Typically, GIS data in the form of Topographic Contours or Points are used to create a surface. <<Your data may vary.>> Somewhere, someplace you are missing a step OR performing a step incorrectly.
1. Begin the surface creation procedure.
2. Give your surface a NAME. (Optional: Give your surface a description.)
3. Browse to and select your contour shapefile. This example uses a topographic contour shapefile.
4. Check the box next to the Feature Class (contour line shapefile).
5. You may, or may not, decide to check Define area of interest by which will LIMIT the data you'll use to generate the TINN surface. If you don't check the box, C3D won't limit and will use ALL the data even if the data covers more the the target TINN area.
Example: You use 100% of the data even though you only need 8%, this means you have 92% EXTRA Tinn surface that you won't display in your viewport but generated anyway because you chose not to 'limit the data.' Devoting resources to create a TINN bigger than what than what you'll display in your VP is not efficient Cad management.
6. This is where you to tell Civil 3D how to RAISE each contour to its proper elevation. By default, contour shapefile using this Civil 3D procedure will be at 0-feet (mean sea level) despite the GIS data indicating it has an elevation value. The GIS value is for informative purposes only, meaning the values look 'nice' when viewed in a Table. It doesn't mean your contour is PHYSICALLY elevated above sea level! You want (the C3D creation process wants it too), contours that are 'raised' up to their corresponding elevation so the surface creation process can create a TINN with proper elevations, not a flat surface at sea level. Don't get me wrong, DATA values (any data values) in a Table are NOT useless or meaningless. When used with know-how can perform analytical functions beyond the scope of Civil 3D.
Performing 1 thru 6 correctly will create a TINN.
Chicagolooper
Giulia,
Using "Create Surface from GIS Data" I get same as you: "No GIS Data".
Another work flow is called for. Try >>>This Way<<< starting at 0:40.
"what is the difference between 'background' and 'design,' and between '1' and 5'' and '2' and 10''?"
The only difference I can see between Background and Design is choice of contour colors.
1'(Minor) and 5'(Major) Contours
2'(Minor) and 10'(Major) Contours
Dave
Dave Stoll
Las Vegas, Nevada
NVIDIA Quadro P5000 16GB
Windows 10 Pro 64 / Civil 3D 2024
... and the numbers refer to the minor and major contour intervals,
neilyj (No connection with Autodesk other than using the products in the real world)
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<<...the difference between 'background' and 'design'>...>
The difference between background and design is the appearance Civil 3D gives the surface. Typically, the contour shapes and directions of Background is different compared to Design. This difference helps the user, or the designer, to differentiate between the existing surface and the proposed surface. For example, an untouched field with natural vegetation may need a new surface for future development. The design surface would help field personnel to perform their cut-and-fill (or excavation) using heavy machinery. When the proposed design contours are superimposed on the existing contours, the difference in appearance provides the opportunity to visually compare the existing vs. proposed.
IMHO, I don't agree with the color choices made by Civil3D--the colors of existing and proposed are too similar. Fortunately, C3D gives you the ability to change the colors so existing vs. proposed can have a more striking contrast.
<<...between '1' and 5'' and '2' and 10''?>>
The difference is the contour intervals. The first number represents the contour interval. For example, contours may change every 1-meter and the lines represent where the elevation 'changes' from one level to the next. Generally speaking, tightly spaced contours means elevation changes frequently and may represent steep slopes whereas infrequent widely spaced contours represent flat terrain. MAJOR contours also have a different color than MINOR contours, such as green for Major and pink for Minor. Major contours can occur every 5, 10, or 25. C3D allows you to change the contour intervals and major & minor colors.
I had no problem creating a surface from your uploaded shapefile so I can't say Civil3D's process is flawed. It might be (or might not be) user error. Make sure you HARVEST the correct elevation values from the shapefile's database file (dbf). The mechanism to harvest the elevations in the Create Surface from GIS Data workflow is called Data Mapping. (Refer to Data Mapping in image below.) The harvesting process is built into the workflow and is shown highlighted in blue.
The attribute in the shapefile you need is named ELEVATION. See Left column. This attribute will be used by Civil3D as an 'definition' for your surface. Mapping the elevation is Civil3D's way of saying, 'OK, thank you for letting me know where to get the data.....now what do you want me to do with those values?' The Right column says, 'Mr. Civil3D, you're welcome, now please use those attributes as surface ELEVATION when you build my surface.'
The procedure already knows which attribute value corresponds to which individual contour line. With proper Data Mapping the shapefile's database is leveraged to build you surface using the correct elevations.
NOTE:
FYI, I don't think UTM84-32N is the correct projection because your contours do NOT land in Italy. Turn on Bing Hybrid and you’ll
see your contours are too far east compared to Bing.
Is your site Motta Visconti? I don't believe the author of the shapefile used UTM84-32N.
Chicagolooper
Thank you, but even if I assign the "elevation" field to the shapefile field, I still get an error. The only thing that doesn’t add up when I try to load the shapefile is the coordinates: even in the example responses you’ve provided, there’s always a summary of the coordinates in the bottom left, but for me, it always says "no datum" Meanwhile, in the top right, as you can see, I have a different coordinate system than yours.
Hi Giulia,
Recommend you get different data to build your surface. What is the approximate location(Latitude/Longitude) of your Area of Interest? There's tons of free data available for most of the earth.
Dave
Dave Stoll
Las Vegas, Nevada
NVIDIA Quadro P5000 16GB
Windows 10 Pro 64 / Civil 3D 2024
What do you mean by using different data to build the surface? My area of interest is the municipality of "Casorate Primo." I think the issue lies with the coordinates, though I’m not sure if this could be the reason behind the "No GIS Data" problem. Here, as you can see from the ArcGIS screenshot, the coordinates for the DTM are in WGS84 32N.
However, when I try to simply load the DTM into Civil, it appears that there is no coordinate information available in the file to import.
What could be the cause of the issue? I can also upload the DTM.
Thank you
Giulia,
Not sure what the issue is. I even tried with other data from >>>Here<<<. (I wasn't able to find good hi-rez elevation data for Casorate Primo.)
Thanks for posting your DTM. You can add that Tiff directly to your TIN Surface Definition.
As for showing "Map Coordinate System" as "unknown", use Command MAPCSASSIGN to assign EPSG:32632, UTM84-32N, to your drawing first thing.
Edit: I didn't show that I excluded elevations less than 90 meters.
Dave
Dave Stoll
Las Vegas, Nevada
NVIDIA Quadro P5000 16GB
Windows 10 Pro 64 / Civil 3D 2024
@giulia_lussanaAWHRM wrote
<<...there’s always a summary of the coordinates in the bottom left, but for me, it always says "no datum" ...>>
The coordinate system displayed at top right is the native coordinate system given to the data by the data's original author while the coordinate system the you have assigned to modelspace is displayed at the bottom left.....AutoCAD will display No Datum, No Projection.
...
Chicagolooper
I'd also recommend enabling the MAPSTATUSBAR in Civil 3D so you can see where you are in the world
neilyj (No connection with Autodesk other than using the products in the real world)
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Make sure your shapefile is using the native coordinate system given by the shapefile's original author. Use Monte Mario / Italy zone 1. Refer to Image-1.
You also wrote:
<<... even if I assign the "elevation" field to the shapefile field, I still get an error...>>
The shapefile's elevation values are stored in the DBF (database file). Refer to Image-2.
Before building your surface, use the command MAPCSASSIGN to assign UTM84-32N to your drawing's modelspace. Add your shapefile named contour_line_2 after you've established the drawing's CS.
It's perfectly OK for your shapefile to use its native CS (Monte Mario/ Italy zone 1) while your modelspace has UTM84-32N.
Casorate Primo, correct? Refer to Image-3.
Chicagolooper
