Hi,
So, i have a bunch of surfaces that have one orientation, when I join them into a polysurface the orientation changes. Apart from this it changes in the wrong way, and I cannot flip them again because they are joined.
Why is this happening?
Is it possible to flip surfaces that are part of a polysurface?
Please check attachment.
22-11-28-BC polysrf dirs.3dm (71.3 KB)
Definitely something weird with those surfaces - the direction flips in the middle, which shouldn’t happen.
(red are “backfaces”)
Maybe the UV directions? They look inconsistent? (a bit hard to tell on the phone)
well, Rhino sais … Trimmed Surface… SelBadObjects returns none… Degree 1, PointCount 2 looks clean…
Your surfaces overlap at that joint - by more than 0.5 at the top and 1.5 at the bottom… Zoom way in.
The JoinEdge message is actually accurate.
I dont get the join medssage, maybe because I use different tollerance?
If the surfaces join how come they have different orientations?
Again i’m not so much into how those things are fixed, but mostly why do they occur?
Problems like yours can occur because of imprecise modeling. If you replace the largest surface with a 4-point surface, there’s no problem at all.
Hi @Bogdan_Chipara
Three of the surfaces have 5 edges - something clearly went wrong with the trimming and it left behind tiny edges at the corners - and I guess that somehow it’s messing with the directions. I can’t help you as to why it happened, but if you manually re-trim the surfaces, they seem to join OK.
This is the upper left corner of the right rounded surface:
HTH, Jakob
yeah, well the fix is not so much of an interest…
I am more intersted in why those things happen. since the goemetry is very basic, comes from a polyline extrusion, some trims.
Something smart that can handle this kind of issues? maybe fix them? report them as bad?
more tools for analyse and debugging…
As I wrote above, you(r clicking actions) need to be precise when modeling.
yeah, well this is a precision of 1.5 mm on a building which is 90m by 56m . this is why those things occur. so im more like gathering scenarios.
the software also needs to be user friendly. maybe we should turn @Helvetosaur into a virtual assistant
It’s hard to see, off hand, how to avoid this completely in a free-for-all surface modeler - the edge overlap top and bottom makes a legitimate join at each so Rhino would have to know your intentions to disallow or automatically adjust here. One way would be to use JoinEdge instead of Join, and pay attention to the warning - that seems onerous to me, but it does convey your intention to Rhino.
Reliably recognizing a slightly weird edge configuration seems not realistic, to me, right at the moment anyway…
-Pascal
Hi @pascal , thanks for your thoughts!
Here’s a quick idea based on observation.
In many situations a geommetry will be bad if
1: there are too many digits which are not nice and round
2: geometry edit points too close to eachother. (100m building but points 1.5mm close)
So I was wandering, why not make a tool that pops up those 2 issues?
I have no interest in becoming ‘virtual’… 
rats.
-Pascal
Based on your level of experience the company might gather your dna and do a digital clone.
And, nice Kraftwerk! I saw them live! they looked like robots! 
Maybe they were! 
