I draw a simple shape, the curve is done with my normal curve tool, start tangent at top and head left and draw to suit curve I need. three clicks in effect, so a perfectly simple normal curve.
tool is called Interpolate curve, its the 2nd option of the curve tools, and command I see is _InterpCrv
used it millions of times since rhino v4
Drawn on Cplane. join it to rest of the shape on CPlane.
then project it to an angled sheet with a bend in it at wider end .
offset curve 0.025
mirror the result, all v simple.
draw three cross lines, check all for dir.
sweep2 AND FACETS APPEAR.
draw an extra cross line, just do the end and facets are gone.
prior to that tool curve, I did the blue curve in attached file, I had instead used an elipse then wanted a sharp tip so scaled it and trimmed it. then projected to the surface sheet. as above. then offsetCrv.
mirrored it, drew three cross lines,
THAT DIDNT GIVE FACETS.
However I have just revised the rear end USING AN ELIPSE, and now GET FACETS.
Until I add in extra lines, then they are gone.
why the difference in results ?
why cant sweep2 make a decent surface all the way when curve tool used is _InterpCrv ? sweep2 faceted.3dm (190.5 KB)
@Steve The surface facets are display artifacts caused by a combination of the number of spans in the surfaces the custom mesh settings you are using. The actual surfaces are smooth as can be seen in wireframe mode, or by selecting surface and looking at the highlighted edges and isolines.
Maximum angle should be in the range of 0.1 to 1.0. 15.0 is too large.
Minimum edge length should either bes set to â0â which result in Rhino using internal default, or a value in the range of 0.1 to 10 depending on the geometry. 0.0001 is too small.
Unless you have reason to change the settings use the âSmooth & slowerâ setting with âRefine meshâ checked.
@Gijs Sorry to bother you but this is the example of how the meshes preset were completly nonsense if you work in mm.
A minimum edge size of 0,0001 for any normal object other than a watch mechanims is pointless.
I think this is a leftover from Inches were this number make much more sense
Hi,
I need to see actual smooth curves on things on this project down to 0.05 inch diameter.
I got smooth curves when doing the front end and back end as separate sweeps, but they failed in a continual sweep, so why was that if my settings deny smooth curves ?
You say my settings are too coarse to do a smooth curve, ?
I am in inches here and mm is mentioned.
Not sure I follow
I used to get facets then Pascal showed me settings for smooth curves, so I stuck with those.
Each project uses previous project so I think they carried across.
The curves are smooth. The facets are in the image surfaces which appears on the screen, not in the curve data.
When you look at a surface in Rhino (other than a wireframe of the surface) on a screen you are actually seeing an image of a faceted mesh (called the render mesh) which Rhino creates from the NURBS surface data. If the render mesh is too coarse than it will be perceived as being faceted. If the render mesh is extremely fine then it can have so many facets that the display will be slow. So a compromise is needed - a mesh fine enough that it does not appear to be faceted but not so fine that display performance will be unacceptably slow.
The render mesh settings in Document Properties control how coarse or fine the render mesh is. If you see facets in the surface then you need to adjust the settings.
No itâs that people just donât understand the concept of meshing at all, like why itâs happening. That some of the settings are not 100 percent intuitiveâmost of them are!âis not the problem, 2 minutes of experimentation will show what they do.
Also note that people ALWAYS ask about this after sweeping one single surface, when by the time the model is filleted and joined, which massively increases the polygon count, the model will usually look fine even with the overly coarse default settings. So itâs like what we need to reduce the epidemic of people breaking their models trying to âfixâ this non-issue are separate settings for unjoined surfaces.
