Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

contouring in Autocad

[Subject Prev][Subject Next][Thread Prev][Thread Next]
I have received Survey data as a dwg file of points with 3-D coordinates.
I want to make the contours.
What product does Autodesk have to make contours?
Here is how I have done it in the past.

In summary straight lines are drawn between known elevations. The 3-D face object is used at a given elevation to hide all parts of lines below that elevation. Connecting these line-cuts, with a closed poly-line curve, creates a contour at the linearly interpolated locations between the given elevation points. Following are the steps involved.


   1) Survey points as nodes in 3-D space (x,y,z).

   2) Set nodes to view as a symbol to be seen in plan view. (Format/Point style)

   3) Draw black lines connecting the points, in plan view, snapping to 3-D points, (Tools/Object snap settings / node (only)). Connect all points to all other points surrounding that point.

   4) In plan view, use a separate layer and color red. Draw the contour face; this is to be the elevation plane for locating contours (Draw/Surfaces/3Dface), z default is 0. Place boundaries beyond the image needed.

   5) Switch to elevation view. The nodes will appear as short lines. Move the elevation plane (appears as a red line at z=0) to the desired elevation by modifying the Z coordinates to one elevation. (Modify/Properties/select 3Dface) This same face is to be used for each contour elevation needed.

   6) Switch back to plan view. Run the Hide option. (View/Hide) this will hide lines and parts of lines connecting the elevations that are below the chosen elevation of the 3d Face.

   7) Draw P-line contour using ?snap to nearest? snap   (object snap settings / snap to nearest) (Draw/Polyline) select where lines are cut short by the hidden view that is at the ends that have no node. Make one continuous P=line end at start point by typing the command ?close?

   7) Expose all lines and nodes by regenerating image (View/Regen)

   8) To make a curve Modify P-line to curve. (Modify/Properties/curve-fit) pick the contour P-line and choose (curve-fit).


David Merrick, SE