Hi new rhino user here.I’m trying to make a CAD file of a mesh ring i made. I’m doing the front part of the ring at the moment.
Practicering1.3dm (12.5 MB)
I made some surfaces by doing edgesrf and trimming a patch they’re on layer 7. How can i join the pieces so its one closed polysurface?
to see the problematic ereas:
_join
_showEdges (naked edges)
to have less work - only build have of the object and mirror it
some of the rigdges don’t meet up:
if your base surfaces is an extrusion or a part of a cylinder - build it as extrusion or cylinder :
not for engineering work - but totally fine for jewellery:
build a flat version of the decor and _flowAlongSrf to get the curved version.
this would be the _flowAlongSrf approach:
the fast flat version is mainly _sweep1.
if you want to have even nicer surfaces / result build all four sided Surfaces with SrfPt or Loft between 2 line (to have untrimmed surfaces for the flowAlongSrf)
hope this helps - kind regards - tom
Hi, I’m doing this jewelery piece to practice reverse engeneering 3D scans. I need to be able to fix the naked edges.
… ok - even if the mesh data is not scanned data…
my go still would be:
find the back-face-profile / section to build it as extrusion.
build the extrusion
_unrollUV
_flowAlongSrf to get a planar representation of the curved geometry / mesh / scan data.
rebuild build the flat representation with SrfPt which will allow maximum edibility.
_flowAlongSrf to get the planar decor back to 3d / curved, do it with history enabled.
finetune the the flat version while comparing the 3d-version with 3d-“pseudo-scan” data.
if you just want to make your surfaces watertight: _join _showEdges … check what is wrong - rebuild the surfaces that can not join. … (first part of my post above)
kind regards -tom
I didn’t have a scanned mesh to hand, so im practising on a high poly mesh I had instead. I have to learn to reverse engineer from scans for work. I’m using the mesh2surface plugin for rhino.
@Fiona_H Have you perviously done 3D modeling in Rhino? In general what type of objects will you be reverse engineering from scans?
I’m newish to rhino, but i’ve 3D modeled in mesh software like Maya blender and 3dsmax. I’ll be doing a variety of things, like for example i’m being asked to do a piece of a dashboard for a car next week. the stuff will be 3D printed so I need the gemetry to be watertight/Manifold.
My recommendation is you take time to learn modeling in Rhino, particularly if you need NURBS surfaces rather than meshes. It’s very different than mesh software like Maya blender and 3dsmax.
“Reverse engineering” a shape in Rhino from scan data is much easier with better results if you know how to build the shape in Rhino.
How closely does the Rhino model need to follow the scan? Does it need to closely follow the scan everywhere? Or are there a few critical areas where the Rhino model needs to match the scan (or other criteris) and elsewhere it needs to be “close enough”? If the Rhino model will be used to refine the shape then modeling with as few control points as possible while still meeting the requirements should be the goal.
A scanned mesh will give you a result that is very different from a meshed nurbs surface.
Typically scans must be cleaned up in advance of using any reverse engineering application. I do not know if Mesh2Surface has these tools, but presenting the issue here indicates that it does not.
Rhino has very limited ability to deal with all the problems resulting from a scanned mesh. The only meshes I have seen straight from the scanning application that are nearly perfect are from CT scans.
