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    by Geoff Woodhead

    It’s been a good week for me with regards to getting my Civil 3D installation just the way I want it. There was just one graphical issue left for me, perhaps some of you have seen it before. When applying a Slope Marking style to a Grading with a feature line that is non-flat the head of the tadpole is projected to the origin point of the file (see fig. 1 & 2 below).

    Fig. 1

    (Slope Markings attached to a non-flat feature line)

    Fig. 2

    (Slope Markings are shown at the origin rather than attached to the feature line)

    This one was a strange one, my initial thinking was that Civil 3D was having a hard time when using an AutoCAD Block in a Slope Marking style. A little bit of playing around with the UKIE country kit quickly disproved this theory as I found a Slope Marking style that applies an AutoCAD Block and works where this one doesn’t. My next thought path was that one of the parameters that govern the composition of the Slope Marking was to blame. A comparison between the style that didn’t work and the one that did didn’t flag anything up. The only thing I could think of was that something inside the block being applied was to blame. Upon examining the block that wasn’t working I was presented with one Polyline and one Line, nothing out of the ordinary here, I also checked to see the object type of the tadpole head, it was the Polyline. Next up I checked the block that attached to the feature line correctly, this one contained one Line, one Hatch, one Polyline and one 2D Polyline. The objects that are displaying as expected in this block are the Line, Hatch and 2D Polyline. Could this mean that the problem was with using Polyline’s in AutoCAD Blocks that are applied to feature lines? Let’s put it to the test!

    1. Type BEDIT -> Press Return
    2. Select Tadpole 2 and press OK
    3. Type CONVERTPOLY -> Press Return -> Select Heavy from the command line options -> Select the Polyline that forms the Tadpole’s Head -> Press Return
    4. You should now have a 2D Polyline, Save the block and exit the editor.


    Your tadpoles should now correctly display their Head’s (see fig. 3 below) even if they are applied to a feature line that is not flat! It seems that the weight of the Polyline affects its ability to anchor to a feature line, my advice for if you are creating your own Slope Marking styles is to use 2D Polylines (Heavy Polylines) in the AutoCAD Block so that they do not float off to areas you don’t want them to be.

    Fig. 3

    (Slope Markings are shown at the origin rather than attached to the feature line)

    I have applied the changes listed above to my UKIE drawing template file so that this is fixed on every new drawing I start, if you have been experiencing the same issues as me it is probably worth doing the same.

    That has made me one happy chappy for the start of the Bank Holiday weekend, now all I need is the download for the localised Infrastructure Design Suite to become available!


    Comments from our old site

    25 Sep 2014 15:02

    vivhowe said:

    Just been scratching my head over this problem myself, got so far as realising that non level feature lines were causing the problem. Your solution works great on linear feature lines but not, unfortunately, on non-linear e.g. faceted or curved.
    Thanks for your insight.


1 comment

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    Michael Campbell

    Thanks for this fix, it worked a treat. The only issue I'm now having is when I export my civil 3d model into 2d autocad format. The issue tadpoles do not export properly and when exported a tadpole is found at 0,0.

    Is there any way around this?





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