Project mesh roads onto terrain

[Михаил_Колесников]

Hello. Help me please. I need to project a mesh of rivers and a lot of roads onto the terrain in an efficient way, and so that they don’t get too buried in the terrain.
I tried to project curves and points, but after that I can’t create a surface.
Seems to work best with “multi move to topo heron”. But anyway, for some reason, in some places the river is heavily buried in the relief, and these sections always move during recompute.

unnamed.gh (25.7 KB)
SRTM and river.7z (1.5 MB)

[ferry59]

@Михаил_Колесников

after that I can’t create a surface

not sure what you mean by that but you can reconstruct those meshes to get closer to the target mesh.

RE01_unnamed.gh (405.9 KB)

btw: it took 192 sec. to load this file, you could internalize your geometry next time

[Joseph_Oster]

@ferry59

you could internalize your geometry next time

When the geometry is extremely large, as this appears to be (I didn’t examine the files), it makes more sense to keep it separate from the GH code, which is usually extremely small by comparison. Otherwise the massive geometry gets copied with every revision of the GH.

[ferry59]

@Joseph_Oster

When the geometry is extremely large

405.9 KB for some internalized meshes doesn’t seem to be extremely large to me.
But in the initial unnamed.gh Heron-Plugin created a huge mesh indeed.

[Joseph_Oster]

The zipped (.7z) file SRTM and river.7z is 1.5 MB so I assumed that its contents are larger when unzipped? But again, I didn’t examine the files. Even 406 KB is rather large, though, compared to the unnamed.gh file at only 26 KB.

And I don’t have the Heron plugin anyway.

[Михаил_Колесников]

Thank you. Sry, I figured out how to internalize the geometry.
internalize.gh (15.1 MB)

It’s not very suitable for my scale. Rivers or roads should not be higher than 2 meters above the terrain, as they will fly over the surrounding objects.

[Joseph_Oster]

internalize.gh (15.1 MB) - A 15 MB GH file is completely ridiculous!!! I rest my case.

Problem with creating item inTekla from Grasshopper's brep

When you have extremely large geometry like this, it’s better IMHO to separate the geometry from the GH code, which is often very small and goes through many revisions. You can do that by referring to a Rhino file for the geometry or use Data Output and Data Input in two GH files, like this:

Insert a small part into a larger model

This idea has made sense to me for a long time so I can’t resist making an example. Geometry is in one file using Data Output with ‘Destination’ set to “Parts geometry_V1”: [Parts geometry_2023Jun11a] Parts geometry_2023Jun11a.gh (2.6 MB) Hopefully that large geometry doesn’t change much. Small GH files that work with it get the geometry using Data Input (black group on left): [Filter Parts by Intersection_2023Jun11b] Filter Parts by Intersection_2023Jun11b.gh (36.9 KB) Voilà!

[Михаил_Колесников]

I’d appreciate your help
3.3dm (1.8 MB)
3.gh (34.5 KB)

[Brian_Washburn]

Hi @Михаил_Колесников
Not quite sure of the intent for the quad remeshing of topography in your original GH, but with a little clean up, MMeshToTopo seems to work.
unnamed_BW.gh (22.7 KB)

-Brian

[ferry59]

I did some refinement on the rivers-meshes and I think I could improve the precision. Maybe to get even closer the terain-mesh should be refined as well.
Another possibility is to cut holes into the terain mesh (extrude the naked river-edges, join, cap) and fill them.

RE01_3.gh (37.3 KB)

[Михаил_Колесников]

thanks to all. Now it seems to me that the matter is in the relief itself.

[Михаил_Колесников]

Yes. I just changed the grid and it started to work much more accurately.

[Михаил_Колесников]

Can you please tell me with what tool you can cut holes in a mesh-surface with another mesh? For some reason it doesn’t work with mesh difference

[ferry59]

using Brian_Washburn’s file I found, that Mesh Split workes fine here. Also Polyline To Mesh from Pufferfish is used.
I solved just 4 of 128 split operations so to cut all of the holes might take some time.

RE01_unnamed_BW.gh (21.8 KB)

[Михаил_Колесников]

thanks!