Sandbox Struggles

Hi All,

I am attempting to build a topo model using imported contour lines from CAD.
The model is made of four separate groupings of contours. I pre-cleaned the contours in CAD before bringing them into Sketchup.

The four groupings need to align so that we can easily swap the central largest grouping out with various alternatives.

The largest central grouping draped without issue. The smaller groupings however, are showing sharp peaks and valleys rather than a smooth landscape. The file is attached. Any advice would be greatly appreciated Sketchup - Maximum Fill Conditions.skp (7.0 MB)

Are you Draping or using From Contours? You should be doing the latter. Also, before you run From Contours, it would be a good idea to get rid of the straight edges on the sides as they cause the Sandbox Tools confusion. Here I’ve run From Contours on the contours in the foreground.

By the way, I fixed the incorrect tag usage, too. All edges and faces should be untagged in SketchUp. Only groups and components get tags.
Screenshot - 5_10_2021 , 5_06_50 PM

Wow!

Thank you for looking into this. I was using ‘From Contours’ But I assumed the straight lines would help it. I’ll give it another go after deleting them.

I actually don’t know anything about tags. I’ll look this up. Is there a quick way to fix these? Or is the corrected file available for me to use?

Thank you so much for taking the time to help me.

I use a plugin to apply Untagged to raw geometry. It’s called Default Tag Geometry and is available through Sketchucation. Otherwise you can select the geometry and change it to Untagged in entity Info.

Here’s the file. I went ahead and made the terrain surfaces from the other contours and even screwed around making a couple of copies as solids by adding sides and a bottom face.
Sketchup - Maximum Fill Conditions.skp (2.5 MB)

I got identical-looking contours from a local topography data service but they had an option to download a ready-made surface too. IMO the quality was better than what the Sandbox from Contours tool can achieve, with less thin slivers that the Sandbox algorithm seems to make.

Now skip Sandbox and download Fredo Collection Toposhaper. So much better.