So, you like to use the Bearing and Distance command while drafting in Civil 3D you say? Well, you might want to be aware of a little inconsistency in the command depending on how you run it.

Rick Ellis over at Cadapult Software Solutions (the author of the Civil 3D book we use here at CAD-1) pointed this out to me and I thought it would warrant a blog post. Thanks Rick!

So, here’s the problem, two lines drawn from the same location using the Bearing and Distance transparent command end up with different bearings depending on how you run the Bearing and Distance command.

Different Results, Same Input

Different Results, Same Input

So, what did I do differently? Well, the bottom line I drew using the Bearing and Distance command by typing ‘BD at the command line (don’t forget the apostrophe). The top line I drew it using the Bearing and Distance command from the Transparent Commands Toolbar (by default on the right side of your drawing area).

This will make more sense if I explain what it is I typed. I start the line command and snap to the center of the circle. I then invoke the Bearing and Distance transparent command using one of the methods listed above (repeat with the other method). I then type “1” for the quadrant, “45.4545” for the bearing, and “100.00” for the distance.

Same input different results

Same input different results

That’s great and all but, which one is wrong? Well, technically, they are both right, they’re just different. When ‘BD is typed at the command line, and you input 45.4545 for the bearing, it sees that as 45o45’45”. when you use the Bearing and Distance command from the toolbar, you are actually using the ‘_BD command and it returns a bearing of 45.4545o which, as you can see in the video, works out to be about 45o27’16”. Neither is wrong, they’re just different.

Here is a video with commentary that I made if you want some additional clarification:

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