Error with Region Difference component in Grasshopper

When I try to make a region difference I get an error messange that says “No valid curves remained after projection in Group A” but I don’t see anything wrong with the curves.

These are the curves with which I want to use the component

But this is the result

I don’t know why it works with some curves but not with others.

Here is the file that makes the error (15.0 KB)

I hope anyone can tell me why this happens

It seems to be working fine on my end - is this the result you expected?

(A more robust way of doing this might be using Solid Difference to cut away 3d boxes before taking the contours)

Yes, that’s what I wanted. It’s strange how it doesn’t work for me. I wanted to do it that way beacause operations between curves are faster than operations between breps, but I think i’ll have to do it another way. Thanks.

Maybe try adjusting your document tolerance settings? I’m using the standard:

I think I have the same tolerance settings. I don’t undestand why it doesn’t work in my computer.


Are you both using the same Rhino version (Rhino 5 or Rhino 6) I see many bugs like this in Rhino 6 where the operation works fine in Rhino 5 but not 6.

yes this as well as Complex trimming of curves seems to go wrong only in Rhino 6 @DavidRutten

this issue seems not yet fixed in 6.6.18149.19261

I just fixed this issue today, there should be a new release candidate later today/early Wednesday depending on where you are in the World.

The problem was that Rhino started returning negative areas for certain shapes, and the region solver removes regions with an area less than the tolerance squared, thinking they are empty. The underlying negative-area problem has not yet been fixed, but Grasshopper now runs all area calculations through an Absolute function to fix it.

1 Like

I conflict the same error.
Is it already fixed?

Hi, I face the same problem. Is the release ready?

Best Jan