Hi,
Fixing non manifold edges I explode and join and the top surface vanishes in rhino5
do in 8 and all is good.
why ?
trouble is I have used 8 twice today and twice it hung for over 30 secs just trying to go into shaded mode on this thing. I can’t have that.
rhino5 was instant.
Thats my first experience of comparison, and it lost the match 23 nil !
I want oh wow not oh no.
so back to 5 I go., as I need it to be as good as rhino cant have it hanging like that.
Your object with the claimed lost top face has 3122 surfaces like all original object. It does have naked edges. When I exploded and joined the original non-manifold object there were no naked edges.
I suspect that in removing the non-manifold edges the surface has got screwed (In Rhino non-manifolds come with a health warning). Did you make this in Rhino or import it?
Rhino doesn’t like structures like yours that meet precisely on an edge and require an (in reality, perfectly legitimate) manifold edge, so if you made it in Rhino, I’m impressed.
I don’t see a way to make this work as a single closed polysurface in Rhino without invoking non-manifold edges. Can the slicer accept separate parts and combine them? That would obviate the need for non-manifolds.
Regards
Jeremy
p.s. The slow load in R8 is because it is having to recreate the display mesh. Exactly the same thing happens in R5 if you load your original file there, so don’t feel R8 is letting you down.
Attached is a file with Steve’s object as a single closed polysurface without non-manifold edges. It was created by exploding the original object, then joining all the exploded surfaces. J3Dtech calibration PLATE SR2 45mm rhino5 DC01.3dm (12.2 MB)
That then has broken Steve’s model because non-manifold edges are part of the nature of the object he is modelling and cannot be avoided. It is simply that this is a real-world situation that Rhino cannot model as a single piece without them. The design element is akin to two cubes placed so they touch at a single intersection line coinciding with an edge of each piece - as in a checkerboard pattern. I’m not at my computer, but it would be interesting to dive into the fine detail and see what Rhino has done with them.
I don’t know how Steve got from your exploded and joined model to the misbehaving surface. In my case, I could replicate the problem by merging all coplanar faces, after which the surface became irreversibly problematic.
I am defining “non-manifold” in this thread and the associated thread as the presence of Rhino “non-manifold” edges, not a more general geometric one which considers an object to be non-manifold if three or more surfaces have coincident edge independent of how many edges Rhino considers to be joined. It appears that @jeremy is using the latter.
The model I uploaded has exactly the same geometry as Steve’s model. It has not “broken” Steve’s model. The difference is corners which coincide in Rhino are not joined.
One way to do so, probably not how Steve did it, is to use NonmanifoldMerge on each of the sets of coincident corners. The result should be identical to Steve’s model. The Explode and Join proceedure I used essentially reversed NonmanifoldMergefor this particular topology which is non-manifold solely due to coincident corners. Please note that in the previous thread where I described this proceed I explicitly said:
Hi,
Being asked how did I get the top surface to vanish in both Rhino 5 and 8.
I followed exactly what David had said to do, I took the model I had uploaded here, exploded it then went Ctrl J whilst it was still all selected.
and the top planar surface vanished.
I took it instead into rhino8 and did the same and again top surface vanished, as per image shown.
also as per the file I then uploaded with it missing.
I think I drew the crosses, abutting then incremental gaps etc then extruded.
as for did I create this from scratch, yes, saves risk of using something that might be buggy. though based upon an initial design available to any 3D printer bod wishing to get better results. I added the crosses and extra ski ramp, and numbering and sea urchins. and moved a few things around and added a snap off line to see if the cylinders fitted the holes, and added a chamber under the holes. (correcting the zero overlap in SR4)
