Hi everyone,
I’m trying to figure out how to build the most accurate terrainmesh in rhino, in order to make a mesh where I can get “correct” (precise) spot-coordinates as well as fall lines on a mesh.
In my test I’m starting out with a survey with meassured curves and the points from the real world. The survey meassured curves along the boundary of the area or a building that cannot be moved, as well as specific points. and from there we define the new important fall lines using points and curves.
In the test I’ve been using these plugins: Lands, bison and Land-kit, as well as pufferfish. (just for the script to work for everyone) as well as the default delaunay in GH.
Modelling terrains in rhino can be a bit tricky balancing between “exact” and “something that looks right”
This is also an open discussing on how precise you guys build your terrain in order for it to work with for example flow lines of the rain water?
As input i’m using the 3D curves and the 3D points from the survey.
In bison I tried to use the “standard” procedure, without dividing the curves into points pr xx meter. Only letting Bison use the 3D curves and the 3D points.
And as a second procedure, i’m dividing the curves into points pr xx meter, and I use the controlpoints (kinks) of the curves + the 3D points. This one is used for all of the four methods: LAnd_kit, Delaunay, Lands and Bison.
It looks like Land_kit, Delaunay and Bison are using a similiar method to build the mesh, but Lands is making the terrain become less precise by using “quad-triangles” (don’t know the exact word) instead of triangles,
Lands - “Quad-triangles”
Delaunay, Land_Kit and Bison:
I can see why its smart to create a quad-triangled terrain, to the make the mesh easier to split as well as creating a more natural landscape, but it would be nice if the terrain follows the survey more directly, especially in projects where there’s a building inside the project area.
In Lands there’s a restriction of 0.5m for the gridsize of the “quads”, but is it possible to make this more strict? Or somehow make some curves more important than others?
I think this is what Land_kit is trying to do by letting the user add different objects such as breaklines into the “mesh-builder”:
Another more general question is how much I need to divide the curves in order to get a precise terrainmesh that I can trust? Any good experiences to share? I normaly use 0.5m, but this gives a quite “complex” mesh to work with. In the GH I tested with 2m.
Especially if I want to divide the terrainmesh into roads, path etc. This gets tricky with a mesh, when its too that precise. I guess rhino is having a hard time splitting the mesh.
But this is where the Lands terrain is doing really good. It’s easy to divide, but the Lands mesh is not strict enough to follow the survey points and curves. The transformation from triangles to “quad-triangles” makes it not as precise.
I hope some of you wants to discuss this in an open discussion
There’s probably a lot of things that I miss on the way, in order to understand the “mesh-building” possiblities and limits.
I’ve attached my testmodel both Rhino and GH. I hope it’s easy to understand what’s happening inside GH. In the Gh I use contours, a projected point and a fall line in order to check the meshes.
test-survey_m.3dm (1.2 MB)
MESH-testing-landscape.gh (152.8 KB)
Cheers,
Thomas