The "intersection" command again

Intersection command has been treated several times in the past.
In the last 2 years I think this command may have caused a Rhino crash at least 4 times a week (I know … it’s so much)
The problem is not so much the crash, but rather that it is not predictable.
I took the habit of saving the file before using intersection.
I often open an empty file where I cling the surfaces to be intersected, then copied and pasted into the initial file.
But sometimes the crash occurs equally. Often executing the command with many objects in the scene, Rhino crashes, forced exit is the only solution. Then restarting Rhino and repeating the command with the same objects, the intersection goes well …
In the past files were sent where the problem did not appear on the developer machines (not even after I restarted Rhino) or the problem was simply nodes that coincided with the intersection.
A definitive solution to this problem would be useful.
Thank you.


Are you intersecting “bad” objects?
Command: SelBadObjects
Are you running with CheckNewObjects turned on so you know when you get a bad object and can fix it?

What problem are you trying to solve by running Intersect between many objects at one time?

Hi John
No, I’m not intersecting bad objects,
I have explained badly, generally the intersection concerns 2 objects (2 surfaces or a surface and a curve) but with many other objects on the stage (in this case about 400 curves, 400 surfaces, 1 extrusion). The file can not be shared.
The aim is to obtain points or reference curves.
I attach a sample file to the last case presented yesterday (but as already written has already been done in the past without results)
Using “intersect” on these two surfaces with other objects on the scene, Rhino stuck. After a forced exit and a restart of Rhino, the command worked perfectly.
In practice (my feeling) it is as if Rhino had accumulated a limit memory amount and that the itersect command overcomes causing Rhino’s crash.

itersect.3dm (199.6 KB)

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Are you selecting all the objects to find the intersection between two objects? If so that may be the cause of the slowness because of the very large number of possible pairs of objects which intersect.

Does Rhino for Mac have the IntersectTwoSets command? It is a command in Rhino for Windows. t can be used instead of Intersect when the objects can be separated into two sets with only intersections between objects in different sets needed. IntersectTwoSets works much quicker than Intersect for large numbers of objects.

No, as I wrote the iteration is between two objects only.

fwiw, i’ve had a freeze or two since the mysterious intersect freeze was thought fixed… it’s definitely happening less often than before but i still do a save just prior to running Intersect since there’s a possibility i’ll be force quitting.

(at non-mac users-- this has been going on for a few years… Intersect can freeze rhino even with very simple intersections of two objects… say, two lines… no one has been able to come up with a set of steps or a file to show the behavior (that i know of)… it appears to happen randomly and requires a force quit of Rhino to get out of it… upon relaunching, the intersect will work fine.)

Yes Jeff, unfortunately it is just like that.

I’ve seen that too.