Daylight Line Tip

From the Ground Up did a post today on “How to create a flood plain – Tip and Trick” and it reminded me of a post I should of done last October after the Blogger’s Day event. Essentially its an easy way to extract the daylight line between two surfaces without creating a volume surface.

Now for this post, to get the most out of it, start with the From the Ground Up post and come back to this post once you get to the part about making a volume surface (Step 4).

It all make sense? Good. Now utilize this Step 4 instead.

Go to the Analyze Tab on the ribbon and select the Minimum Distance Between Surfaces (for Civil 3D 2011, for 2010 you’ll find it in the Toolbox under subscription if its downloaded and installed). 

When you run the command utilize No and choose to draw the intersection as an AutoCAD polyline(s).

Now go back to From the Ground Up and continue on to Step 8. So the command has removed 4 steps out of the original process.

While not dynamic, chances are you are getting the flood plain elevation from the Engineer or other software package so it shouldn’t be a problem. If you do need it to be dynamic and you plan on testing a bunch of elevations out, the other method may be better. It all depends on what you are doing.