Creating a topographic map from Survey Data

Hello All,

 

Thank you for welcoming me into your community. I am in quite a pickle. I have to create a 3D topographic map from survey data, using polylines and interpolation. The contour interval is 2'. The survey data is already in a dwg file (elevation and postion). I am using AutoCAD 2010. My knowledge in AutoCAD is really small and I really don't know how to start. Later in the project I have to cut a road in the topograph and measure the amount of soil I have removed. It is due this evening and I don't know what to do. Please help. Thank you in advance for your response

 

You really should be using a civil program not plain AutoCAD to do this. Isn't it a bit late in the game to be popping in with this question? Due tonight? Yikes!

 

Try a Search of the forums using the words create topo map and see what it brings up. You definitely have your work cut out for you.

That's the feeling I get, but I have to used AutoCAD

That's the feeling I get, but I have to used AutoCAD

 

AutoCAD does not have a built-in capability to interpolate contours from spot elevations. You would need some sort of add-on program or you would have to extract all the elevations (with their northing and easting coordinates) to a file that could be used by a topographic program to do it. Then you would have to get the contours out of the program and back into AutoCAD and use them to create a solid. At least that's the way I see it.

 

Hpw many spot elevations are you working with?

Here is what I am working with

Is it possible also get additional interpolated points, connect those points with 3D polylines and create a surface from there. I have an short application for interpolation. I am running it, but I don't know where the data is ending up.

I'm blind so posting another copy of the image isn't going to help. Thanks anyways.

 

Here, don't say I never tried to help you. A link via a previous thread re: free contouring program. I cannot vouch for it but it is worth a try.

 

http://www.cadtutor.net/forum/showthread.php?21290-free-Contouring-program

Is it possible also get additional interpolated points, connect those points with 3D polylines and create a surface from there. I have an short application for interpolation. I am running it, but I don't know where the data is ending up.

 

What application? Do you know what the file type is for the data?

Here is the application code

 

;; This program was written to interpolate even contour intervals

;; from data provided by a survey.

;;

;;

;; Written for Civil Engineering Graphics 170 class project.

;; Kent Hobson

;; Department of Mechanical Engineering

;; University of Wisconsin - Madison

;; October, 14 1992 - 2001

;;

;; Standard disclaimers apply: I am not responsible for anything that goes

;; wrong with this program. If you can not make

;; this autolisp program work, then do it by hand.

;;

;;

(defun datumchk ()

;;calc delta elevation 1*********

;;which datum is larger

(if (> p1ee p2ee)

(progn

(setq diff1 (- p1ee p2ee))

(setq newc (fix p1ee))

(setq refel p1ee)

(setq lowel p2ee)

(calccnt p1eb p2eb refel lowel)

)

(progn

(setq diff1 (- p2ee p1ee))

(setq newc (fix p2ee))

(setq refel p2ee)

(setq lowel p1ee)

(calccnt p2eb p1eb refel lowel)

)

)

 

;;calc delta elevation 2***********

;;which datum is larger

(if (> p1ee p3ee)

(progn

(setq diff1 (- p1ee p3ee))

(setq newc (fix p1ee))

(setq refel p1ee)

(setq lowel p3ee)

(calccnt p1eb p3eb refel lowel)

)

(progn

(setq diff1 (- p3ee p1ee))

(setq newc (fix p3ee))

(setq refel p3ee)

(setq lowel p1ee)

(calccnt p3eb p1eb refel lowel)

)

)

;;calc delta elevation 3*********

;;which datum is larger

(if (> p2ee p3ee)

(progn

(setq diff1 (- p2ee p3ee))

(setq newc (fix p2ee))

(setq refel p2ee)

(setq lowel p3ee)

(calccnt p2eb p3eb refel lowel)

)

(progn

(setq diff1 (- p3ee p2ee))

(setq newc (fix p3ee))

(setq refel p3ee)

(setq lowel p2ee)

(calccnt p3eb p2eb refel lowel)

)

)

;;select the next set

(setq ans (getstring (strcat "\nDo another set?

"y" ">\\n ")))

(cond ((= ans "y") (gdata))

((= ans "Y") (gdata))

((= ans "") (gdata))

((= ans "n") (princ))

((= ans "N") (princ))

(t nil)

)

)

;_____________________________________________________________

;;find the first contour to print

(defun calccnt (a b hel lel)

(if (/= (rem newc ci) 0.0)

(progn

(setq rem_v (rem newc ci))

(setq newc (fix (- newc rem_v)))

)

)

(while (>= newc lel)

(progn

(drawpt a b hel lel newc)

; (princ "\nnewc - ci ")

; (princ "newc ")

; (princ newc )

(setq newc (fix (- newc ci)))

)

)

)

;_____________________________________________________________________

(defun drawpt (a b hel lel newc)

;;calc the distance between data points

(setq d (distance a b))

;(princ "distance = ")

;(princ d)

;;calc the angle between data points

(setq pangle (angle a b))

;(princ "newc = ")

;(princ newc)

 

;;calc a real elevation difference to be plotted

(setq zvalue newc)

(setq zpt (rtos zvalue 2 4))

;(princ "\nzvalue = ")

;(princ zvalue)

 

;;interpolate the location of the new contour point

(setq diff2 (- hel newc))

(if (/= diff1 0.0000)

(setq deltax (/ (* diff2 d) diff1))

(setq deltax 0.0001)

)

;(princ "deltax = ")

;(princ deltax)

 

;;plot a new point and write elevation text

(setq startpt (polar a pangle deltax))

(setq xpt (rtos (car startpt) 2 4))

(setq ypt (rtos (cadr startpt)2 4))

;(princ "\n\n\nthis point is for plot")

(command "point"

".xy"

(setq plotpt startpt)

(setq 3pt (* 12 zvalue))

)

;(princ "\n3pt = ")

;(princ 3pt)

(command "text"

".xy"

(setq txtpt (polar plotpt 0.0 (+ r 0.2)))

(setq mpt 3pt)

""

"0.0"

(setq prntxt newc)

)

)

 

;get contour interval

(defun getci ()

(setq ci (getstring "\nEnter the Contour Interval: "))

(setq ci (atof ci))

(setvar "pdmode" 35)

(setvar "cmdecho" 0)

(command "layer"

"n"

"1_tmp_data"

"c"

"6"

"1_tmp_data"

"s"

"1_tmp_data"

"off"

"1_tmp_data"

"y"

""

)

)

 

 

;enter datum information for first point from contour map

(defun gdata ()

(graphscr)

(initget (+ 1 4))

(setq p1 (entsel "\nSelect data point 1:"))

(setq p1data (entget (car p1)))

(setq p1eb (cdr(assoc 10 p1data)))

(setq r (cdr(assoc 40 p1data)))

;;change the color

(setq x1r (polar p1eb 3.14159 r))

(command "chprop"

(ssget (osnap x1r "qua"))

""

"c"

"red"

""

)

; (princ bdata)

(setq p1e (entsel "\nSelect the elevation of pt 1: "))

(setq p1elev (entget (car p1e)))

(setq p1ee (cdr(assoc 1 p1elev)))

(setq p1el (cdr(assoc 10 p1elev)))

(setq p1ee (atof p1ee))

 

;; pick the second datum point from the contour map

(setq p2 (entsel "\nSelect data point 2:"))

(setq p2data (entget (car p2)))

(setq p2eb (cdr(assoc 10 p2data)))

;;change the color

(setq x2r (polar p2eb 3.14159 r))

(command "chprop"

(ssget (osnap x2r "qua"))

""

"c"

"red"

""

)

(setq p2e (entsel "\nSelect the elevation of pt 2: "))

(setq p2elev (entget (car p2e)))

(setq p2ee (cdr(assoc 1 p2elev)))

(setq p2ee (atof p2ee))

 

;; pick the third datum point from the contour map

(setq p3 (entsel "\nSelect data point 3:"))

(setq p3data (entget (car p3)))

(setq p3eb (cdr(assoc 10 p3data)))

;;change the color

(setq x2r (polar p3eb 3.14159 r))

(command "chprop"

(ssget (osnap x2r "qua"))

""

"c"

"red"

""

)

(setq p3e (entsel "\nSelect the elevation of pt 3: "))

(setq p3elev (entget (car p3e)))

(setq p3ee (cdr(assoc 1 p3elev)))

(setq p3ee (atof p3ee))

 

(datumchk)

)

 

; Run it

(defun C:int ()

(getci)

(gdata)

)

Sorry but I'm just not up to trying this code. Did you see the link I provided earlier re: SiteTopo?

I am blind as well and but now I see the program. I will see what I can do with it. Thank you so much

Well it looked promising anyway.

 

I'm only half-blind. One eye is totally shot. That's why it takes me twice as long to read a post and code just makes my visual orb go all moist. LOL

Lol, hey well if you get it working with autocad, leave a messege on how you did it, i too have been wanting to do this with autocad, but many have said its impossible without other software, 1 thing ive heard of is Rhino, but it cost around 200 i think