How to compare two nurbs surfaces


#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


(Pascal Golay) #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


(Willem Derks) #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.

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

-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.