Hi all.
I see the Rhino 7 offset sometime failed and the new one not, that’s good.
… but in attached cases those are simple flat polylines.
Skipping rectangular array and flip matrix, Rhino 7, 5ms:
… that’s the difference from a realtime execution and a stuttering execution.
Those are 31 trivial polylines.
Something is not right…?
I noticed the same, never able to debug why and ignored it since. Switched to Clipper for this single operation, for what it’s worth. Also faster
As far as I remember, Clipper do not create arcs. This is a rounded offset.
@Gijs can I tag you?
If I use a simple c# script to call the rhinocommon method:
private void RunScript(Curve C, double D, ref object O)
{
O = C.Offset(Plane.WorldXY, D, this.RhinoDocument.ModelAbsoluteTolerance, CurveOffsetCornerStyle.Round);
}
I get the same results: rhino 8 is 10x slower than rhino 7.
So this shouldn’t be a problem of grasshopper per se, but it’s about something deeper.
Offset has been rewritten in Rhino 8 to become more reliable. Maybe @Joshua_Kennedy can comment if the behavior you are experiencing is expected or not. Do you get the same factor 10 when performing a larger set of curves? (Not behind a pc right now to test this)
I did not notice this before, I’ll try to look this in detail on my next works.
I was creating an example file for kangaroo in the italian discourse, and I noticed offset produced glitchy results in Rhino 7.
Realtime kangaroo returned triangles, round offset sometime failed, but it was hard to pin-point the iterations where the bug occured
curve offset bug.gh (4.0 KB)
Rhino 7:
Rhino 8:
When I tried Rhino 8, I was glad to find the problem is already fixed. Offset curve is working better!
Cool! … but it is also way slower.
I instantly noticed because kangaroo were stuttering a lot over a bunch of geometries…
I’m looking into improving the speed of offset now. The issue is open here.
can you give some insights on how the offset - algorithm in Rhino 8 works?
RH-84100 is fixed in Rhino 8 Service Release 14 Release Candidate
Generation of the offset curve remains the same as previous versions of Rhino. What’s been implemented is a new trimming algorithm to remove self intersections in the generated offset curve. We use the method described in Polygon Offsetting by Computing Winding Numbers.