topic Re: Major Contour label - Identify Major Contour in Civil 3D Forum

Major Contour label - Identify Major Contour

AllenJessup — Tue, 23 Oct 2018 18:20:11 GMT

I was asked a question I couldn't answer. Our Surveyor asked how the Major Contour Label Style determines which are the Major Contours. There is nothing in the style that we can see to filter for those. So I'm thinking it's handled by the software and that's why you need to set one style for major and one style for minor contours.

Re: Major Contour label - Identify Major Contour

jroot — Tue, 23 Oct 2018 18:53:11 GMT

I think it would be determined by your contour interval set in the Style on the Contours tab.

If your Major Interval is set to 10 and you label a contour that is a multiple of that, the Major Label Style is applied.

Re: Major Contour label - Identify Major Contour

kcobabe — Tue, 23 Oct 2018 20:34:41 GMT

I would assume it's handled just like USER contours. If you have them set to a certain parameter in the settings that is when the label style knows that is what it is. I use the USER label style for flood plain labeling. Makes it easier for me to label without using a polyline or something other than the surface.

Re: Major Contour label - Identify Major Contour

BrianHailey — Tue, 23 Oct 2018 21:46:54 GMT

I believe it's controlled via the surface style. If the contour label line crosses a major contour, it uses the major style. If it crosses a minor contour, it uses the minor style. If it crosses a user contour, it uses the user style.

Try it for yourself. Label the surface contours, change the style so the major contours are every 10' instead of 5'. Inspect your contour labels.

Re: Major Contour label - Identify Major Contour

Jeew-m — Wed, 24 Oct 2018 03:08:49 GMT

Dear Allen,

This is an interesting question. Actually what the surveyor asks is how Civil 3D decides which is major and which is minor. If you have 40m to 50m contours he questions how civil 3D selects major contour whether it is 40 or 41 or what ever.

As I tested it follows the image Brian has illustrated.

Let us assume when have a surface with minimum elevation 41 and maximum 65.

If your base elevation is 0 and major contour interval is 5m it counts from 0 with 5m increments . The first number that is equal or greater than minimum elevation and also divisible by 5 is 45. So civil 3D selects 45 as a major contour and defines the rest.

Let us say we changed base elevation as 39. Then Civil 3D counts from 39 with 5m increments. The first to come will be (39+5) = 44. So it selects 44 as a major contour and defines the rest.

Thanks

Re: Major Contour label - Identify Major Contour

AllenJessup — Wed, 24 Oct 2018 13:54:00 GMT

@BrianHailey

I agree the Surface Label Style controls the frequency of the contour labels. However I'm now of the opinion That the Major/Minor labeling is controlled through the Surface Contour Label Group which probably is set up by how the labels are set up. So in this example I have the Major style set to Existing Major Labels and the Minor style set to None.

I haven't been able to spot anything in the Surface Styles that controls the Major/Minor labels.

@Jeew-m

I don't find the " The first to come will be (39+5) = 44. So it selects 44 as a major contour" to be the case. In the example below I moved the Surface down by a foot and then back up. The labels follow the Major Contours as defined by the Surface Style.

This is all supposition. I think it's a combination of the Styles. It's not set specifically in the Surface Style, the Contour Style or the Label Group. It looks like a coordination between them all.

Re: Major Contour label - Identify Major Contour

BrianHailey — Wed, 24 Oct 2018 14:17:34 GMT

The contour label line controls the styles that will be applied to the major, minor, and user contours. The surface style controls which contours are the major and minor contours. The analysis on the surface controls which contours are user contours.

So, in essence, you are correct that it's a combination of the different pieces that control how the labels of the contours look.

Re: Major Contour label - Identify Major Contour

AllenJessup — Wed, 24 Oct 2018 15:33:36 GMT

Thank you for expanding the explanation. I've gone over it with our Surveyor and he seems happy.

Re: Major Contour label - Identify Major Contour

Jeew-m — Thu, 25 Oct 2018 00:39:33 GMT

This video show what I am talking about. I am telling that you can change the value of the major contour to our own value by changing base elevation.

Re: Major Contour label - Identify Major Contour

AllenJessup — Thu, 25 Oct 2018 12:17:50 GMT

OK. I misread your post as simply changing the lowest elevation would change how the program would identify major contours. I see now that you can actually change the "Base Elevation" and affect the labeling and display as you show in your video. I had simply moved the Surface down and up by 1 foot. The display and labeling of the major contours followed the change in elevation. Thanks.