Hello to the community. While being a Rhino user for almost a decade I still sometimes cannot explain why some things are happening in the models that i make in Rhino.
I will share my frustration by giving an illustration to what I currently struggle to understand.
That should not happen, but it does tend to happen if that trimmed surface is a composite surface. That’s one reason to avoid surfaces with fully-multiple knots.
What does “connectivity” mean"?
If you want to join surfaces you need edges that match (within tolerance)
You should post the geometry if you want more than guesses about what’s going on.
It is not a polysurface if that you mean by saying composite surface. It is a lofted surface that is being rebuilt with 20 contol points
By connectivity I actually mean that the two parts intersect. Since i prepare this model for Finite Element Analysis i am trying to model it as precise as possible since that will save me time later.
OK this is a bug. For some reason the trimming is not accurate.
You can get it to trim accurately by first trimming with the big plane and then in a second trim operation trim with the small plane.
BTW your tolerance seems much tighter than it really needs to be. But if you are going to work with such tight tolerance you should change your display tolerance so that you can see if things are as accurate as you are asking them to be.
Yes its possible using that strategy could model the shape he wants more precisely, but there is nothing wrong with the surface as it is. The problem with the trim not being accurate is a bug. The bug is not the intersection code. The bug is a failure to create a trim boundary that agrees with the intersection curves. You get the correct boundary if you do the trimming in 2 steps.
The purpose of using this tolerance is because it gives me the “best compatibility” when i import it in spaceclaim from which i share topology and then perform the FE calculation.
Can you please let me know where I can change the display tolerance that you mention?
Its in the same place where you set the units (right below it)
I find it difficult to believe you can’t get it to work with looser tolerance, but if it necessary just be aware the tight tolerance can make modeling more difficult.
The bug is there even if you use 0.001 as tolerance
Hello - it looks like v6 gets this better but not perfect (with both trims at once) at the current file tolerance and does get it right with a more reasonable tolerance.