Rebuildng disfigured 3D object in Rhino

rhino5
unhandled

#1

Hi,
I have to restored a 3D scanned model. During scanning process some part of the object is disappeared.
It’s format is ‘.obj’, and appears tris mesh when I open in rhino5. Vanished part is not a plannar surface. It has little curvature, so I don’t know How can I fill these holes and restore to natural foam.

(filling mesh holes tool makes it as a plannar face.)

Thanks!


It is a tomato tree, a perforated ball in front is actually a tomato…

http://postfiles9.naver.net/MjAxNzA3MTRfMTk3/MDAxNTAwMDA1Mzk3MjA3.qyDz1dnSpmhX1_ofVQHp33wtQ9PfRaSM0NgvsOSYQMIg.tWxDBbMlgJbXwagFoZLKR3_UDRrFzKXVSHSEnOvmiq0g.JPEG.1004ooneen/%ED%86%A0%EB%A7%88%ED%86%A0.jpg?type=w2

http://postfiles8.naver.net/MjAxNzA3MTRfMjM2/MDAxNTAwMDA2MDU4ODQ4.7byq1BSh55PDWMZJBR1KSxxGXZNpqAERQ2kEyI_0C4og.F1sxKPpFPtxsHMziB3zV_r-Y3VI29l8wpKzxRmirAiQg.JPEG.1004ooneen/%E3%85%8E%E3%85%8E.jpg?type=w2


#2

If the “broken sphere” is a separate mesh, you can use GrassHopper with a component (named SphereFit) to reconstruct a “full sphere”.

Fig.1. Where to find the SphereFit component in GrassHopper menus :

This component will operate based on the mesh vertices that actually do exist, so be aware of that the input mesh must be resttricted to the spherical part of the mesh. The following components would take the relevent mesh (from the Rhino model) as input, and then “deconstruct” the mesh into it’s parts. It is the points (the vertioces) we are interested in. These points can then be used bu the SphereFit component to reconstruct the missing parts of the broken mesh sphere.

Fig 2. An example mesh and the resutling spehere. This is to show what happens if you include more than the spherical part of the mesh in the input mesh component (the fit-algorithm gets confused by the points being far away from the spherical part) :

You can add to the GrassHopper model some sliders to manually move the resulting sphere in X, Y and Z position to get a near perfect position.

If constraining the mesh to only the part which is part of the sphere, the SphereFit component will be able to output a better result, a better sphere. Like so (using the same mesh as in the picture above, but excluding the irrelevant points that are not part of the sphere) :

Fig.3 Only relevant parts of the mesh is deconstructed here, and the SphereFit result looks more relevant :

// Rolf