Elevation data in Rhino?

[Helvetosaur]

@cwreckord

but then the surface that was created was much larger than the original, even though I specified a box the size of the original mesh.

Hmm, that seems odd, it should create a surface the size of the box drawn ( I assume from the Top view)…

@cwreckord

I am not sure if I am trying to create a surface with too many points (that would be my guess)

Drape seems to have a limit of around 846 points in each direction - don’t know why that odd number, but here (Windows Rhino) it makes that in a few seconds, no problem. If I ask for more points than that in either direction it just brings it back to 846.

Are you sure you’re not confusing Patch and Drape?

–Mitch

[cwreckord (Courtney Reckord)]

@Helvetosaur

rape seems to have a limit of around 846 points in each direction - don’t know why that odd number, but here (Windows Rhino) it makes that in a few seconds, no problem. If I ask for more points than that in either direction it just brings it back to 846.

Are you sure you’re not confusing Patch and Drape?

Hi Mitch! Definitely sure I am using Drape. Maybe I will try it again with something else.
Thanks!
Courtney

[cwreckord (Courtney Reckord)]

@Helvetosaur

What do you have as input data? A script would be for importing point coordinate data contained in organized rows/columns like an ASCII Grid format

Hi Mitch,
Thanks so much for all your help. There are a lot of possibilities out there, which is part of why this is so hard for me. I am not sure which data set to use- USGS has ArcGrid, ArcFloat, LiDAR and SRTM data. It’s overwhelming!

[Helvetosaur]

@cwreckord

USGS has ArcGrid, ArcFloat, LiDAR and SRTM data.

Yeah, unfortunately none of those is a text format, they’re all proprietary. You will probably need to run the data through some other software package (QGis has been mentioned) and export something that Rhino can import. I have an importer for ASCII Grid files (text) which can create a surface from the point grid on import.

–Mitch

[cwreckord (Courtney Reckord)]

ok great. Thanks for clarifying!

[djordje]

Thank you @wim .

@cwreckord

Here you go! This is the most recent version! Courtney

Round ring fillet edges size 7.5.3dm (6.2 MB)

@cwreckord Can you attach you initial topography file please (.tif, .img, .asc, .hgt…)?

[jet]

I think I have a similar question, I can go start a new topic if not.

I suspect there is an easy way to do this and I’m missing the obvious. A surveyor passed me a DWG file that has an elevation map in one layer. The elevation data is polylines with elevation in the Z-plane, then there’s a 2d drawing on a different layer with the boundaries of a property. What I’m trying to do is clip the elevation lines within the boundary line and convert the clipped line in to an object for rendering. I might end up doing this often and I’m willing to write a Python macro if that’s a better route, but suggestions or pointers are appreciated.

[Helvetosaur]

Well, you can trim the contour lines with the boundary in top view (apparent intersections=yes) with normal Trim command and a few crossing window selections. I have also attached a script for an automatic boundary trim below.

@jet

convert the clipped line in to an object for rendering.

I assume that you want some sort of terrain surface - this is usually a mesh and the easiest way to try and create it might be the MeshPatch command. Otherwise, in the WIP with Grasshopper (ExplicitHistory), you can extract the vertices from the polylines and run them into the Delaunay component.

HTH, --Mitch

MultiNestedBoundaryTrimCurves.py (4.1 KB)

[jet]

@Helvetosaur

(apparent intersections=yes)

d’oh. I was trying to do it with Split and booleans.

[cwreckord (Courtney Reckord)]

@Helvetosaur

Yes, I feel your pain. Working with complex meshes in Rhino is difficult (sometimes impossible). For terrain meshes, if you want to do Boolean operations and the like and you are going to do them often, you are better off having some kind of terrain-specific software - like RhinoTerrain. It’s not cheap however.

So, @Helvetosaur I am still working on this problem. I did end up being able to import the hgt files from USGS using the Elk plugin for Grasshopper (windows only) and then ended up with a series of curves. I am working on making those into a surface. It’s slow going and rhino keeps crashing so I believe I might need to go another direction. You said RhinoTerrain makes it easier to work with large complex meshes and you can still manipulate the mesh?

[Helvetosaur]

@cwreckord

then ended up with a series of curves. I am working on making those into a surface. It’s slow going and rhino keeps crashing

How are you doing this? What are the curves like? Surface or mesh?

If you have the Rhino for Mac WIP (or Windows Rhino), you can use the Grasshopper Delaunay component to create a terrain mesh with either your height points directly or by extracting points from the curves via different methods. This is generally not a real strain on Rhino and should not crash it - I guess it depends somewhat on the number of points.

Once you actually have the terrain mesh in Rhino it should not be a problem to visualize in Rendered mode - I have terrain meshes here with many millions of polygons, and they display fine as long as I don’t show the mesh wireframe. However, editing them is something else.

RhinoTerrain does make it easier to work on complex terrain meshes - trimming, Boolean operations, etc.

–Mitch

[cwreckord (Courtney Reckord)]

@Helvetosaur

How are you doing this? What are the curves like? Surface or mesh?

Hi @Helvetosaur I am using the Elk plugin and generating a series of curves- they are not mesh curves but I guess surface curves. Then I used the Network Surface command using every other curve because using each one was crashing rhino!