Strange offset results in Rhino 7

Rhino
1

Take a look at these 3 surfaces. Offset them all together and notice the results of the magenta surface.

image

This isn’t the first time we’ve seen this. Interestingly the Rhino 8 WIP also offsets incorrectly, but takes a lot longer to do it.

Here is the file if anyone wants to give this a try:

Strange offset.3dm (233.4 KB)

Thanks,

Dan

2

Hi Dan, checking it, thanks.
@DanBayn - that surface has ‘issues’…
Edge Tally:
16 boundary edges
Edge Tolerances: 0.528 to 2.005 <<<<< Here
median = 1.644 average = 1.453
Vertex Tolerances: 0.527 to 2.007 <<<<< Here
median = 1.556 average = 1.326

If you RebuildEdges, you’ll see how far off it is and it will all work again.

image
image793×497 6.11 KB

It is also a large underlying surface, I’d shrink it if there is no reason not to.

-Pascal

3

Hi Pascal,

Yeah, there’s something bizarre about that surface. Look how it comes into Fusion (there’s no surface offset in this image)

image
image1249×700 40.3 KB

I tried to shrink it and use RebuildEdges but it’s still pretty ugly (in Rhino 7 anyway, I didn’t try the WIP).

image
image1115×560 24.5 KB

Thanks for looking into it,

Dan