powers-that-be ought to correct that oversight. You are not the first to post a question that uses AutoCAD for Mac.

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Cad64

Just my opinion, but since you're a student, I think it would be best if you do these cross sections manually so that you learn how to do them correctly. Using a lisp routine to create them automatically doesn't really teach you anything. Lisp routines are great for a work environment, to help speed up productivity, but for a student, I don't think you should be relying on them. You might end up working in an office where IT controls what can or can't be loaded on your machine, or maybe they use Autocad LT, so you wouldn't be able to use custom lisp routines. Understanding how to create accurate cross sections is important for your proposed line of work. I've been working as a landscape architect for over a decade and I do cross sections on a pretty regular basis. I've never had to do 50 at one time, but I could do them pretty quickly if I had to.

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BIGAL

A manual way draw a line over your contours where each line hits the contour create a perpendicular line from this point, draw a circle of radius = contour value say 18 make sure it crosses the perp lines, joint all the intersecting circle and line crossings that is your cross section.

 

Yes a lisp way is to use ssget and a fence selection option then either a inters or Intersectwith to find intersecting point and then add the rl then draw a pline.

 

Screen Shot 01-20-16 at 01.07 PM.jpg

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eldon

I have drawn sections manually, but I prefer to draw them in plan with a 3D polyline and use the Apparent Intersection Osnap. When it is drawn, then I rotate 3D, and there is the cross-section.

 

When using the Apparent Intersection pick each line individually and the z value seems to be taken from the first line picked. So pick the contour first and then the cross section alignment line second. But as always, sometimes it may not pick up the z value, so check the coordinate display.

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ReMark

While looking at your drawing this morning I notice the units are in imperial inches yet you seem to indicate you'll be working in metric units. Am I missing something here? I also see now that each contour has a "Z" elevation. Maybe there is a tool here... http://www.glamsen.se/CadTools.htm that you could use to generate each section. The yellow section lines have an elevation of "1".

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