Surface Labels "contour line only"

[ebaker72.eb]

I know its been years and years that applying the "contour line only" to surface labels makes files basically unusable, but has anyone ever figured out a workaround for this? Seems wild that our only choices in 2026 are still either contour labels with lines running through them, or unusable files.

[AdammReilly]

I have used the 'contour line only' option a lot and I don't recall there ever being an issue that made the file unusable.

What specifically makes it unusable for you?

[ianjchap]

Hi @ebaker72.eb,

To help, for the 'Contour Multiple' labels you can turn off the Minor labels in the Properties. This helps reduce too much label clutter if that's an issue. And will update on any Major Contours if the surface design changes.

[ebaker72.eb]

In most cases for my work, labeling all contours is preferred. I agree though, only masking/labeling major contours helps, but it still really bogs down the file and I find myself staring at the blue "displaying contours" bar far longer than getting things done. Some of my projects are dozens of acres and its not always practical when I have so many blow-up areas. 

[ebaker72.eb]

As soon as I apply contours only to surface labels in properties, the file immediately becomes bogged down. Any switch from model to paper space, regens, etc. results in a very slow moving and repetitive "displaying contours" bar. And actually grading, using corridors and grading objects...forget it. I spend more time waiting for that bar to stop than I do actually getting work done. If I switch back to "from label style," the file goes back to running smoothly. Its been annoying me and generating township comments for many years now. Then I have to explain to my boss why civil 3d can't clearly show contour labels without destroying productivity and that we have to choose between those two options. 

I also know its not my machine because I built a top of the line $4.3k machine, and this has been an issue for me at 2 different companies, as well as my independent gig, going back to at least 2018.

[andrew.schroeder · Accepted solution]

@AdammReilly You're not wrong, there is definitely a performance hit with only masking contours.  Similarly, if you draw a "line" to indicate the contour label placement, the number of vertices has an impact as well.

I don't have a solution for this issue specifically, but I'll suggest a workaround if these township plans you're generating are displaying existing contours.  Typically in the GIS world we'd display labels at an interval along the contours, which would appear randomly across the spatial extents of the plan.  If the surface you're labeling is static/not updated frequently, using my easy 32-step process you can:

1. Generate the contours text as labels, with a box around the label (in the label style),
2. Explode the surface contours and resulting labels, place the boxes on their own layer using QSELECT
3. Use MAPTRIM to clip out the portions of the contours within the label boxes
4. Use MAPCLEAN to weed the contours to an acceptable density for the scale you're working at.

You'll have a very performant, static reference where no matter your AOI, it's got coverage for within the viewport.  You can also still have the original surface in there (not displaying contours) for profiles, spot elevations, targeting, etc.

One other tip that I find looks good, is to use the water drop tool to generate the contour label polyline/path which emulates a more cartographic output.  But due to the many vertices the waterdrop tool creates, be sure to weed those lines via MAPTRIM first.

[jroot]

I think we had this early on in the early C3D versions.

Have you tried editing the Surface Style...Contours tab...set Contour Smoothing to False ?

[ebaker72.eb]

Interesting. I appreciate those tips. I like the idea of exploding the surface and keeping the existing surface invisible. I do sometimes have to update the existing surface when construction has taken place during the process, but it seems like it'd be easy enough to update. Thanks for that.

Also, I chuckled at your "easy 32-step process"

[jpopePXAJJ]

Do the settings, Masking: "From Label Style" and Display Contour Label Line: "False" not give the desired result? I only use the "Contour Line Only" setting for when I have an aerial in the background due to the performance issues with large surfaces. Mostly LiDAR generated ones.

[tboehler · Accepted solution]

You can use the Extract Objects command instead of exploding the surface - for contours.   Very easy to use.  I use Andrew's method for many of my projects.   Extract the contours and make a topo XREF for all drawings.  Contour layers for 50-ft, 10-ft, and 2-ft to display is needed for appropriate scales.. The contour labels are annotative text (sometimes with a background mask sometimes not).  The surface is then added as a Data Reference if needed (No Display style).

[navya_gelli]

Hi @ebaker72.eb ,

I wanted to check in and see if you still needed assistance, or if andrew.schroeder helped resolve your question? Let us know if you need further assistance by providing an update or if you have found a solution, please share it with the community so other members who may have the same question could learn from your experience.