How to compare two nurbs surfaces

Rhino Rhino for Windows
1

I recreated a surface and wish to compare how they compare with each other. Is there any tool in Rhino (or outside) to that purpuse?

The file with example is here: https://www.dropbox.com/s/q11x6158nnigzbk/Compare_Surfaces.3dm.

Thanks a lot!

Ricardo

2

Hi Ricardo- one way would be to mesh one of the surfaces and use PointDeviation between the mesh and the other surface. I guess I’d not make the mesh too dense for this.

-Pascal

3

Hi Ricardo,

yes, your second surface is much better. If your question is how much the better surface deviates from the original one: it’s about 0.03mm. The VSR Shape Modeling plug-in offers a lot of analysis to compare or analyze surfaces:

http://www.virtualshape.com/en/download

Let me know if you are interested in more information.

Cheers,
Michael

4

Hi Ricardo,

I have a MeshMesh deviation tool to create a colored pointcloud indicating the deviation of 2 meshes.
You could use that by first meshing the surfaces and than checking the meshes.
It’s not very complicated to do this directly with the surfaces, yet I needed it for meshes, I have no time to re-write it now unfortunately.

mmdev.jpg
mmdev.jpg916×741

You might want to adjust the display of a pointcloud like so:

ptcloudsize.jpg
ptcloudsize.jpg1003×564

-Willem

5

Thanks to all. I have used PointDeviation by extracting the analysismesh and putting it over the other surface and it seems to work fine.

I have also downloaded VSR tools to try it out but i think some of the surfaces I am working on are very poorly defined so I am correcting them beforehand.

6

Hi, Willem. Can you share the rvb file. Thanks!

7

Hi,

From my archive:
MeshMeshDeviation_03_wd.rvb (7.3 KB)

-Willem

1 Like
8

Thank you! Willem.

-Joann