Display Banding Anomalies in mac WIP

Rhino Rhino for Mac
1

I am getting some display anomalies from lofted surfaces in Mac WIP V5.4 (5e33w)

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It appears as though bands of the geometry on the flat surfaces are not orientated the same way and therefore appear shiny. See image…

Steps to Reproduce:

  • Create 2 planar closed crvs (i have not test with curvy crvs)
  • Move 1 crv up into parallel plane
  • Offset both crs
  • Loft the offset crvs
  • Loft the original crvs
  • PlanarSrf the 2 sets of crs (Original1 with offset1 and Original2 with offset2)
  • Join all

Should get a closed polysrf “tube” with banding error, see example attached below! Banding only occurs after the join?!

DisplayError.3dm (2.5 MB)

2

Even without opening your file, I’m going to hazard a guess that you have crease splitting turned off…

(opens file…)

Yes, exactly. Type CreaseSplitting and set it to “Yes” - looks like it’s set to “No”. That will fix it for future modeling.

To fix the existing model: select the object and run DivideAlongCreases > SplitAtKinks=Yes

How did crease splitting get turned off? That’s the sixty-four thousand dollar question. Sometimes it just “happens”, nobody knows why. I see this more frequently now on Mac Rhino.

–Mitch

2 Likes
3

Thanks Mitch, that did the trick!

4

Yeah, me too. A fix would be really welcomed.

Philip

5

Well, this bug has been around a long time, simply because nobody knows what causes it and thus how to fix it. As this setting is “exposed to the public”, it could be that:

  1. somehow people are accidentally setting it without realizing it
  2. some plug-in or script somewhere is doing it
  3. some obscure, very-infrequently used core code in Rhino is setting it (bug)
  4. none of the above…
  5. all of the above…

I guess we’ll just have to wait and see if V6 inherits this tendency from V5…

–Mitch

6

I know… Interesting times (waiting for V6) :sunglasses:

Philip