Creating a Surface from 3D Polylines

Hey all, right now I am currently trying to create a surface from a series of contours which I presume has been created before then exploded. So right now I have a series of 3D polylines with labels. I went through the steps to create a surface and add polylines, and AutoCAD tells me it was successful. However, once I tell AutoCAD to add contours to the surface it sends me a message listing every line and telling me they could not be created due to each individual line crossing a breakline. So, my end result is a surface with nothing in it. The only layers I have turned on are the index and supplementary contour layers, so those are the only lines I select when designating the contours. Any help would be greatly appreciated.

You can try going into the Surface Properties -> Definition tab, and change the build properties so that the surface allows crossing breaklines. That might give you something better.

But if the lines you're using are actually contours, they shouldn't be crossing... And each contour should be at a single elevation along the entire length of the polyline, so contours usually are not 3D polylines. They're usually normal polylines, set to an elevation. So if all of your lines are 3D polylines that are crossing each other, I'm suspicious about them. They don't actually sound like contours. Either that, or you may have some other issue going on as well.

Ok, you were correct they are not 3D polylines but actually polylines set at an elevation, my mistake. I did come across another problem though. I cannot add the contours to the surface when using the file and just turning off all the other layers. I can however create a surface if i copy those contours and open up a blank autocad file and paste them there. (This works when following your earlier advice to allow crossing breaklines) Is this a template issue or something else thats preventing me to work in the original file? I can post the file if you would like.

Easiest thing is to post the file. That helps eliminate the guesswork.

Hey all, right now I am currently trying to create a surface from a series of contours which I presume has been created before then exploded. So right now I have a series of 3D polylines with labels. I went through the steps to create a surface and add polylines, and AutoCAD tells me it was successful.

Can you tell me the steps for this?

Have you looked at the Tutorials that ship with the product? They cover a lot of this basic information moderately well, with step-by-step instructions.

Maybe explode all the polylines into lines then Toolspace, surfaces, add definitions, drawing objects, choose lines, maintain edges. This should work if your lines have a Z value. Breaklines not a problem.

Only thing is recreating contours never quite match original surface from contour exported lines but are better than nothing.