Hi Guys
I have a problem with some of my curves. When I extrude the curves, the extrusion is not smooth at all like it should be. It is staggered and very kinky.
I’m not far away from the origin (i know that i can have this problem if i move the geometry very far away, but it is not the case).
I tried make a curve boolean of the curve (is a close curve), and rebuild it. But even then, if I extrude, I will have a not usable extrusion.
If I make a brand new curve from scratch, the problem disappear. But the point is, I can t do that, I need to somehow use the geometry I already have, and fix it!
Can please anyone help?
please help!!! 
Check - and change - your mesh settings. If they are set at ‘Jagged and faster’, try setting them to ‘Smooth and slower’. Else set to ‘Custom’ and if necessary, go into the detailed controls.
Thanks Wim
however I tried that already
it fix the problem partially. it looks better but still with kinkies.
Can you post a part of that file?
sure
here the file
wait a sec…
here the file
Download link
It doesn’t look like the surfaces that are most affected by this are included in the file (the stripes in the floor and ceiling) but anyway…
I changed the
Maximum distance, edge to surface setting in the mesh settings and noticed that the meshes weren’t being regenerated. Try using ClearAllMeshes first, then change that setting and then switch to a shaded mode to see if that helps.
curve.3dm (1.5 MB)
does not help…here the file with the curve, here the problem is even worst
…
Hi Riccardo,
This object is an Extrusion and is not affected by any mesh settings @Pascal this looks like a bug to me. No matter what mesh setting I use the extrusion will remain jagged.
Riccardo, use the command ConvertExtrusion. That will make the object in a polysurface and mesh settings will affect this objects mesh.
HTH
-Willem
thanks
convert extrusion unluckily does not help much.
I will live with that.
I would still love to understand what the problem is
thx
Ric
For now, if you have converted the extrusion, you can use a custom mesh on it, by selecting the object, getting its properties, and selecting a custom mesh. Though, it’s not the density we are after in this case, because the seems to deal with resolving details.
In the mesh settings, I would set:
The maximum edge length to something like a 50 millimeters to start, and work your way down.
The maximum aspect ratio, working your way down to one.
And perhaps the maximum angle to 45 degrees.
(These later two makes nicer meshes for 3D printing .stl’s. I limit the edge length to about the printer’s step resolution, or the printing and slicing time go like crazy.)
Before:
After meshing, but still an extrusion:
After Converting:
Notice that we are still at 50mm for maximum edge length, for final rendering you could go down lower, but things are going to get slow. I left it large enough so it doesn’t look like a solid mass of orange, so we can see the quads.
The minimum edge length can be higher than you had. We want the longest edges shorter; but they should still be bigger than we can see.
It’s interesting that the aspect ratio has no visible effect on the extrusion endcaps (not the side fan which isn’t much of a fan really because it shows quads, but fans are the kind of stuff graphic cards like to render).
As a polysurface, we can also subdivide the endcaps, which in theory, would make better renders, because long thin shards breed rending artifacts, because there are limits to rendering sorting and z-buffering accuracy. According to an old graphics book I had, the nightmare for a renderer can be as simple as a peice of paper with a pencil jammed though it at an angle. What’s in front of what?
Anyway, all of these triangles and quads costs speed and memory.
Um, 1mm, maximum edge length. It cost some memory, probably not just for the undo table entry.
Wow, 1mm costs a lot, but it’s smooth!
That’s with flat shading on, too. Drat! I wish I had put an environment map on it while it held that view.
[When creating 3D tetrahedron filled meshes for science stuff, on objects I created in Rhino, and exported, I once used up all 24GB of memory in my computer, under Linux, too, which boots with only 256MB. The mesher I used called the edge value thing “Wire discretization.” If you were going to break up the edge of your curve into segments, how long would you make them, or how long should the edge facets be?]
thanks so so much! that helped!!!
first time I use this forum, you are great guys
I’ve seen this kind of thing before. It seems that the simple slider only concerns itself with density, and not edges, needlessly not showing Rhino in it’s best light.
In V6, perhaps sliding the slider could decrease the maximum edge length, too.
Yeah…looks like the bug is that mesh is not regenerated - RefreshShade is needed. This works as expected in V6, so far.
-Pascal