I have a drawing set to UTM83 Zone 14 Meters and my drawing units is set to meters also. I created my surface from my point cloud. When i do the contour extract feature (surface object extract), the contours elevation is in the wrong datum or elevation? The surface contour is 620 but the same extracted contour says 188.97? Curious why this happens. It seems to me that it is back calculate elevation or daturm to a different coodinate system.
senior design tech
You've got a setting somewhere set to feet. Your drawing units are probably set to meters however I'm guessing that the elevation setting under ambient settings is set to feet. Multiplication of 620 by 0.3048 is 188.976, with 0.3048 being the conversion factor from feet to meters.
ok I will change my drawing units to feet and my surface units to meters. Hopefully that will work. So when i extract my contours it should be on the right daturm or elevation.Tks Feckit
Senior Design Tech
When you started this drawing, what template did you use? It's REALLY important to start with a METRIC DWT, if you're going to work in metric values. Just setting units to metric in an imperial template cna hose things up.
I have a question regarding surface contour extraction in Civil 3d 2012.
Based on specifications by our investor we need to deliver contour lines that have intervals like this:
Major 5 m
Minor 1 m
Auxiliary 0.5 m.
Defining the first two was easy, auxiliary required some effort (I created user defined contour lines; fortunately there weren't too many otherwise I would have done it differently). In surface style I assigned each type with a different layer to make it easier to select each type.
Anyway, when extracting contours from the surface, using the above mentioned method I discovered that extracted minor contour lines also included my user defined (auxiliary, at each X.5 m) lines, thus overlapping the actual, and also exported, user defined contour lines. Does anyone know why this happens, and if there is any way to resolve the issue other than removing the user contours from surface definition and then exporting the minor contours, or subsequently deleting excessive minor contours by hand (which I would never do)?
You would normally be better off starting a new thread rather than resurrecting a two-year-old irrelevant conversation.
I don't know why this is happening, but have you tried turning off the user contours, extracting the major and minor, and then turning on only the user contours and extracting them? If that doesn't work I would simply define the Major as 1.0m and the Minor as 0.5m and extract them like that. Then go and find the 5.0m contours and put them on a different layer.
Credit where credit is due! Give kudos or accept as solution whenever you can.
"You would normally be better off starting a new thread rather than resurrecting a two-year-old irrelevant conversation."
First of all: tip dully noted.
"I don't know why this is happening, but have you tried turning off the user contours, extracting the major and minor, and then turning on only the user contours and extracting them? If that doesn't work I would simply define the Major as 1.0m and the Minor as 0.5m and extract them like that. Then go and find the 5.0m contours and put them on a different layer."
Second: I can think of many ways to resolve the problem relatively quickly and efficiently. What I don't understand is why does export minor contours necessarily include user contours (whether they are displayed or not doesn't matter as long as they are created/defined in surface properties as I have already discovered). Since I will need this a lot in my project and will thus encounter the same issue many times during this project I would prefer to have autocad do what it (by all reasoning) should do, and that is why I sought help here. If there is no solution I will be a bit disappointed but at least I will have tried my best to find one.
Maybe if You think of something else or know someone else who could help, You could let me know.
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