Filling 'Holes' in RC airplane model shell?

rhino
patch

#1

Hi, I am hoping to put a 3D model of this 3D printed plane into a flight simulator program before flying it in real life. I’ve attached a picture. There are smaller holes in the fuselage (middle bottom of picture) and large cut-outs in the wings(shown in top left). The physical model gets covered with a plastic film so the holes there won’t matter, but to put the 3D digital model into a simulator program I need the plane to be a solid shape. Is there a convenient way to achieve this in rhino?

best regards,
Dave


(Pascal Golay) #2

Hi Dave - Untrim will be your friend here, possibly UntrimHoles, but exactly the best way to do this depends on the construction - hard to say without the file.

-Pascal


#3

Hi, Pascal,
I’ve attached two of the test pieces. It’s the diamond-shaped cutouts in both that I am trying to patch. I only have the files as STL files initially.Thanks for your helptestpieces.3dm (1.1 MB)


(Pascal Golay) #4

Hello - ugh… you only have meshes - that is a different ball of wax… there is no easy way out of this and even the hard way out … will be a ton of work, I suspect.

-Pascal


#5

As Pascal suggests, there are probably better tools than Rhino for this, but it is do-able if you have to use Rhino.

I would suggest creating a display mode which shows mesh edges, but not mesh wirefame:

Here would be my general workflow. testpieces_SP.3dm (2.7 MB)

Basically, I unweld and weld the mesh until I find a weld angle that shows edges mostly were I would want it to split apart (your mesh actually had pretty good setting to start with). There will be a few areas were I used UnweldEdge to get edges were the weld settings didn’t get them. I then exploded the mesh, and picked the stuff I wanted, and threw out the rest. Join back the result.

In some areas I then used PatchSingleFace to help create closed areas where it would be easy for FillMeshHoles to fill in for me. When PatchSingleFace-ing, I like using a display mode that shows all wires, as it makes it easier to see where to make my picks. Once PatchSingleFace -ed and FillMeshHoles, I look for problems. On your model there were a few areas were FillMeshHoles made some non-manifold mesh edges, so I pulled those out using ExtractNonManifoldMeshEdges, then went back and filled the result with FillMeshHole (no ‘s’ on the end will let you pick a single hole).

There are also some areas were mesh faces fold back on them selves (the areas were you have a random edge in the middle of a smooth area, easiest to see in a display mode where only mesh edges are shown). For those guys I used extractMeshFaces and pulled out some of the faces around the problem area, looking for the problem faces, then fill with FillMeshHoles. When you find a problem area, I find it easier to find and extract the face that is causing problems in a display mode that shows all mesh wires.

It is a pain, but works in a pinch.
Sam