Creating a clean orthogonal grid mesh on a non-orthangonal object (GECO)

Hi all...

I am trying to create a clean grid on a non-orthogonal object. The basic idea is that I've got several "floor plate" curves that define each level. They start as rectangles but are deformed into angular plates at some points. The curves are extruded into volumes and stacked. I am using Mesh from Surface to create a grid mesh on each surface.

The problem is that I get these overhangs of the mesh beyond the edges of the object, which I suspect results from the UV coordinates of the surface overhanging the trim surface. I tried to recreate using Point grid on surface and even evaluate surface by uv points but with the same results. These overhangs are then interfering with my Ecotect calculations and are generally unsightly and incorrect.

Any tips on creating a nice clean mesh from this? I don't want a triangulated and subdivided mesh, but something that approximates an orthogonal grid.

Thanks,

Marc

Replies to This Discussion

Permalink Reply by Jon Mirtschin on May 28, 2011 at 1:21am

Hi Marc,

I guess there are a couple of options, you can set the overhang to false and reduce the mesh intervals until it "approximates" the surface adequately. Of course increasing faces will influence ecotect computation time.

I haven't come up with a native Grasshopper strategy that would work generically, it might be possible to do so for a particular surface. I have attached another option, StructDrawRhino contains utilities for sorting curve networks and can produce a mesh from this. I haven't tested too rigorously for reentrant corners, so if you use it and it if "breaks" in a particular scenario, let me know and I will improve it. I just uploaded a new build with improvements to produce this result.

Hope it might help,

Jon

Attachments:

generate mesh.gh, 29 KB

Permalink Reply by to] on May 28, 2011 at 2:55am

Hi Marc,

Sorry for answering a bit late,....but i am sure you forgive me(totally busy)

We have provided a example where you can use the in-build Measure-plane from Ecotect. You can just send a simple triangulated mesh-floor to ecotect and retrieve a Mesh which fits you boundaries,....something like Jon proposed.

Take a look on this page it is the last example FormFitGrid http://www.grasshopper3d.com/group/geco/forum/topics/example-files-...

cheers

to]

Permalink Reply by Marc Syp on May 28, 2011 at 11:54am

Thanks guys, I will check out both methods. In the meantime, I was able to generate a hybrid mesh that worked pretty well. Because I don't need the same kind of analysis resolution on the horizontal sections as I do on the vertical, I was able to sort them into two groups. The vertical group works quite well with surface meshing because there is no UV creep, whereas the horizontal meshes work great with Brep meshing with no overlap.

That FormFitGrid definition looks like it will come in handy with more complex forms, so I will definitely check that out. Also, I need to check out GeometryGym in general, but that might have to wait a bit longer until I get some free time...